Cinnamon appears to fight inflammation and help insulin, a hormone that controls blood sugar. That news comes from researchers including Richard Anderson, PHD, CNS, of the U. S. Department of Agriculture Beltsville Human Nutrition Research Center in Beltsville, Md.
Anderson and colleagues presented two papers on cinnamon at the Experimental Biology 2006 meeting, held in San Francisco. In both studies, researchers did lab tests in an effort to find cinnamon's active ingredient that might affect diabetes.
Cinnamon In The Lab
One of Anderson's studies focused on cinnamon's insulin-like effects. In lab tests, Anderson's team found that cinnamon contains antioxidants called polyphenols that boost levels of three key proteins.
Those proteins are important in insulin signaling, glucose (blood sugar) transport, and inflammatory response, the researchers write. That study was partially funded by PhytoMedical Technologies, a company involved in pharmaceutical research on plant-based products, including cinnamon.
The second study probed cinnamon's chemistry. The researchers found and extracted a natural compound in cinnamon that they think may have insulin-like properties. The compound is a proanthocyanidin, which is a type of polyphenol.
Previous Work
Previously, Anderson tested cinnamon on people with type 2 diabetes. Diabetes patients took varying daily doses of cinnamon for 40 days. The doses were larger than levels typically used in food.
The patients' insulin sensitivity improved during the study. No differences were seen among the three doses of cinnamon.
Twenty days after the patients stopped taking cinnamon, those effects were fading but were still significant, meaning that they didn't seem to be due to chance, according to the study. Those findings were presented at the fourth International Congress Dietary Antioxidants and Trace Elements, held in Monastir, Tunisia, in April 2005.
Sources: Experimental Biology 2006, San Francisco, April 1-5, 2006. Agriculture Research Service, U.S. Department of Agriculture: "Research Project: Chromium and Polyphenols from Cinnamon in the Prevention and Alleviation of Glucose Intolerance." News release. Federation of American Societies for Experimental Biology.
Sunday, December 13, 2009
Blood Sugar Levels - Guidelines for Diabetes
Blood Glucose Goals - Desirable Blood Sugar Levels
Source: The American Diabetes Association's Complete Guide to Diabetes
Time of Test Person without diabetes Person with diabetes
Before meals Less than 115 mg/dl 80 to 120 mg/dl __________________________________________________________
Before bedtime Less than 120 mg/dl 100 to 140 mg/dl
Your Blood Glucose Goals
Choosing blood glucose goals can be easy. You can simply follow guidelines supported by the American Diabetes Association (see table). However, these goals may not be easy for you to reach. Or they may not be appropriate for you because of a health problem. Your goals may be consistently higher. Why not see what your blood glucose levels are before and after meals and before bed and compare them to the goals in the table. Perhaps you can make small changes, a few at a time, to slowly lower your blood glucose levels.
Changes may include:
* how much food you eat
* the kinds of food you eat
* how much exercise you get
* how much insulin or medication you take.
Whether you have type 1 or type II diabetes or gestational diabetes, the goals of achieving control of blood glucose levels are similar: to keep blood glucose as close as possible to that of a person without diabetes. For many people with diabetes, getting normal blood glucose levels (like a person without diabetes) just isn't realistic or even desirable. For instance, if you are elderly and live alone, you may be more concerned with preventing severe low blood glucose than avoiding long-term complications. You and your health care team should decide together what goals are best for you.
Tips: Blood glucose goals for children are looser. For example, the target range may be 100 or 200 mg/dl. Most children under the age of 6 or 7 are not yet able to be aware of and respond to oncoming low blood glucose, and it's very important to limit episodes of low blood glucose. Tailor goals to the age and abilities of the child and be flexible with goals as the child grows.
Source: The American Diabetes Association's Complete Guide to Diabetes
Time of Test Person without diabetes Person with diabetes
Before meals Less than 115 mg/dl 80 to 120 mg/dl __________________________________________________________
Before bedtime Less than 120 mg/dl 100 to 140 mg/dl
Your Blood Glucose Goals
Choosing blood glucose goals can be easy. You can simply follow guidelines supported by the American Diabetes Association (see table). However, these goals may not be easy for you to reach. Or they may not be appropriate for you because of a health problem. Your goals may be consistently higher. Why not see what your blood glucose levels are before and after meals and before bed and compare them to the goals in the table. Perhaps you can make small changes, a few at a time, to slowly lower your blood glucose levels.
Changes may include:
* how much food you eat
* the kinds of food you eat
* how much exercise you get
* how much insulin or medication you take.
Whether you have type 1 or type II diabetes or gestational diabetes, the goals of achieving control of blood glucose levels are similar: to keep blood glucose as close as possible to that of a person without diabetes. For many people with diabetes, getting normal blood glucose levels (like a person without diabetes) just isn't realistic or even desirable. For instance, if you are elderly and live alone, you may be more concerned with preventing severe low blood glucose than avoiding long-term complications. You and your health care team should decide together what goals are best for you.
Tips: Blood glucose goals for children are looser. For example, the target range may be 100 or 200 mg/dl. Most children under the age of 6 or 7 are not yet able to be aware of and respond to oncoming low blood glucose, and it's very important to limit episodes of low blood glucose. Tailor goals to the age and abilities of the child and be flexible with goals as the child grows.
Influence Of 'Obesity Gene' Can Be Offset By Healthy Diet
Children who carry a gene strongly associated with obesity could offset its effect by eating a low energy density diet, according to new research from UCL (University College London) and the University of Bristol published
The study, based on data from a sample of 2275 children from the Bristol-based ALSPAC study (Children of the 90s) provides evidence that people might be able to avoid becoming obese if they adopt a healthier diet with a low energy density – even those who carry the FTO gene, identified as being a high risk gene for obesity.
Dietary energy density (DED) refers to the amount of energy consumed per unit weight of food, or number of calories per bite. A low dietary energy density can be achieved by eating lots of water-rich foods like fruits and vegetables and limiting foods high in fat and sugar like chocolate and biscuits.
The researchers looked at how DED affected the build up of fat in the body over a period of three years in children aged between 10 and 13 years old. They found that children with a more energy dense diet (more calories per bite) tended to have more fat mass three years later and also confirmed that those carrying the high risk gene had greater fat mass overall.
When the researchers looked at whether children with the FTO gene had a stronger reaction to an energy dense diet than children with a lower genetic risk they found that they did not. These results indicate that if a child with a high genetic risk eats a diet with fewer calories per bite, they may be able to offset the effect of the gene on weight gain and so stay a healthy weight.
Lead author Dr Laura Johnson, UCL Epidemiology and Public Health, said: "This is an important finding because it provides evidence that it's easier to eat too much energy and gain weight when your diet is packed tight with calories, so adopting a diet with more bulk and less energy per bite could help people avoid becoming obese regardless of their genetic risk. Obesity is not inevitable if your genes give you a higher risk because if you change the types of foods you eat this will help curb excessive weight gain."
"This shows that although our genetic make-up does have an influence on our health, it's certainly not the only defining factor. Those with high risk genes can, in some cases, resist their genetic lot if they alter their lifestyle in the right way – in this case, their diet."
FTO is the first common obesity gene to be identified in Caucasian populations. Previous studies have shown that adults with two copies of the FTO gene are on average 3kg heavier, and individuals with a single copy are on average 1.5kg heavier, than those without the gene.
The data was taken from the Avon Longitudinal Study of Parents and Children (ALSPAC) and analysis was carried out by researchers at UCL, Bristol University, Peninsula Medical School, and MRC Human Nutrition Research in Cambridge.
The study, based on data from a sample of 2275 children from the Bristol-based ALSPAC study (Children of the 90s) provides evidence that people might be able to avoid becoming obese if they adopt a healthier diet with a low energy density – even those who carry the FTO gene, identified as being a high risk gene for obesity.
Dietary energy density (DED) refers to the amount of energy consumed per unit weight of food, or number of calories per bite. A low dietary energy density can be achieved by eating lots of water-rich foods like fruits and vegetables and limiting foods high in fat and sugar like chocolate and biscuits.
The researchers looked at how DED affected the build up of fat in the body over a period of three years in children aged between 10 and 13 years old. They found that children with a more energy dense diet (more calories per bite) tended to have more fat mass three years later and also confirmed that those carrying the high risk gene had greater fat mass overall.
When the researchers looked at whether children with the FTO gene had a stronger reaction to an energy dense diet than children with a lower genetic risk they found that they did not. These results indicate that if a child with a high genetic risk eats a diet with fewer calories per bite, they may be able to offset the effect of the gene on weight gain and so stay a healthy weight.
Lead author Dr Laura Johnson, UCL Epidemiology and Public Health, said: "This is an important finding because it provides evidence that it's easier to eat too much energy and gain weight when your diet is packed tight with calories, so adopting a diet with more bulk and less energy per bite could help people avoid becoming obese regardless of their genetic risk. Obesity is not inevitable if your genes give you a higher risk because if you change the types of foods you eat this will help curb excessive weight gain."
"This shows that although our genetic make-up does have an influence on our health, it's certainly not the only defining factor. Those with high risk genes can, in some cases, resist their genetic lot if they alter their lifestyle in the right way – in this case, their diet."
FTO is the first common obesity gene to be identified in Caucasian populations. Previous studies have shown that adults with two copies of the FTO gene are on average 3kg heavier, and individuals with a single copy are on average 1.5kg heavier, than those without the gene.
The data was taken from the Avon Longitudinal Study of Parents and Children (ALSPAC) and analysis was carried out by researchers at UCL, Bristol University, Peninsula Medical School, and MRC Human Nutrition Research in Cambridge.
Western Diets Turn on Fat Genes: Energy-Dense Foods May Activate Genes That Ultimately Make Us Obese
This means these foods hit you with a double-whammy as the already difficult task of converting high-fat and high-sugar foods to energy is made even harder because these foods also turn our bodies into "supersized fat-storing" machines.
In the research report, scientists show that foods high in fat and sugar stimulate a known opioid receptor, called the kappa opioid receptor, which plays a role in fat metabolism. When this receptor is stimulated, it causes our bodies to hold on to far more fat than our bodies would do otherwise.
According to Traci Ann Czyzyk-Morgan, one of the researchers involved in the work, "the data presented here support the hypothesis that overactivation of kappa opioid receptors contribute to the development of obesity specifically during prolonged consumption of high-fat, calorically dense diets."
To make this discovery, Czyzyk-Morgan and her colleagues conducted tests in two groups of mice. One group had the kappa opioid receptor genetically deactivated ("knocked out") and the other group was normal. Both groups were given a high fat, high sucrose, energy dense diet for 16 weeks. While the control group of mice gained significant weight and fat mass on this diet, the mice with the deactivated receptor remained lean. In addition to having reduced fat stores, the mice with the deactivated receptor also showed a reduced ability to store incoming nutrients.
Although more work is necessary to examine what the exact effects would be in humans, this research may help address the growing obesity problem worldwide in both the short-term and long-term. Most immediately, this research provides more proof that high-fat and high-sugar diets should be avoided. In the long-term, however, this research is even more significant, as it provides a new drug target for developing therapies for preventing obesity and helping obese people slim down.
"In times when food was scarce and starvation an ever-present threat, an adaptation that allows our bodies to store as much energy as possible during plentiful times was probably a lifesaver," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "By taking that opioid receptor off the table, researchers may have found a way to keep us from eating ourselves to death."
Aerobic exercise
In physical exercise, aerobic exercise is complementary to anaerobic exercise
Aerobic literally means "with oxygen", and refers to the use of oxygen in muscles' energy-generating process.
