health & nutrition

Wednesday, July 13, 2005

why some people react severely to emotional stress

(HealthDay News) -- It may not be thick skin that protects you from emotional pain, but a thick brain.

Scientists have discovered that variations in the size of an area of the brain called the ventromedial prefrontal cortex may explain why some people recover from trauma better than others. Specifically, people with a thicker ventromedial prefrontal cortex (vmPFC) exhibited better ability to inhibit fear.

The research, which appears in this week's issue of the Proceedings of the National Academy of Sciences, may be an important clue in the age-old mystery of why some people react severely and continuously to emotional trauma while others don't.

There may be numerous clinical implications to the research, the study authors said.

"One would be the idea that perhaps people with a thinner cortex in this area might be at greater vulnerability for developing anxiety disorders, but that's still a speculation," said senior study author Dr. Scott Rauch, director of the Psychiatric Neuroscience Research Division at Massachusetts General Hospital, in Boston. "This could also be a potential predictor of responses to [certain types of] behavior therapy."

Some people associate certain cues with traumatic memories so that, when they are exposed to the cue, the memory comes flooding back. In other words, certain sounds or sights trigger a recall of the previous, traumatic experience. The most obvious example of this is post traumatic stress disorder (PTSD).

For most people, this sensitivity diminishes over time and the fearful response goes away, something called "extinction memory."

For others, however, the fear persists.

Earlier animal and other studies had indicated that the vmPFC, on the lower surface of the brain, might be involved in this process.

To see if individual differences in fear extinction correlated to vmPFC size, the study authors recruited 14 healthy volunteers. On the first day, each person was given photos to look at, and then an electric shock. Then they viewed the photos without the shock.

The next day, the volunteers looked at the same photos while researchers monitored changes in electrical activity in the skin -- an indication of anxiety level. The participants then underwent brain scans with structural magnetic resonance imaging.

Those who had smaller skin responses -- in other words, less anxiety -- also had a thicker vmPFC, the researchers said.

"This was the only region in the brain that showed the significant relationship to extinction memory," said study author Mohammed Milad, a research fellow in the department of psychiatry at Massachusetts General Hospital.

Although the finding is an important one, many questions remain, said Paul Sanberg, director of the University of South Florida Center for Aging and Brain Repair, in Tampa.

For instance, do some people just have a thicker vmPFC and, therefore, a better ability to recover from trauma, or is the ability to cope with stress acquired? Some studies have shown the brains of people and animals tend to get bigger in a mentally stimulating environment, Sanberg said.

It's also not clear what mechanisms are at work in that region of the brain, Sanberg said. "Is it more neurons or more glial cells, is it connections, or is it the neurochemistry?" he asked.

Rauch said, "The most obvious connection [of the research] would probably be to PTSD, but we believe it certainly has implications for panic disorder and potentially for other anxiety disorders such as phobias."

The research may have broader implications for treatment, he added. "All of those anxiety disorders are responsive to extinction-based behavior therapy," Rauch said.

Dr. Rodrigo Kuljis is a professor of neurology and psychiatry at the University of Miami School of Medicine. He said the new research "is interesting. It tends to support the feeling that certain aspects of memory are mediated by certain parts of the brain. It could be used eventually as a measure to determine if someone is more susceptible to certain conditions and also to predict treatment."

The real question, Kuljis said, is whether the new findings can be corroborated. "It's very sophisticated imaging but the bottom line is you are measuring something [the vmPFC] that is around a centimeter thick at best, probably thinner," he said. "The resolution of the instrument is marginal, but it's the best we have. The margin of error is enormous." --- (msn.com)

Exercise Can Stall Effects of Aging

(HealthDayNews) -- Many people think physical decline is an inevitable consequence of aging.

Think again, says the President's Council on Physical Fitness and Sports. While there are some factors beyond your control, much of