Aerobic exercise includes any type of exercise, typically those performed at moderate levels of intensity for extended periods of time, that maintains an increased heart rate.
In such exercise, oxygen is used to "burn" fats and glucose in order to produce adenosine triphosphate, the basic energy carrier for all cells.
Initially during aerobic exercise, glycogen is broken down to produce glucose, but in its absence, fat metabolism is initiated instead.
The latter is a slow process, and is accompanied by a decline in performance level.
The switch to fat as fuel is a major cause of what marathon runners call "hitting the wall." There are various types of aerobic exercise.
In general, aerobic exercise is one performed at a moderately high level of intensity over a long period of time.
For example, running a long distance at a moderate pace is an aerobic exercise, but sprinting is not.
Playing singles tennis, with near-continuous motion, is generally considered aerobic activity, while golf or doubles tennis, with their more frequent breaks, may not be..
Aerobic literally means "with oxygen", and refers to the use of oxygen in muscles' energy-generating process.
Aerobic exercise includes any type of exercise, typically those performed at moderate levels of intensity for extended periods of time, that maintains an increased heart rate.
In such exercise, oxygen is used to "burn" fats and glucose in order to produce adenosine triphosphate, the basic energy carrier for all cells.
Initially during aerobic exercise, glycogen is broken down to produce glucose, but in its absence, fat metabolism is initiated instead.
The latter is a slow process, and is accompanied by a decline in performance level.
The switch to fat as fuel is a major cause of what marathon runners call "hitting the wall." There are various types of aerobic exercise.
In general, aerobic exercise is one performed at a moderately high level of intensity over a long period of time.
For example, running a long distance at a moderate pace is an aerobic exercise, but sprinting is not.
Playing singles tennis, with near-continuous motion, is generally considered aerobic activity, while golf or doubles tennis, with their more frequent breaks, may not be..
Physical exercise
Physical exercise is the performance of some activity in order to develop or maintain physical fitness and overall health
It is often directed toward also honing athletic ability or skill.
Frequent and regular physical exercise is an important component in the prevention of some diseases such as heart disease, cardiovascular disease, Type 2 diabetes and obesity.
Exercises are generally grouped into three types depending on the overall effect they have on the human body: Flexibility exercises such as stretching improve the range of motion of muscles and joints; aerobic exercises such as walking and running focus on increasing cardiovascular endurance; and anaerobic exercises such as weight training, functional training or sprinting increase short-term muscle strength. Physical exercise is considered important for maintaining physical fitness including healthy weight; building and maintaining healthy bones, muscles, and joints; promoting physiological well-being; reducing surgical risks; and strengthening the immune system..
It is often directed toward also honing athletic ability or skill.
Frequent and regular physical exercise is an important component in the prevention of some diseases such as heart disease, cardiovascular disease, Type 2 diabetes and obesity.
Exercises are generally grouped into three types depending on the overall effect they have on the human body: Flexibility exercises such as stretching improve the range of motion of muscles and joints; aerobic exercises such as walking and running focus on increasing cardiovascular endurance; and anaerobic exercises such as weight training, functional training or sprinting increase short-term muscle strength. Physical exercise is considered important for maintaining physical fitness including healthy weight; building and maintaining healthy bones, muscles, and joints; promoting physiological well-being; reducing surgical risks; and strengthening the immune system..
General fitness training
General fitness training works towards broad goals of overall health and well-being, rather than narrow goals of sport competition, larger muscles or concerns over appearance.
A regular moderate workout regimen and healthy diet can improve general appearance markers of good health such as muscle tone, healthy skin, hair and nails, while minimizing age or lifestyle-related reductions in health..
A regular moderate workout regimen and healthy diet can improve general appearance markers of good health such as muscle tone, healthy skin, hair and nails, while minimizing age or lifestyle-related reductions in health..
Friday, December 11, 2009
Thursday, December 10, 2009
Brain Activity Exposes Those Who Break Promises
Scientists from the University of Zurich have discovered the physiological mechanisms in the brain that underlie broken promises. Patterns of brain activity even enable predicting whether someone will break a promise.
Mathematical Model of Simple Circuit in Chicken Brain Raises Fundamental Questions About Neural Circuitry
The Web site Neuroanthropology asks visitors to complete this quote, "One of the difficulties in understanding the brain is …." In addition to the typical facetious remarks, such as "so few of us seem to have one" and "the damn thing is smart enough to realize what you are doing, and contrary enough to change the way it reacts just to spite you…," there are more serious ones, such as "… it's not a computer" and the methods we have available "are not enough accurate in saying how neural mechanisms correlates to behavior."
Migraine Headaches And Sexual Desire May Be Linked
Contrary to the popular cliché, "Not tonight, I have a headache," new research suggests that not all headache sufferers avoid sexual activity. In fact, migraine sufferers reported higher levels of sexual desire than those with other types of headaches, according to researchers from Wake Forest University School of Medicine and colleagues.
Exercise Program Reduces Migraine Suffering
While physical exercise has been shown to trigger migraine headaches among sufferers, a new study describes an exercise program that is well tolerated by patients. The findings show that the program decreased the frequency of headaches and improved quality of life.
The study used a sample of migraine sufferers who were examined before, during and after an aerobic exercise intervention. The program was based on indoor cycling (for continuous aerobic exercise) and was designed to improve maximal oxygen uptake without worsening the patients’ migraines.
After the treatment period, patients’ maximum oxygen uptake increased significantly. There was no worsening of migraine status at any time during the study period and, during the last month of treatment, there was a significant decrease in the number of migraine attacks, the number of days with migraine per month, headache intensity and amount of headache medication used.
Individuals with headache and migraine typically are less physically active than those without headache. Patients with migraine often avoid exercise, resulting in less aerobic endurance and flexibility. Therefore, well designed studies of exercise in patients with migraine are imperative.
“While the optimal amount of exercise for patients with migraine remains unknown, our evaluated program can now be tested further and compared to pharmacological and non-pharmacological treatments to see if exercise can prevent migraine,” says Dr. Emma Varkey, co-author of the study.
The study is published in Headache: The Journal of Head and Face Pain.
The study used a sample of migraine sufferers who were examined before, during and after an aerobic exercise intervention. The program was based on indoor cycling (for continuous aerobic exercise) and was designed to improve maximal oxygen uptake without worsening the patients’ migraines.
After the treatment period, patients’ maximum oxygen uptake increased significantly. There was no worsening of migraine status at any time during the study period and, during the last month of treatment, there was a significant decrease in the number of migraine attacks, the number of days with migraine per month, headache intensity and amount of headache medication used.
Individuals with headache and migraine typically are less physically active than those without headache. Patients with migraine often avoid exercise, resulting in less aerobic endurance and flexibility. Therefore, well designed studies of exercise in patients with migraine are imperative.
“While the optimal amount of exercise for patients with migraine remains unknown, our evaluated program can now be tested further and compared to pharmacological and non-pharmacological treatments to see if exercise can prevent migraine,” says Dr. Emma Varkey, co-author of the study.
The study is published in Headache: The Journal of Head and Face Pain.
Exercise Program Reduces Migraine Suffering
While physical exercise has been shown to trigger migraine headaches among sufferers, a new study describes an exercise program that is well tolerated by patients. The findings show that the program decreased the frequency of headaches and improved quality of life.
Treating Cluster Headaches With High-Flow Oxygen Appears Effective
Patients with a cluster headache, which is characterized by bouts of excruciating pain usually near the eye or temple, were more likely to report being pain-free within 15 minutes of treatment with high-flow oxygen than patients who received a placebo treatment, according to a study in the December 9 issue of JAMA.
Cluster headache attacks typically last for 15 minutes to 3 hours untreated and have a frequency of 1 every other day for up to 8 attacks a day. Attacks usually occur in bouts, or clusters, lasting for weeks or months, separated by remissions lasting months or years, according to background information in the article. The current treatment for acute attacks of cluster headache is injection with the drug sumatriptan, but frequent dosing is not recommended because of adverse effects. Another treatment option is the inhalation of high-dose, high-flow oxygen, but its use may be limited because of the lack of a good quality controlled trial.
Anna S. Cohen, Ph.D., M.R.C.P., of the National Hospital for Neurology and Neurosurgery, London, and colleagues conducted a randomized, placebo-controlled trial of high-flow oxygen for the treatment of acute attacks of cluster headache. The study included 109 adults (ages 18-70 years). Patients treated four cluster headache episodes alternately with high-flow oxygen (inhaled oxygen at 100 percent, 12 L/min, delivered by face mask, for 15 minutes at the start of an attack) or placebo (high-flow air). Patients were recruited and followed up between 2002 and 2007. The final analysis included 57 patients with episodic cluster headache and 19 with chronic cluster headache.
The researchers found that 78 percent of the patients who received oxygen reported being pain-free or to have adequate relief within 15 minutes of treatment, compared to 20 percent of patients who received air. For other outcomes, such as being pain-free at 30 minutes or a reduction in pain up to 60 minutes, treatment with oxygen was superior to air. There were no serious adverse events related to the treatments.
"To our knowledge, this is the first adequately powered trial of high-flow oxygen compared with placebo, and it confirms clinical experience and current guidelines that inhaled oxygen can be used as an acute attack therapy for episodic and chronic cluster headache," the authors write.
"This work paves the way for further studies to optimize the administration of oxygen and its more widespread use as an acute attack treatment in cluster headache, offering an evidence-based alternative to those who cannot take triptan agents."
Cluster headache attacks typically last for 15 minutes to 3 hours untreated and have a frequency of 1 every other day for up to 8 attacks a day. Attacks usually occur in bouts, or clusters, lasting for weeks or months, separated by remissions lasting months or years, according to background information in the article. The current treatment for acute attacks of cluster headache is injection with the drug sumatriptan, but frequent dosing is not recommended because of adverse effects. Another treatment option is the inhalation of high-dose, high-flow oxygen, but its use may be limited because of the lack of a good quality controlled trial.
Anna S. Cohen, Ph.D., M.R.C.P., of the National Hospital for Neurology and Neurosurgery, London, and colleagues conducted a randomized, placebo-controlled trial of high-flow oxygen for the treatment of acute attacks of cluster headache. The study included 109 adults (ages 18-70 years). Patients treated four cluster headache episodes alternately with high-flow oxygen (inhaled oxygen at 100 percent, 12 L/min, delivered by face mask, for 15 minutes at the start of an attack) or placebo (high-flow air). Patients were recruited and followed up between 2002 and 2007. The final analysis included 57 patients with episodic cluster headache and 19 with chronic cluster headache.
The researchers found that 78 percent of the patients who received oxygen reported being pain-free or to have adequate relief within 15 minutes of treatment, compared to 20 percent of patients who received air. For other outcomes, such as being pain-free at 30 minutes or a reduction in pain up to 60 minutes, treatment with oxygen was superior to air. There were no serious adverse events related to the treatments.
"To our knowledge, this is the first adequately powered trial of high-flow oxygen compared with placebo, and it confirms clinical experience and current guidelines that inhaled oxygen can be used as an acute attack therapy for episodic and chronic cluster headache," the authors write.
"This work paves the way for further studies to optimize the administration of oxygen and its more widespread use as an acute attack treatment in cluster headache, offering an evidence-based alternative to those who cannot take triptan agents."
Methamphetamine Abuse Linked To Underage Sex, Smoking And Drinking
Children and adolescents who abuse alcohol or are sexually active are more likely to take methamphetamines (MA), also known as 'meth' or 'speed'. New research reveals the risk factors associated with MA use, in both low-risk children (those who don't take drugs) and high-risk children (those who have taken other drugs or who have ever attended juvenile detention centres).
MA is a stimulant, usually smoked, snorted or injected. It produces sensations of euphoria, lowered inhibitions, feelings of invincibility, increased wakefulness, heightened sexual experiences, and hyperactivity resulting from increased energy for extended periods of time. According to the lead author of this study, Terry P. Klassen of the University of Alberta, Canada, "MA is produced, or 'cooked', quickly, reasonably simply, and cheaply by using legal and readily available ingredients with recipes that can be found on the internet".
Because of the low cost, ready availability and legal status of the drug, long-term use can be a serious problem. In order to assess the risk factors that are associated with people using MA, Klassen and his team carried out an analysis of twelve different medical studies, combining their results to get a bigger picture of the MA problem. They said, "Within the low-risk group, there were some clear patterns of risk factors associated with MA use. A history of engaging in behaviors such as sexual activity, alcohol consumption and smoking was significantly associated with MA use among low-risk youth. Engaging in these kinds of behaviors may be a gateway for MA use or vice versa. A homosexual or bisexual lifestyle is also a risk factor."
Amongst high-risk youth, the risk factors the authors identified were, "growing up in an unstable family environment (e.g., family history of crime, alcohol use and drug use) and having received treatment for psychiatric conditions. Among high-risk youth, being female was also a risk factor".
MA is a stimulant, usually smoked, snorted or injected. It produces sensations of euphoria, lowered inhibitions, feelings of invincibility, increased wakefulness, heightened sexual experiences, and hyperactivity resulting from increased energy for extended periods of time. According to the lead author of this study, Terry P. Klassen of the University of Alberta, Canada, "MA is produced, or 'cooked', quickly, reasonably simply, and cheaply by using legal and readily available ingredients with recipes that can be found on the internet".
Because of the low cost, ready availability and legal status of the drug, long-term use can be a serious problem. In order to assess the risk factors that are associated with people using MA, Klassen and his team carried out an analysis of twelve different medical studies, combining their results to get a bigger picture of the MA problem. They said, "Within the low-risk group, there were some clear patterns of risk factors associated with MA use. A history of engaging in behaviors such as sexual activity, alcohol consumption and smoking was significantly associated with MA use among low-risk youth. Engaging in these kinds of behaviors may be a gateway for MA use or vice versa. A homosexual or bisexual lifestyle is also a risk factor."
Amongst high-risk youth, the risk factors the authors identified were, "growing up in an unstable family environment (e.g., family history of crime, alcohol use and drug use) and having received treatment for psychiatric conditions. Among high-risk youth, being female was also a risk factor".
Most Internet Sex Offenders Aim At Teens
Contrary to stereotype, most Internet sex offenders are not adults who target young children by posing as another youth, luring children to meetings, and then abducting or forcibly raping them, according to researchers who have studied the nature of Internet-initiated sex crimes.
Rather, most online sex offenders are adults who target teens and seduce victims into sexual relationships. They take time to develop the trust and confidence of victims, so that the youth see these relationships as romances or sexual adventures. The youth most vulnerable to online sex offenders have histories of sexual or physical abuse, family problems, and tendencies to take risks both on- and offline, the researchers say.
In short, the researchers draw a clearer picture about adults who troll the Internet for sex with minors in the study, "Online 'Predators' and Their Victims: Myths, Realities and Implications for Prevention," published in the February/March issue of American Psychologist.
The study was based on three surveys--two comprising telephone interviews of a combined 3,000 Internet users between the ages of 10 and 17; first in 2000 and again in 2005; and one involving 612 interviews with federal, state and local law enforcement officials in the United States between October 2001 and July 2002.
"To prevent these crimes, we need accurate information about their true dynamics," said Janis Wolak, lead author of the study. "The things that we hear and fear and the things that actually occur may not be the same. The newness of the environment makes it hard to see where the danger is."
For example, in spite of public concern, the authors found that adolescents' use of popular social networking sites such as MySpace and Facebook do not appear to increase their risk of being victimized by online predators. Rather, it is risky online interactions such as talking online about sex to unknown people that increases vulnerability, according to the researchers.
"Most Internet-initiated sex crimes involve adult men who are open about their interest in sex," Wolak said. "The offenders use instant messages, e-mail and chat rooms to meet and develop intimate relationships with their victims. In most of the cases, the victims are aware that they are talking online with adults."
"A majority of the offenders are charged with crimes such as statutory rape, that involve non-forcible sexual activity with adolescent victims who are too young to consent to sexual intercourse with adults," she added.
Current educational efforts that are focused on discouraging children from giving out or posting personal information, warning about deception online, and urging parents to monitor their children may not be effective, according to the authors.
Wolak and her colleagues say more effort should be directed at helping teens appreciate the drawbacks and inappropriateness of romantic relationships with adults. These efforts should include frank discussions of the dynamics of Internet-initiated sex crimes. Since many of the victims do not have good relationships with parents, ways to reach vulnerable teens directly, through sources they find credible, need to be found.
Among the study's other findings:
Internet offenders pretended to be teenagers in only 5 percent of the crimes studied by researchers.
Nearly 75 percent of victims who met offenders face-to-face did so more than once.
Online sex offenders are seldom violent, and cases involving stalking or abduction are very rare.
Youth who engaged in four or more risky online behaviors were much more likely to report receiving online sexual solicitations. The online risky behaviors included maintaining buddy lists that included strangers, discussing sex online with people they did not know in person and being rude or nasty online.
Boys who are gay or are questioning their sexuality may be more susceptible to Internet-initiated sex crimes than other populations. Researchers found boys were the victims in nearly one-quarter of criminal cases, and most cases included facts that suggested victims were gay or questioning their sexuality.
Journal reference: Online "Predators" and Their Victims: Myths, Realities, and Implications for Prevention and Treatment, Janis Wolak, PhD, David Finkelhor, PhD and Kimberley J. Mitchell, PhD Crimes Against Children Center at the University of New Hampshire and Michelle L. Ybarra, PhD, Internet Solutions for Kids, Inc., American Psychologist, Vol. 63, No.2.
*These studies were conducted by the authors, Janis Wolak, JD, David Finkelhor, PhD, Kimberly Mitchell, PhD and Michele Ybarra, PhD, at the Crimes against Children Research Center, University of New Hampshire.
Rather, most online sex offenders are adults who target teens and seduce victims into sexual relationships. They take time to develop the trust and confidence of victims, so that the youth see these relationships as romances or sexual adventures. The youth most vulnerable to online sex offenders have histories of sexual or physical abuse, family problems, and tendencies to take risks both on- and offline, the researchers say.
In short, the researchers draw a clearer picture about adults who troll the Internet for sex with minors in the study, "Online 'Predators' and Their Victims: Myths, Realities and Implications for Prevention," published in the February/March issue of American Psychologist.
The study was based on three surveys--two comprising telephone interviews of a combined 3,000 Internet users between the ages of 10 and 17; first in 2000 and again in 2005; and one involving 612 interviews with federal, state and local law enforcement officials in the United States between October 2001 and July 2002.
"To prevent these crimes, we need accurate information about their true dynamics," said Janis Wolak, lead author of the study. "The things that we hear and fear and the things that actually occur may not be the same. The newness of the environment makes it hard to see where the danger is."
For example, in spite of public concern, the authors found that adolescents' use of popular social networking sites such as MySpace and Facebook do not appear to increase their risk of being victimized by online predators. Rather, it is risky online interactions such as talking online about sex to unknown people that increases vulnerability, according to the researchers.
"Most Internet-initiated sex crimes involve adult men who are open about their interest in sex," Wolak said. "The offenders use instant messages, e-mail and chat rooms to meet and develop intimate relationships with their victims. In most of the cases, the victims are aware that they are talking online with adults."
"A majority of the offenders are charged with crimes such as statutory rape, that involve non-forcible sexual activity with adolescent victims who are too young to consent to sexual intercourse with adults," she added.
Current educational efforts that are focused on discouraging children from giving out or posting personal information, warning about deception online, and urging parents to monitor their children may not be effective, according to the authors.
Wolak and her colleagues say more effort should be directed at helping teens appreciate the drawbacks and inappropriateness of romantic relationships with adults. These efforts should include frank discussions of the dynamics of Internet-initiated sex crimes. Since many of the victims do not have good relationships with parents, ways to reach vulnerable teens directly, through sources they find credible, need to be found.
Among the study's other findings:
Internet offenders pretended to be teenagers in only 5 percent of the crimes studied by researchers.
Nearly 75 percent of victims who met offenders face-to-face did so more than once.
Online sex offenders are seldom violent, and cases involving stalking or abduction are very rare.
Youth who engaged in four or more risky online behaviors were much more likely to report receiving online sexual solicitations. The online risky behaviors included maintaining buddy lists that included strangers, discussing sex online with people they did not know in person and being rude or nasty online.
Boys who are gay or are questioning their sexuality may be more susceptible to Internet-initiated sex crimes than other populations. Researchers found boys were the victims in nearly one-quarter of criminal cases, and most cases included facts that suggested victims were gay or questioning their sexuality.
Journal reference: Online "Predators" and Their Victims: Myths, Realities, and Implications for Prevention and Treatment, Janis Wolak, PhD, David Finkelhor, PhD and Kimberley J. Mitchell, PhD Crimes Against Children Center at the University of New Hampshire and Michelle L. Ybarra, PhD, Internet Solutions for Kids, Inc., American Psychologist, Vol. 63, No.2.
*These studies were conducted by the authors, Janis Wolak, JD, David Finkelhor, PhD, Kimberly Mitchell, PhD and Michele Ybarra, PhD, at the Crimes against Children Research Center, University of New Hampshire.
If You're Feeling Helpless, It May Be Best To Be Alone
If you're going to experience a period of helplessness, it's best to be alone. New research at the University of Haifa found that laboratory rats that were on their own when exposed to uncontrollable conditions, which create a feeling of helplessness, learned to avoid situations which create such feelings better than rats that were exposed to uncontrollable conditions in pairs.
The way laboratory rats react to uncontrollable situations in which their behaviors have no influence on subsequent events has been researched in the past. Results show that rats that are exposed to a situation in which they are powerless, for example, electric shocks that they can't possibly avoid, have a more difficult time learning how to avoid them in the future than rats that were never exposed to situations of helplessness -- a phenomenon known as "learned helplessness."
Researchers choose to experiment with rats because they are know as social animals and their brains work much the same way as human brains. However, most of the research done until now was done on rats exposed to uncontrollable conditions when they are alone.
In his doctoral dissertation, Dr. Qutaiba Agbaria, under the supervision of Dr. Richard Shuster, examined the differences in learned helplessness among rats that were exposed to uncontrollable conditions alone and in pairs. The researcher began with the hypothesis that rats would learn to be more adaptable in social situations, or in pairs, however, the research results revealed a very different picture. Rats that were exposed to uncontrollable conditions in pairs coped less well when they were no longer in uncontrollable situations than rats that were exposed to these situations alone.
The next phase of the research examined the influence of a rat that had never been exposed to an uncontrollable situation on a rat that had. These pairs of rats showed greater adaptability than pairs that had been exposed to helplessness as individuals or in pairs. In addition, the researchers did not find outstanding differences between the learning ability of these pairs of rats -- where one had been exposed to uncontrollable conditions and the other hadn't -- and pairs that were never exposed to uncontrollable conditions, which means that the effect of "learned helplessness" is effectively erased. "Now that we have see that "learned helplessness" can be "unlearned", we should continue to examine whether this change is a result of exposure to a rat that was not exposed to helplessness or rather that the social behavior between the two animals has another meaning," said Dr. Agbaria.
The way laboratory rats react to uncontrollable situations in which their behaviors have no influence on subsequent events has been researched in the past. Results show that rats that are exposed to a situation in which they are powerless, for example, electric shocks that they can't possibly avoid, have a more difficult time learning how to avoid them in the future than rats that were never exposed to situations of helplessness -- a phenomenon known as "learned helplessness."
Researchers choose to experiment with rats because they are know as social animals and their brains work much the same way as human brains. However, most of the research done until now was done on rats exposed to uncontrollable conditions when they are alone.
In his doctoral dissertation, Dr. Qutaiba Agbaria, under the supervision of Dr. Richard Shuster, examined the differences in learned helplessness among rats that were exposed to uncontrollable conditions alone and in pairs. The researcher began with the hypothesis that rats would learn to be more adaptable in social situations, or in pairs, however, the research results revealed a very different picture. Rats that were exposed to uncontrollable conditions in pairs coped less well when they were no longer in uncontrollable situations than rats that were exposed to these situations alone.
The next phase of the research examined the influence of a rat that had never been exposed to an uncontrollable situation on a rat that had. These pairs of rats showed greater adaptability than pairs that had been exposed to helplessness as individuals or in pairs. In addition, the researchers did not find outstanding differences between the learning ability of these pairs of rats -- where one had been exposed to uncontrollable conditions and the other hadn't -- and pairs that were never exposed to uncontrollable conditions, which means that the effect of "learned helplessness" is effectively erased. "Now that we have see that "learned helplessness" can be "unlearned", we should continue to examine whether this change is a result of exposure to a rat that was not exposed to helplessness or rather that the social behavior between the two animals has another meaning," said Dr. Agbaria.
Mobile Phones Affect Memory
Can radiation from cell phones affect the memory? Yes -- at least it appears to do so in rat experiments conducted at the Division of Neurosurgery, Lund University, in Sweden. Henrietta Nittby studied rats that were exposed to mobile phone radiation for two hours a week for more than a year. These rats had poorer results on a memory test than rats that had not been exposed to radiation.
The memory test consisted of releasing the rats in a box with four objects mounted in it. These objects were different on the two occasions, and the placement of the objects was different from one time to the other.
The memory test consisted of releasing the rats in a box with four objects mounted in it. These objects were different on the two occasions, and the placement of the objects was different from one time to the other.
Thursday, December 3, 2009
Breath
Breathing transports oxygen into the body and carbon dioxide out of the body.
Aerobic organisms require oxygen to create energy via respiration, in the form of energy-rich molecules such as glucose..
Aerobic organisms require oxygen to create energy via respiration, in the form of energy-rich molecules such as glucose..
Gas exchange
Gas exchange or respiration takes place at a respiratory surface; a boundary between the external environment and the interior of the body
For unicellular organisms the respiratory surface is simply the cell membrane, but for large organisms it usually is carried out in respiratory systems. This name can cause problems; in biology the word "respiration" can mean cellular respiration or metabolism (ATP generation inside cells), however sometimes (such as here) it can also refer to breathing (which is how the word is most often used by non-biologists).
In humans and other mammals, respiratory gas exchange or ventilation is carried out by mechanisms of the lungs.
For unicellular organisms the respiratory surface is simply the cell membrane, but for large organisms it usually is carried out in respiratory systems. This name can cause problems; in biology the word "respiration" can mean cellular respiration or metabolism (ATP generation inside cells), however sometimes (such as here) it can also refer to breathing (which is how the word is most often used by non-biologists).
In humans and other mammals, respiratory gas exchange or ventilation is carried out by mechanisms of the lungs.
Emphysema is a chronic lung disease.
It is often caused by exposure to toxic chemicals or long-term exposure to tobacco smoke.
Emphysema is characterized by loss of elasticity of the lung tissue; destruction of structures supporting the alveoli; and destruction of capillaries feeding the alveoli.
The result is that the small airways collapse during expiration, leading to an obstructive form of lung disease (airflow is impeded and air is generally "trapped" in the lungs in obstructive lung diseases).
Symptoms are: shortness of breath on exertion - typically when climbing stairs or inclines (and later at rest), hyperventilation and an expanded chest.
As emphysema progresses, clubbing of the fingers may be observed, a feature of longstanding hypoxia..
Emphysema is characterized by loss of elasticity of the lung tissue; destruction of structures supporting the alveoli; and destruction of capillaries feeding the alveoli.
The result is that the small airways collapse during expiration, leading to an obstructive form of lung disease (airflow is impeded and air is generally "trapped" in the lungs in obstructive lung diseases).
Symptoms are: shortness of breath on exertion - typically when climbing stairs or inclines (and later at rest), hyperventilation and an expanded chest.
As emphysema progresses, clubbing of the fingers may be observed, a feature of longstanding hypoxia..
New Report Challenges Idea That Snuff Is A 'Safer' Substitute For Cigarettes
The review, by Stephen S. Hecht, is scheduled for the Jan. 1 issue of ACS’ Chemical Research in Toxicology.
The paper, which covers the broad range of research on cancer induced by tobacco, points out that smokeless tobacco, a known cause of oral cancer, is contaminated with levels of cancer-causing nitrosamines that are generally 1,000 times greater than those found in any other consumer product. Despite health warning labels on packages of smokeless tobacco and a ban on electronic advertising, sales of snuff have continued to increase, the paper states.
“In the past several years, a new concept has emerged,” the paper notes. “Responsible members of the tobacco control community support the idea of using ‘low nitrosamine’ moist snuff as a substitute for cigarette smoking. The rationale for this is that moist snuff is demonstrably less carcinogenic in humans, and less toxic in other ways, because it lacks the combustion products.” However, moist snuff products still contain significant levels of carcinogens, and users should stop, perhaps via use of nicotine replacement therapy, rather than switch from one risky product to another, the paper advises.
The paper, which covers the broad range of research on cancer induced by tobacco, points out that smokeless tobacco, a known cause of oral cancer, is contaminated with levels of cancer-causing nitrosamines that are generally 1,000 times greater than those found in any other consumer product. Despite health warning labels on packages of smokeless tobacco and a ban on electronic advertising, sales of snuff have continued to increase, the paper states.
“In the past several years, a new concept has emerged,” the paper notes. “Responsible members of the tobacco control community support the idea of using ‘low nitrosamine’ moist snuff as a substitute for cigarette smoking. The rationale for this is that moist snuff is demonstrably less carcinogenic in humans, and less toxic in other ways, because it lacks the combustion products.” However, moist snuff products still contain significant levels of carcinogens, and users should stop, perhaps via use of nicotine replacement therapy, rather than switch from one risky product to another, the paper advises.
Smokeless Tobacco Called 'Moist Snuff' Is Contaminated With Harmful Substances, Study Finds
A new study on the smokeless tobacco product called moist snuff -- placed between lip and gum -- has led scientists in Minnesota to urge the tobacco industry to change manufacturing practices to reduce snuff's content of carcinogens.
Why Females Live Longer Than Males: Is It Due to the Father's Sperm?
Researchers in Japan have found that female mice produced by using genetic material from two mothers but no father live significantly longer than mice with the normal mix of maternal and paternal genes. Their findings provide the first evidence that sperm genes may have a detrimental effect on lifespan in mammals.
Sunday, November 29, 2009
Bad News For Coffee Drinkers Who Get Headaches
But in findings that had “no obvious reason”, the researchers, led by Knut Hagen from NTNU’s Faculty of Medicine, also reported that low caffeine consumption was associated with a greater likelihood of chronic headaches, defined as headaches for 14 or more days each month.
The results are drawn from a large cross-sectional study of 50,483 people who answered a questionnaire about caffeine consumption and headache prevalence as a part of the Nord-Trøndelag Health Survey (HUNT 2), a county-wide health survey conducted in 1995-1997 on a wide range of health topics.
To drink or not to drink
Caffeine is the world’s most commonly consumed stimulant, and has long been known to have both positive and negative effects on headaches. For example, caffeine is a common ingredient in headache analgesics because it can help relieve headaches.
But research worldwide into the relationship between caffeine consumption and headache provides no relief to headache sufferers wondering whether they should drink more coffee or less. Some studies have shown that high caffeine consumption increases the prevalence of headaches and migraines, while other studies have shown no such relationship.
At the same time, headaches are costly to society, in work hours lost, and to individuals themselves. The World Health Organisation ranks migraine 19th in all causes of disability based on a measure called “years lived with disability”, as one example.
The issue is of particular interest in Scandinavia, because Scandinavians are heavy coffee drinkers, consuming on average about 400 mg of caffeine per day. That is roughly twice the average caffeine consumption in other European countries and in the US, and equates to roughly 4 cups of brewed coffee per day, although caffeine levels in coffee vary quite widely.
The power – and limitation -- of numbers
The HUNT study is powerful because it is large-scale, population-based and cross-sectional, but when it comes to headaches, these characteristics make it difficult to establish cause-and-effect. For example, the frequency of non-migraine headache was found by researchers to be 18 per cent more likely in individuals with high caffeine consumption (500 mg per day or more) than among those with the lowest consumption (with mean levels at 125 mg per day).
But does that mean that all that caffeine causes headaches – or that people who are more likely to suffer from headaches drink caffeinated beverages in search of relief? “Since the study is cross-sectional, it cannot be concluded that high caffeine consumption causes infrequent headache,” the researchers write.
Even more difficult is explaining why chronic headache was less likely among individuals with moderate or high caffeine consumption, the researchers said. One possibility is that caffeine consumption helps change chronic headache into infrequent headache.
Cutting back may help
But it is equally possible that chronic headache sufferers had reduced their intake of caffeine because they had experienced its headache precipitating properties – and that individuals with infrequent headaches were unaware that high caffeine might be the cause.
In an interview, Hagen said that people should consider cutting back on their coffee consumption if headaches were a problem. “People who suffer from headaches should be focused on their caffeine use, because it can be a cause of their headaches,” he said.
Soy Reduces Diabetes Risk
According to Kim, the study shows that “what we eat can have tremendous impact on health outcomes by interacting with certain genes. Recent research also suggests that diet can even change the copy number of a certain gene, leading to biological changes.”
Soy is the most common source of isoflavones in food. In experiments with mouse cells, Kim, a molecular nutrition researcher who studies how fat cells develop in the body, and colleagues, focused on daidzein, one of the two main isoflavones found in soy. Many epidemiological observations and human clinical studies have shown that adding soy to one’s diet is associated with lower diabetes risk and improved insulin sensitivity, as well as lower cardiovascular disease risk, Kim notes. However, until now the direct target tissue and molecular pathways by which soy exerts its anti-diabetic effects was not clearly understood.
Kim and colleagues at Southern Illinois University, with others at the universities of Tennessee and Florida, had earlier found that dietary isoflavones reduced the severity of diabetes in an animal model of the disease by increasing the activity of certain transcription regulators in the fat tissue. For the current study, they hypothesized that daidzein and its metabolite, equol, are part of this activation process.
They found that daidzein and equol enhanced adipocyte differentiation, or the formation of fat cells, through activation of a key transcription regulator, the same receptor that mediates the insulin-sensitizing effects of anti-diabetes drugs. Thus, daidzein and equol daidzein and equol seem to work in a similar manner as anti-diabetic drugs currently in the market. Their findings are reported in a September online version of the Journal of Nutritional Biochemistry.
“Our results suggest that soy isoflavones exert anti-diabetic effects by targeting fat cell-specific transcription factors and the downstream signaling molecules that are important for glucose uptake and thus insulin sensitivity,” Kim notes. “The new findings help us to understand the cellular mechanisms.” That is, how these biologically active compounds in soy interact to regulate and initiate metabolic and biological functions.
Results demonstrate that daidzein and equol enhance adipocyte differentiation by activating a specific receptor. The downstream responses include increased expression of three proteins, resulting in enhanced glucose uptake and insulin sensitivity.
“Although some details remain to be worked out, our data provide an additional molecular basis for the mechanism of insulin-sensitizing action by soy isoflavones,” says Kim. “These new findings help fill a critical gap between epidemiological observations and clinical studies on the anti-diabetic benefits of dietary soy.”
Future studies will extend the work to primary cultures of human cells through collaboration with researchers at Pioneer Valley Life Science Institute and Baystate Medical Center in Springfield. If replicated, studies can move on to further work in whole body systems.
Friday, November 27, 2009
Knowing Me, Myself And I
The study of self-knowledge has tended to focus on how accurate we are at determining our own internal states, such as our emotions, personality, and attitudes. However, Wilson notes that self-knowledge can be broadened to include memory, like recalling how we felt in the past, and prospection, predicting how we will feel in the future. Knowing who we were and who we will be are as important to self-knowledge as knowing who we are in the present. And while a number of researchers are conducting studies that are applicable to those various facets of self-knowledge, Wilson observes that there is not much communication between them, one reason this field is challenging to investigate.
Although it can be fairly simple to assess how people's attitudes change over time--that is, have them predict how they will feel at certain time and then actually measure their feelings at that time-- it is more difficult to measure people's current self-knowledge accurately. Some methods of acquiring accurate information on a person's feelings or their personality are to compare reports from their peers and study their nonverbal behavior. However, Wilson has "great faith in the methodological creativity" of his "fellow social psychologists" and is confident that questions raised by these types of experiments will be answered in the next few years.
Although Wilson acknowledges all the interesting findings that have come out of new technologies, such as fMRI, he cautions that those type of studies may not be very relevant to studying issues associated with self-knowledge.
There are a number of theories that aim to describe self-knowledge by a dual-process model, pitting the unconscious against the conscious. Wilson notes that these theories are pessimistic in that they view the unconscious as something that cannot be breached. However, he remarks that "self-knowledge is less a matter of careful introspection than of becoming an excellent observer of oneself."
Wilson suggests some ways that can help us learn more about ourselves, such as really attempting to be objective when considering our behaviors and trying to see ourselves through the eyes of other people. Another way of knowing ourselves better is to become more aware of findings from psychological science. Wilson concludes, "Most of us pay attention to medical findings that inform us about our bodies (e.g., that smoking tobacco is harmful), and can learn about our psychological selves in the same way."
Males Have More Personality
The study shows that in most species males show more consistent, predictable behaviours, particularly in relation to parental care, aggression and risk-taking. Females, on the other hand, are more likely to vary their behaviour. They are also more likely to respond to these traits and therefore seem to be 'choosier' about the personality of a potential mate.
The research, which is published in the journal Biological Reviews (18 November 2009) draws on several studies, dating back to 1972. It is the latest study in a growing body of research from a University of Exeter team that links gender personality differences to sexual selection.
The authors believe sexual selection may hold the key to this variation. A concept originally developed by Charles Darwin, sexual selection is the theory that evolutionary traits can be explained by competition between one sex -- usually males -- for mates and by (female) mate choice. While the physical attributes resulting from sexual selection -- from dazzling peacocks tails to over-sized antler horns -- are well known, there has been much less of a focus on the impact on personality.
Lead author Dr Wiebke Schuett of the University of Exeter says: "Our study is the first to bring together research about the impact of sexual selection on personality in humans and other animals. Our study suggests that, while males tend to exhibit more pronounced personalities, including more predictable behaviour, in a range of different contexts, females are more receptive to these traits in males. We found a surprising level of similarity across a range of species."
This paper supports research carried out by the same team, published in the journal Animal Behaviour (February 2009). The team studied the social and feeding behaviours of a population of zebra finches. They found that although the male zebra finches did not explore their environment more than the females, they were more consistent in their exploratory behaviour. The team concluded that males are more likely to be selected as mates if they are consistent in any behaviour that would be beneficial to a partnership and its offspring. This would include finding food or seeing off predators.
Dr Sasha Dall of the University of Exeter, the team leader, says: "This body of research suggests that male personality could have evolved in much the same way as signs of physical attractiveness -- to help attract a mate. Scientists have not given the role of sexual selection in shaping animal personality much consideration in the past. We hope that our work will pave the way for further research in this rather overlooked subject."
Heart Disease Found in Egyptian Mummies
Study results are appearing in the Nov. 18 issue of the Journal of the American Medical Association (JAMA) and are being presented Nov. 17 at the Scientific Session of the American Heart Association at Orlando, Fla.
"Atherosclerosis is ubiquitous among modern day humans and, despite differences in ancient and modern lifestyles, we found that it was rather common in ancient Egyptians of high socioeconomic status living as much as three millennia ago," says UC Irvine clinical professor of cardiology Dr. Gregory Thomas, a co-principal investigator on the study. "The findings suggest that we may have to look beyond modern risk factors to fully understand the disease."
The nameplate of the Pharaoh Merenptah (c. 1213-1203 BC) in the Museum of Egyptian Antiquities reads that, when he died at approximately age 60, he was afflicted with atherosclerosis, arthritis, and dental decay. Intrigued that atherosclerosis may have been widespread among ancient Egyptians, Thomas and a team of U.S. and Egyptian cardiologists, joined by experts in Egyptology and preservation, selected 20 mummies on display and in the basement of the Museum of Egyptian Antiquities for scanning on a Siemens 6 slice CT scanner during the week of Feb. 8, 2009.
The mummies underwent whole body scanning with special attention to the cardiovascular system. The researchers found that 9 of the 16 mummies who had identifiable arteries or hearts left in their bodies after the mummification process had calcification either clearly seen in the wall of the artery or in the path were the artery should have been. Some mummies had calcification in up to 6 different arteries.
Using skeletal analysis, the Egyptology and preservationist team was able to estimate the age at death for all the mummies and the names and occupations in the majority. Of the mummies who had died when they were older than 45, 7 of 8 had calcification and thus atherosclerosis while only 2 of 8 of those dying at an earlier age had calcification. Atherosclerosis did not spare women; vascular calcifications were observed in both male and female mummies.
The most ancient Egyptian afflicted with atherosclerosis was Lady Rai, who lived to an estimated age of 30 to 40 years around 1530 BC and had been the nursemaid to Queen Ahmose Nefertiri. To put this in context, Lady Rai lived about 300 years prior to the time of Moses and 200 prior to King Tutankhamun (Tut).
In those mummies whose identities could be determined, all were of high socioeconomic status, generally serving in the court of the Pharaoh or as priests or priestess. While the diet of any one mummy could not be determined, eating meat in the form of cattle, ducks and geese was not uncommon during these times.
"While we do not know whether atherosclerosis caused the demise of any of the mummies in the study, we can confirm that the disease was present in many," Thomas says.
In addition to Thomas, Dr. Adel Allam of the Al Azhar Medical School in Cairo, Egypt, is the study's co-principal investigator. Dr. Randall Thompson of the Mid America Heart Institute in Kansas City, Mo.; Dr. L. Samuel Wann of the Wisconsin Heart Hospital in Milwaukee; and Dr. Michael Miyamoto of UC San Diego also contributed to the JAMA report.
The authors express their appreciation to Zahi Hawass, secretary general of the Supreme Council of Antiquities, for allowing them to scan these mummies and perform this investigation.
Yoga Boosts Heart Health
The autonomic nervous system regulates the heart rate through two routes -- the sympathetic and parasympathetic nervous systems. The former causes the heart rate to rise, while, the parasympathetic slows it. When working well together, the two ensure that the heart rate is steady but ready to respond to changes caused by eating, the fight or flight response, or arousal.
The ongoing variation of heart rate is known as heart rate variability (HRV), which refers to the beat-to-beat changes in heart rate. In healthy individuals HRV is high whereas cardiac abnormalities lead to a low HRV.
Now, Ramesh Kumar Sunkaria, Vinod Kumar, and Suresh Chandra Saxena of the Electrical Engineering Department, at the Indian Institute of Technology in Roorkee, in Uttrakhand, India, have evaluated two small groups of men in order to see whether yoga practitioners can improve heart health. Anecdotal evidence would suggest that yoga practice may improve health through breathing exercises, stretching, postures, relaxation, and meditation.
The team analyzed the HRV "spectra" of the electrocardiograms (ECG) of forty two healthy male volunteers who are non-yogic practitioners, and forty two who are experienced practitioners, all volunteers were aged between 18 and 48 years.
The spectral analysis of HRV is, the team says, an important tool in exploring heart health and the mechanisms of heart rate regulation. The power represented by various spectral bands in short-term HRV are indicative of how well the heart responds to changes in the body controlled by the sympathetic and the parasympathetic nervous systems.
The team explains that very low frequency (VLF) variations in the spectra are linked to the body's internal temperature control. Low frequency peaks are associated with the sympathetic control and high frequency with parasympathetic control.
The team concludes that in their preliminary study of 84 volunteers, there is strengthening of parasympathetic (vagal) control in subjects who regularly practice yoga, which is indicative of better autonomic control over heart rate and so a healthier heart.
Moderate-to-Heavy Exercise May Reduce Risk of Stroke for Men
Men who regularly take part in moderate-to-heavy intensity exercise such as jogging, tennis or swimming may be less likely to have a stroke than people who get no exercise or only light exercise, such as walking, golfing, or bowling, according to a study published in the November 24, 2009, print issue of Neurology®, the medical journal of the American Academy of Neurology.
However, exercise did not have a protective effect against stroke for women. Women who took part in moderate-to-heavy intensity exercise did not have a reduced risk of stroke.
The study involved 3,298 people living in northern Manhattan, NY, with an average age of 69 who were followed for about nine years. During that time, there were 238 strokes. A total of 41 percent of the participants reported that they participated in no physical activity. Twenty percent regularly participated in moderate-to-heavy intensity activities.
Men who participated in moderate-to-heavy intensity activities were 63 percent less likely to have a stroke than people with no physical activity. The baseline risk of ischemic stroke over five years in the entire group was 4.3 percent; among those with moderate-to-heavy intensity activities the risk was 2.7 percent, and among those with no activity it was 4.6 percent.
"Taking part in moderate-to-heavy intensity physical activity may be an important factor in preventing stroke," said study author Joshua Z. Willey, MD, of Columbia University Medical Center and New York Presbyterian Hospital at Columbia. Willey is also a member of the American Academy of Neurology. "A large percentage of the participants were not taking part in any physical activities. This may be true of many elderly people who live in cities. Identifying ways to improve physical activity among these people may be a key goal for public health."
These results are contrary to some other studies that found that even light intensity physical activity reduced the risk of stroke. Willey said the number of participants may not have been large enough to detect subtle differences in the group that took part in only light physical activity.
Stroke is the leading cause of disability and the third-leading cause of death in the United States.
The study was supported by the National Institutes of Health
However, exercise did not have a protective effect against stroke for women. Women who took part in moderate-to-heavy intensity exercise did not have a reduced risk of stroke.
The study involved 3,298 people living in northern Manhattan, NY, with an average age of 69 who were followed for about nine years. During that time, there were 238 strokes. A total of 41 percent of the participants reported that they participated in no physical activity. Twenty percent regularly participated in moderate-to-heavy intensity activities.
Men who participated in moderate-to-heavy intensity activities were 63 percent less likely to have a stroke than people with no physical activity. The baseline risk of ischemic stroke over five years in the entire group was 4.3 percent; among those with moderate-to-heavy intensity activities the risk was 2.7 percent, and among those with no activity it was 4.6 percent.
"Taking part in moderate-to-heavy intensity physical activity may be an important factor in preventing stroke," said study author Joshua Z. Willey, MD, of Columbia University Medical Center and New York Presbyterian Hospital at Columbia. Willey is also a member of the American Academy of Neurology. "A large percentage of the participants were not taking part in any physical activities. This may be true of many elderly people who live in cities. Identifying ways to improve physical activity among these people may be a key goal for public health."
Stroke is the leading cause of disability and the third-leading cause of death in the United States.
The study was supported by the National Institutes of Health
Wednesday, November 25, 2009
S k i n a n d s u n
How does the sun affect the skin?
Sunlight is an essential source of energy and is vitally important to life. However, absorption of
incident solar energy by components of the skin causes premature skin aging, known as photoaging
(Berneburg, 2000; Hadshiew, 2000). Photoaged skin displays textural and pigmentary changes as
well as prominent alterations in the organization of connective tissue (breakdown of collagen and
elastin fibers) and cell death. The skin becomes wrinkled, less elastic, dry and rough, and uneven in
pigmentation.
What are the differences between UVA and UVB rays?
Most of the photobiological effects of the sun, including sunburn, sun tanning, and immunosuppression,
are attributed to UVB rays (290-320 nm). However, UVA rays (320-400 nm) can cause
more significant damage to the skin. Because they permeate more deeply into the dermal matrix
than UVB rays, UVA rays can induce long-lasting skin lesions and contribute to the formation of free
radicals (these are involved in the alteration of all skin compounds and in skin aging). UVA rays can
thus cause irreversible skin alterations and induce skin cancer (Mariéthoz, 1998).
What can you do to protect your skin?
The best protection against photoaging is avoidance of sunlight, particularly when it is at its strongest
(during the summer and in between 11 am and 3 pm). Remember to always wear sun protection, even
on winter days. Your sunscreen should block out both UVA and UVB rays and be SPF (Sun Protection
Factor) 30 or above. Clothes are also an effective means of protection against the sun
Sunlight is an essential source of energy and is vitally important to life. However, absorption of
incident solar energy by components of the skin causes premature skin aging, known as photoaging
(Berneburg, 2000; Hadshiew, 2000). Photoaged skin displays textural and pigmentary changes as
well as prominent alterations in the organization of connective tissue (breakdown of collagen and
elastin fibers) and cell death. The skin becomes wrinkled, less elastic, dry and rough, and uneven in
pigmentation.
What are the differences between UVA and UVB rays?
Most of the photobiological effects of the sun, including sunburn, sun tanning, and immunosuppression,
are attributed to UVB rays (290-320 nm). However, UVA rays (320-400 nm) can cause
more significant damage to the skin. Because they permeate more deeply into the dermal matrix
than UVB rays, UVA rays can induce long-lasting skin lesions and contribute to the formation of free
radicals (these are involved in the alteration of all skin compounds and in skin aging). UVA rays can
thus cause irreversible skin alterations and induce skin cancer (Mariéthoz, 1998).
What can you do to protect your skin?
The best protection against photoaging is avoidance of sunlight, particularly when it is at its strongest
(during the summer and in between 11 am and 3 pm). Remember to always wear sun protection, even
on winter days. Your sunscreen should block out both UVA and UVB rays and be SPF (Sun Protection
Factor) 30 or above. Clothes are also an effective means of protection against the sun
Monday, November 23, 2009
Heavy, Daily Drinking Increases Risk Of High-Grade Prostate Cancer; Makes Preventive Drug Ineffective
Current research is inconclusive regarding the relationship between alcohol consumption and prostate cancer risk. Researchers led by Zhihong Gong Ph.D. of the University of California San Francisco, examined the associations of total alcohol, type of alcoholic beverage, and drinking pattern with risks of total, low- and high-grade prostate cancer.
They used data from more than 10,000 men participating in the Prostate Cancer Prevention Trial (PCPT). They found participants who reported heavy alcohol consumption (≥50 g alcohol/day) and regular heavy drinking (≥4 drinks/day on ≥5 days per week) were twice as likely or more to be diagnosed with high-grade prostate cancer (RR: 2.01, and 2.17, respectively). Less heavy drinking was not associated with risk.
They also compared drinking patterns with treatment outcome among men enrolled on this placebo-controlled trial of the drug finasteride. They found finasteride's ability to lower prostate cancer risk was blocked in men drinking <50g alcohol per day.
They conclude heavy, daily drinking increases the risk of high-grade prostate cancer and that heavy drinking made finasteride ineffective for reducing prostate cancer risk.
They used data from more than 10,000 men participating in the Prostate Cancer Prevention Trial (PCPT). They found participants who reported heavy alcohol consumption (≥50 g alcohol/day) and regular heavy drinking (≥4 drinks/day on ≥5 days per week) were twice as likely or more to be diagnosed with high-grade prostate cancer (RR: 2.01, and 2.17, respectively). Less heavy drinking was not associated with risk.
They also compared drinking patterns with treatment outcome among men enrolled on this placebo-controlled trial of the drug finasteride. They found finasteride's ability to lower prostate cancer risk was blocked in men drinking <50g alcohol per day.
They conclude heavy, daily drinking increases the risk of high-grade prostate cancer and that heavy drinking made finasteride ineffective for reducing prostate cancer risk.
Men with lower cholesterol are less likely than those with higher levels to develop high-grade prostate cancer -- an aggressive form of the disease with a poorer prognosis
In a prospective study of more than 5,000 U.S. men, epidemiologists say they now have evidence that having lower levels of heart-clogging fat may cut a man's risk of this form of cancer by nearly 60 percent.
"For many reasons, we know that it's good to have a cholesterol level within the normal range," says Elizabeth Platz, Sc.D., M.P.H., associate professor at the Johns Hopkins Bloomberg School of Public Health and co-director of the cancer prevention and control program at the Johns Hopkins Kimmel Cancer Center. "Now, we have more evidence that among the benefits of low cholesterol may be a lower risk for potentially deadly prostate cancers."
Normal range is defined as less than 200 mg/dL (milligrams per deciliter of blood) of total cholesterol.
Platz and her colleagues found similar results in a study first published in 2008, and in 2006, she linked use of cholesterol-lowering statin drugs to lower risk of advanced prostate cancer.
For the current study, Platz, members of the Southwest Oncology Group, and other collaborators analyzed data from 5,586 men aged 55 and older enrolled in the Prostate Cancer Prevention Trial from 1993 to 1996. Some 1,251 men were diagnosed with prostate cancer during the study period.
Men with cholesterol levels lower than 200 mg/dL had a 59 percent lower risk of developing high-grade prostate cancers, which tend to grow and spread rapidly. High-grade cancers are identified by a pathological ranking called the Gleason score. Scores at the highest end of the scale, between eight and 10, indicate cancers considered the most worrisome to pathologists who examine samples of the diseased prostate under the microscope.
In Platz's study, cholesterol levels had no significant effect on the entire spectrum of prostate cancer incidence, only those that were high-grade, she says.
Platz cautions that, while the group took into account factors that could bias the results, such as smoking history, weight, family history of prostate cancer, and dietary cholesterol, other things could have affected their results. One example is whether men in the study were taking cholesterol-lowering drugs at the time of the blood collections, a data point the researchers expect to analyze soon.
Results of the current study are expected to be published online Nov. 3 in the journal Cancer Epidemiology, Biomarkers & Prevention. Also in the journal is an accompanying paper from the National Cancer Institute showing that lower cholesterol in men conferred a 15 percent decrease in overall cancer cases.
"Cholesterol may affect cancer cells at a level where it influences key signaling pathways controlling cell survival," says Platz. "Cancer cells use these survival pathways to evade the normal cycle of cell life and death."
She says that targeting cholesterol metabolism may be one route to treating and preventing the disease, but this remains to be tested.
Funding for the study was provided by the National Cancer Institute.
Authors of the study include Cathee Till, Phyllis J. Goodman, Marian L. Neuhouser and Alan R. Kristal from the Fred Hutchinson Cancer Research Center; Howard L. Parnes, William D. Figg, and Demetrius Albanes from the National Cancer Institute; Eric A. Klein from the Cleveland Clinic; and Ian M. Thompson Jr., from the University of Texas Health Sciences Center.
"For many reasons, we know that it's good to have a cholesterol level within the normal range," says Elizabeth Platz, Sc.D., M.P.H., associate professor at the Johns Hopkins Bloomberg School of Public Health and co-director of the cancer prevention and control program at the Johns Hopkins Kimmel Cancer Center. "Now, we have more evidence that among the benefits of low cholesterol may be a lower risk for potentially deadly prostate cancers."
Normal range is defined as less than 200 mg/dL (milligrams per deciliter of blood) of total cholesterol.
Platz and her colleagues found similar results in a study first published in 2008, and in 2006, she linked use of cholesterol-lowering statin drugs to lower risk of advanced prostate cancer.
For the current study, Platz, members of the Southwest Oncology Group, and other collaborators analyzed data from 5,586 men aged 55 and older enrolled in the Prostate Cancer Prevention Trial from 1993 to 1996. Some 1,251 men were diagnosed with prostate cancer during the study period.
Men with cholesterol levels lower than 200 mg/dL had a 59 percent lower risk of developing high-grade prostate cancers, which tend to grow and spread rapidly. High-grade cancers are identified by a pathological ranking called the Gleason score. Scores at the highest end of the scale, between eight and 10, indicate cancers considered the most worrisome to pathologists who examine samples of the diseased prostate under the microscope.
In Platz's study, cholesterol levels had no significant effect on the entire spectrum of prostate cancer incidence, only those that were high-grade, she says.
Platz cautions that, while the group took into account factors that could bias the results, such as smoking history, weight, family history of prostate cancer, and dietary cholesterol, other things could have affected their results. One example is whether men in the study were taking cholesterol-lowering drugs at the time of the blood collections, a data point the researchers expect to analyze soon.
Results of the current study are expected to be published online Nov. 3 in the journal Cancer Epidemiology, Biomarkers & Prevention. Also in the journal is an accompanying paper from the National Cancer Institute showing that lower cholesterol in men conferred a 15 percent decrease in overall cancer cases.
"Cholesterol may affect cancer cells at a level where it influences key signaling pathways controlling cell survival," says Platz. "Cancer cells use these survival pathways to evade the normal cycle of cell life and death."
She says that targeting cholesterol metabolism may be one route to treating and preventing the disease, but this remains to be tested.
Funding for the study was provided by the National Cancer Institute.
Authors of the study include Cathee Till, Phyllis J. Goodman, Marian L. Neuhouser and Alan R. Kristal from the Fred Hutchinson Cancer Research Center; Howard L. Parnes, William D. Figg, and Demetrius Albanes from the National Cancer Institute; Eric A. Klein from the Cleveland Clinic; and Ian M. Thompson Jr., from the University of Texas Health Sciences Center.
Friday, November 20, 2009
Sunday, November 15, 2009
Economic Stress—How Bad Is It Really?
Before the financial collapse, Dr. Jonathan Whiteson says his patients made predictable small talk. "It used to be, 'How are the children? Where did you go on vacation?'" he recalls."Now," he says, "they come in with a [newspaper] tucked under their arm and say, 'Did you see this?'" Usually they're pointing to a story about the market's dismal fortunes or the fallout of yet another Ponzi scheme.
Whiteson, director of cardiac and pulmonary wellness and rehabilitation at New York University's Langone Medical Center, says the change in tone has been accompanied by complaints about ailments small and large, including chest pain, gastrointestinal distress and muscle aches.
That's unsurprising given that scientific research has long demonstrated a link between poor health outcomes and declining employment and gross domestic product. Since the recession began in December 2007, the economy has shed 5.1 million jobs and the unemployment rate has reached 8.5 percent. Meanwhile, U.S. GDP decreased at an annual rate of 6.3 percent in the fourth quarter of 2008.
And since the economy began quickly unraveling last fall, there have been numerous reports about how this dynamic is playing out in the current recession: Americans are sleeping less, seeing doctors less frequently and slowing prescription drug refills.
But some reports may be exaggerating how bad the recession has been for Americans' health.
By the numbers
To be fair, various polls and surveys have accurately tracked some of the effects. In March, the National Sleep Foundation reported that more than a quarter of 1,000 survey participants were sleeping less because of the economy.
The recession has also forced Americans to skimp on health care. In a February telephone poll of 1,200 adults conducted by the nonprofit Kaiser Family Foundation, 53 percent of respondents said they cut back on health care costs by avoiding doctor's visits, skipping dental check-ups and not filling prescriptions, among other strategies.
The American Hospital Association, a national trade organization, recently reported that total visits to 650 hospitals across the country were down in the fourth quarter of 2008 compared to the previous year, with nearly 3 percent fewer visits to the emergency room and 2 percent fewer patient surgeries. The sample is not nationally representative, but is still considered a leading indicator of hospital performance.
Despite such research, it remains challenging to gauge what is happening across the nation. That's because the government rarely collects data about health outcomes in real-time. The Centers for Disease Control and Prevention, for example, surveys the public about contraceptive use once over a several-year period and those figures aren't released until a year or two later. As such, it often requires rigorous statistical and epidemiological analysis to link a single negative health outcome to the economy.
Even some major insurers are reluctant to discuss the situation. UnitedHealth Group and Aetna declined to comment on how the recession might be reducing the frequency of treatments and procedures, citing insufficient data on usage trends in the past six months.
Perception vs. reality
The dearth of statistics may explain why some are turning to individual providers for answers about what's happening to patients nationwide.
The dearth of statistics may explain why some are turning to individual providers for answers about what's happening to patients nationwide.
At his clinic, Dr. Whiteson has noticed that patients more frequently complain of shortness of breath, fatigue, dizziness and palpitations. They seem to be experiencing sexual dysfunction more often and report drinking more frequently.
But extrapolating such observations beyond one practice can be deceiving. Craig Wolf, president and CEO of the Wine and Spirits Wholesalers of America, Inc., says that per capita alcohol consumption has remained flat for the past 30 years—even in the past six months.
Even during deep recessions of the '70s and '80s, Americans annually drank about 2.7 gallons of alcohol per capita, a figure that has never decreased more than a half-gallon in the decades since.
Other potentially misleading anecdotes have popped up recently. A report by the Associated Press found that some regional and state health clinics and hospitals had seen a significant increase in the number of local abortions and vasectomies since last year. Last month the Washington Times reported that dentists nationwide had noticed an uptick in the number of teeth grinding cases since 2007.
But as it turns out, neither trend could be confirmed by outside sources. Planned Parenthood and the American Dental Association both lacked national data to verify the anecdotal reports.
"It's reasonable and it's plausible," says Dr. Matthew Messina, a consumer adviser for the ADA, "but it still is an urban myth."
Ted Joyce, a professor of economics at Baruch College at the City University of New York, says that there's little evidence that abortions follow business cycles. Verifying this would require comparing monthly unemployment data to monthly abortion rates, which is not collected by nonprofit organizations or the government. Looking at the raw data—abortions stayed level at 1.6 million annually throughout the '80s—doesn't help establish a pattern, either.
Skeptics might want to consult research pioneered by Dr. Harvey Brenner, a professor of public health at the University of North Texas Health Science Center and at John Hopkins University's Bloomberg School of Public Health, which has shown a correlation between economic downturns and a rise in suicides and cardiovascular mortality.
This has been proven in "sharp and complete statistical studies," says Brenner, which "all lead to a fairly strong case that major disturbances to peoples' economic lives make a real difference in life expectancy."
That's partly because high-stress events elicit an immunological response from the body, leaving it vulnerable to everything from the common cold to a heart attack. Couple the stress response with the cutback in preventive care prompted by the floundering economy, and personal health suffers.
But even Dr. Whiteson, who is certain the economy is negatively affecting his patients' health, is struggling to separate persistent symptoms from ones temporarily brought on by stress.
"It's becoming an increasing challenge to work out what's real and what's not real," he says
What gives you that feel-good feeling
Are we hard-wired to be good people? Is helping our fellow man a natural instinct of our kind?
It's inviting to believe we share species-wide morality when we see U.N. rations drop into a destitute village or watch a rescue worker pull a toddler from a well. Altruism needn't come on such a grandiose scale, either; we feel the same swell of pride and humility from everyday overtures like shoveling the neighbor's walk or offering directions to a lost stranger.
Granted, we don't live it 24/7. Anyone who's spent more than five minutes on the phone with the cable company's customer service line has danced with his darker demons. But we know when we're morally and ethically on track.
It's inviting to believe we share species-wide morality when we see U.N. rations drop into a destitute village or watch a rescue worker pull a toddler from a well. Altruism needn't come on such a grandiose scale, either; we feel the same swell of pride and humility from everyday overtures like shoveling the neighbor's walk or offering directions to a lost stranger.
Granted, we don't live it 24/7. Anyone who's spent more than five minutes on the phone with the cable company's customer service line has danced with his darker demons. But we know when we're morally and ethically on track.
Ethical behavior's effect on the brain
We know because the brain tells us so in its strange chemical language. Research in the young field of social neuroscience has revealed that the brain is activated in response to compassion and ethical behavior.
Several studies have focused on the brain's reward circuit to try to connect the dots between neurological function, emotion and ethics. The reward circuit is an interacting group of brain areas including the ventral striatum and ventromedial prefrontal cortex (a small region behind the forehead), and it's understood to be a hub of the brain's emotional network.
It's here that we manage reason and emotions like compassion and shame, and where we process pleasure in response to stimuli like an attractive face or a big bite of chocolate. Over the past two years, studies have linked the reward circuit to altruism, the perception of justice, and a sense of fairness.
Another study by world-class neuroscientists suggests the same area of the brain is engaged in deeper moral judgments. Working with 30 subjects, researchers posed classic morality scenarios such as: If one person in a life raft had to be thrown over so that several others could live, could you toss her over?
Each of the six subjects who had suffered injuries to the prefrontal cortex—and only those six—responded without reservation that they were willing to harm one individual to save themselves and the others.
"In those circumstances most people without this specific brain damage will be torn," said one author of the study. "But these particular subjects seem to lack that conflict." The research has been noted for linking the block of emotions with a failure of moral judgment.
Studies on oxytocin (more widely recognized for its role in childbirth and parent/child bonding) also have linked brain activity with higher moral functions. Acts of selflessness, the touch of another's hand, the glance of a mother into her newborn baby's eyes—all are known to trigger release of the hormone, which in turn promotes the release of dopamine. The flooding of dopamine into the brain's reward center elicits that warm surge of satisfaction we get from doing good things or being in the company of people we love and trust. It's the pleasure response.
Soul stirring
While these findings represent some terrific leaps in neuroscience, they also stir up some troubling questions. People get uneasy when science rubs up against philosophy or, heaven forbid, theology.
We've taken it on good scientific authority that all stimuli and responses course through the brain. Yet we still credit our loftier inclinations to the mind, the soul, or even to the heart. We say music is "good for the soul" or that a child's smile "fills the heart" with joy. No one ascribes a vision of peace and brotherhood to their ventromedial prefrontal cortex. No romantic wants to equate a flow of emotion with a flow of oxytocin.
While this all may sound like groundwork for an argument that we are a robotic and soulless race, science is not laying claim to the impulses at the origin of ethical thought. Neither has it been able to find a clear evolutionary advantage for all of these brain reactions, suggesting humans are wired for more than survival of the species.
This line of study does approach an understanding of how humans process moral and ethical choices. Structures and chemicals in the brain help set the magnet of our moral compass. But so too do we feel within ourselves something greater than ourselves.
Brain loves the good kind and the bad
A friend offers you a smoke while you're tailgating at the game. You have one every now and then, and you're not hooked, so sure, thanks. Besides, it does look good with your drink. This, my friend, is your brain battling a bad habit—and losing. As we continually perform a behavior—smoking socially, say, or texting while driving—neural pathways in our brains form new patterns, according to a recent MIT review. Once the prompt arrives, your brain shifts into autopilot. "Situational cues bring out habits that are deeply embedded," says Ellen Peters, Ph.D., who studies risk perceptions at Decision Research, a psychological research firm in Eugene, Ore. "When that habit surfaces, it's hard not to let it overcome you." The problem, of course, is that these proclivities can endanger your health. So follow our guide to rid yourself, once and for all, of a few distinctly unhealthy habits.
A quick drag every now and again ...
While regular smokers have a chemical component fueling their addiction, people who smoke only occasionally succumb mainly to social and environmental triggers. "The most powerful prompt is often being around other people who are smoking or drinking," says Michael Fiore, M.D., director of the University of Wisconsin Center for Tobacco Research and Intervention. In stressful situations, a cigarette can put you at ease: 10 minutes after you take a puff, your brain releases a surge of dopamine, a neurotransmitter that can make you feel relaxed and happy. (Want to boost your mood without cigarettes or drugs?
While regular smokers have a chemical component fueling their addiction, people who smoke only occasionally succumb mainly to social and environmental triggers. "The most powerful prompt is often being around other people who are smoking or drinking," says Michael Fiore, M.D., director of the University of Wisconsin Center for Tobacco Research and Intervention. In stressful situations, a cigarette can put you at ease: 10 minutes after you take a puff, your brain releases a surge of dopamine, a neurotransmitter that can make you feel relaxed and happy. (Want to boost your mood without cigarettes or drugs?
Why it's bad: Lighting up even a few times a week is still poisoning yourself. "There's no lower limit of exposure to tobacco smoke that is safe. Period," says Richard D. Hurt, M.D., director of the Mayo Clinic Nicotine Dependence Center. In fact, a single cigarette can almost instantly injure the inner walls of your blood vessels. That damage can lead to heart disease and blood clots. Looming in the background, of course, is also the risk of developing a full-blown addiction. Some research suggests that about a quarter of "occasional" smokers go full-time.
Break the habit: When you can't steer clear of the smokestacks, benign substitutes can work wonders, Dr. Hurt says. For instance, grab a drink stirrer and hold it between your fingers like a cigarette. Set it between your lips while you take out your wallet or phone. This keeps your mouth and hands busy. And carry nicotine gum or lozenges—these can mimic the effects of nicotine from cigarettes, Dr. Fiore says.
Evenings in front of the tube ...
Grabbing some snacks and firing up the plasma after work is okay once or twice a week. But every night? Yes, bad habit. "People who are under high levels of stress and who may not have a large network of friends are prone to isolating themselves after work," says Leonard Jason, Ph.D., a DePaul University psychologist who studies the challenges of breaking bad habits. "Eventually, it becomes their default."
Why it's bad: Slumming it on the couch plays havoc with your body and your brain. For one thing, people can consume up to 71 percent more food while they're glued to the tube, so it's no surprise that watching more than 19 hours a week increases your odds of being overweight by 97 percent, according to a 2007 Belgian study. And researchers at Case Western Reserve University found that for every hour of TV beyond 80 minutes that you watch daily, your risk of developing Alzheimer's increases by a whopping 30 percent.
Grabbing some snacks and firing up the plasma after work is okay once or twice a week. But every night? Yes, bad habit. "People who are under high levels of stress and who may not have a large network of friends are prone to isolating themselves after work," says Leonard Jason, Ph.D., a DePaul University psychologist who studies the challenges of breaking bad habits. "Eventually, it becomes their default."
Why it's bad: Slumming it on the couch plays havoc with your body and your brain. For one thing, people can consume up to 71 percent more food while they're glued to the tube, so it's no surprise that watching more than 19 hours a week increases your odds of being overweight by 97 percent, according to a 2007 Belgian study. And researchers at Case Western Reserve University found that for every hour of TV beyond 80 minutes that you watch daily, your risk of developing Alzheimer's increases by a whopping 30 percent.
Break the habit: If you have a digital video recorder, use it to record shows, and simply start your descent to bedtime later in the evening, Jason suggests. Zipping through the commercials can cut about half an hour off every 2 hours of couch time. Then, at least three times a week, make afterwork plans that specifically involve people—meet friends for dinner, or join a recreational sports team. "Finding alternatives that you can do with others helps reduce passive TV viewing," Jason says. How about taking her out? But not just for dinner and a movie—plan one of these unforgettable adventures for a date like she's never gone on before.
Your caffeine drip ...
The human body embraces some vices with gusto, effectively launching lifelong habits by punishing you for skipping even a single hit. That's caffeine's MO. When a caffeine fanatic doesn't get that fix, bloodflow in the brain spikes, according to a 2009 study in Psychopharmacology. This expansion of blood vessels results in a headache, while you suffer from symptoms such as fatigue and grumpiness. To avoid this, you visit the vending machines or the office java pot. (Makes us wonder: Why can't fruits and vegetables hook us like this?)
Why it's bad: A constant infusion of caffeine can set your nerves on edge. "High daily caffeine intake may decrease hand steadiness and increase anxiety," says Russell Keast, Ph.D., a caffeine-consumption researcher at the School of Exercise and Nutrition Sciences at Deakin University, in Australia. Then there's a 2007 study from Dartmouth medical school, which found that people who consumed 400 milligrams of caffeine a day (about four 8-ounce cups of coffee) for a week experienced a 35 percent decrease in insulin sensitivity, which may increase the risk of diabetes. And if you commonly drink any of the worst frozen coffee drinks in America, you could be slurping down a day's worth of calories in minutes.
The human body embraces some vices with gusto, effectively launching lifelong habits by punishing you for skipping even a single hit. That's caffeine's MO. When a caffeine fanatic doesn't get that fix, bloodflow in the brain spikes, according to a 2009 study in Psychopharmacology. This expansion of blood vessels results in a headache, while you suffer from symptoms such as fatigue and grumpiness. To avoid this, you visit the vending machines or the office java pot. (Makes us wonder: Why can't fruits and vegetables hook us like this?)
Why it's bad: A constant infusion of caffeine can set your nerves on edge. "High daily caffeine intake may decrease hand steadiness and increase anxiety," says Russell Keast, Ph.D., a caffeine-consumption researcher at the School of Exercise and Nutrition Sciences at Deakin University, in Australia. Then there's a 2007 study from Dartmouth medical school, which found that people who consumed 400 milligrams of caffeine a day (about four 8-ounce cups of coffee) for a week experienced a 35 percent decrease in insulin sensitivity, which may increase the risk of diabetes. And if you commonly drink any of the worst frozen coffee drinks in America, you could be slurping down a day's worth of calories in minutes.
Break the habit: Start by keeping a food diary for a few days to identify all the sources of caffeine in your diet—soda, coffee, tea, energy drinks—and tally the total milligrams you're consuming, says Chad Reissig, Ph.D., a researcher at Johns Hopkins University who studies the behavioral effects of caffeine. (Consult beverage manufacturer Web sites for the actual amounts.) Then reduce your caffeine intake by about 10 percent. This could be as simple as drinking a 12-ounce can of cola instead of the 20-ounce bottle. "You can also mix decaf with your cup of full-strength coffee, and slowly increase the ratio," says Reissig. Keep dialing back by 10 percent every few days until your craving subsides. The gradual reduction should minimize fatigue and headaches, but plan for them anyway: Go to bed earlier to keep drowsiness at bay, Reissig says, and carry Advil or Tylenol to treat brain pain.
Cranking the tunes ...
This habit sneaks up on you: You listen to your music through your headphones at a higher volume than you should a few times, and your ears become accustomed to it. Then you play it at that level all the time. Eventually, you max out the volume controls on the iPod. "It's possible to quickly adapt and become accustomed to louder and louder sounds without realizing it," says Robert Fifer, Au.D., the director of audiology and speech language pathology at the University of Miami's Mailman Center for Child Development.
Cranking the tunes ...
This habit sneaks up on you: You listen to your music through your headphones at a higher volume than you should a few times, and your ears become accustomed to it. Then you play it at that level all the time. Eventually, you max out the volume controls on the iPod. "It's possible to quickly adapt and become accustomed to louder and louder sounds without realizing it," says Robert Fifer, Au.D., the director of audiology and speech language pathology at the University of Miami's Mailman Center for Child Development.
Why it's bad: Blasting Nickelback at full volume through earbuds for long intervals can cause permanent hearing damage, because your body lacks a self-defense mechanism for loud noise. While you won't feel pain in your ears until the volume exceeds 120 decibels, the damage can begin earlier than that. The cells in your inner ear that process sound begin working overtime to keep up with the onslaught, and eventually die off under stress, says Dr. Fifer. The fewer of these cells you have, the more difficult it becomes to hear soft sounds. You may also experience a constant ringing in your ears, called tinnitus.
Break the habit: You have to retrain your brain to perceive lower volume levels as normal and to automatically tune out background noise. Start by turning down the volume on your iPod or car stereo until you can hear other people talking to you—they shouldn't have to shout. "If you force yourself to listen to music at a lower level, your brain will begin to perceive it as normal after about a week," says Catherine Palmer, Ph.D., the director of audiology at the University of Pittsburgh Medical Center Eye & Ear Institute. Also, think about using Loud Enough earphones ($40, loudenough.com), which reduce your music player's maximum volume by up to 20 decibels. And for ways to improve your eyesight, posture, and more with these 17 problems you can fix right now.
Talking and texting while driving ...
We keep doing this because while we intuitively know that the combination is unsafe, we assume nothing would ever happen to us. "If you do it once and nothing happens, your experience tells you that it's OK," says Peters. "Those repeated safe experiences build up a sense of invulnerability."
Why it's bad: The hard reality is that our habit of talking and texting while driving, which springs from our still-bubbling enthusiasm for our mobile devices, conflicts directly with proof that we suck at it. Look no further than the September 2008 train crash in Los Angeles that killed 25 people; a commuter train's engineer had just sent a text message before the collision with a freight train. Even having a hands-free cellphone conversation while driving slows your reaction time by more than 20 percent, a French study found.
Break the habit: Switching your cellphone ringer to silent when you step in the car is an easy, effective fix. But many people forget to do that, or they forget to turn the ringer up again, so a better strategy is to train yourself to not want to pick up the phone. "You can teach yourself to have a negative emotional association with cellphone use while driving," Peters says. When your phone rings or beeps with a new text message, visualize what could happen if your attention is distracted—picture yourself plowing into the car ahead of you. Be graphic about it. Then imagine the effect that an accident would have on your family and on the family of the person you hit. Over time, you'll start associating the ringing cellphone with a crash, and you'll have less desire to answer it.
Break the habit: You have to retrain your brain to perceive lower volume levels as normal and to automatically tune out background noise. Start by turning down the volume on your iPod or car stereo until you can hear other people talking to you—they shouldn't have to shout. "If you force yourself to listen to music at a lower level, your brain will begin to perceive it as normal after about a week," says Catherine Palmer, Ph.D., the director of audiology at the University of Pittsburgh Medical Center Eye & Ear Institute. Also, think about using Loud Enough earphones ($40, loudenough.com), which reduce your music player's maximum volume by up to 20 decibels. And for ways to improve your eyesight, posture, and more with these 17 problems you can fix right now.
Talking and texting while driving ...
We keep doing this because while we intuitively know that the combination is unsafe, we assume nothing would ever happen to us. "If you do it once and nothing happens, your experience tells you that it's OK," says Peters. "Those repeated safe experiences build up a sense of invulnerability."
Why it's bad: The hard reality is that our habit of talking and texting while driving, which springs from our still-bubbling enthusiasm for our mobile devices, conflicts directly with proof that we suck at it. Look no further than the September 2008 train crash in Los Angeles that killed 25 people; a commuter train's engineer had just sent a text message before the collision with a freight train. Even having a hands-free cellphone conversation while driving slows your reaction time by more than 20 percent, a French study found.
Break the habit: Switching your cellphone ringer to silent when you step in the car is an easy, effective fix. But many people forget to do that, or they forget to turn the ringer up again, so a better strategy is to train yourself to not want to pick up the phone. "You can teach yourself to have a negative emotional association with cellphone use while driving," Peters says. When your phone rings or beeps with a new text message, visualize what could happen if your attention is distracted—picture yourself plowing into the car ahead of you. Be graphic about it. Then imagine the effect that an accident would have on your family and on the family of the person you hit. Over time, you'll start associating the ringing cellphone with a crash, and you'll have less desire to answer it.
Monday, November 9, 2009
Regulating Emotion After Experiencing A Sexual Assault
After exposure to extreme life stresses, what distinguishes the individuals who do and do not develop posttraumatic stress disorder (PTSD)? A new study, published in the October 1st issue
suggests that it has something to do with the way that we control the activity of the prefrontal cortex, a brain region thought to orchestrate our thoughts and actions.
Researchers at the Mount Sinai School of Medicine examined women who had been the victims of violent sexual assault, some of whom developed PTSD and others who did not develop any serious emotional symptoms afterwards. Using a brain imaging technique, they evaluated the ability of these women to voluntarily modify their own responses to unpleasant emotional stimuli and found that it was the trauma history itself, not how well they endured this sort of trauma, that influenced their ability to dampen subsequent emotional responses.
Surprisingly, however, the ability of the subjects to amplify their emotional responses to unpleasant stimuli was related to psychological outcome after the sexual assault. The resilient individuals, that is, those who endured sexual assault without developing emotional symptoms, were able to enhance the activation of emotional brain circuitry in response to unpleasant stimuli more than either those with PTSD or healthy controls who had never experienced a serious sexual assault.
Corresponding author Dr. Antonia New explained the findings: "This raises the possibility that the ability to focus on negative emotions permits the engagement of cognitive strategies for extinguishing negative emotional responses, and that this ability might be related to resilience. This is important, since it has implications for how we might enhance resilience."
These findings suggest that exposure to extremely stressful situations may leave an "emotional scar" that may influence the capacity to be resilient to the impact of subsequent stressors, even when one does not develop PTSD. "These data seem to support an idea that has emerged from clinical descriptions of resilient people, i.e., that people who are resilient are able to be flexible in the way that they respond to changing emotional contexts. It would be helpful to know how we can enhance the flexible activation of these prefrontal cortex networks in people with compromised resilience," commented Dr. John Krystal, Editor of Biological Psychiatry.
Dr. New agrees, adding that "perhaps the enrichment of the broad capacity to tolerate negative emotional experiences might be helpful in promoting resilience. Further work needs to be done on whether the feature of this capacity that relates to resilience is about the ability to tolerate one's one responses, or whether it is the ability to respond distress in others."
Journal reference:
New et al. A Functional Magnetic Resonance Imaging Study of Deliberate Emotion Regulation in Resilience and Posttraumatic Stress Disorder. Biological Psychiatry, 2009; 66 (7): 656 DOI: 10.1016/j.biopsych.2009.05.020
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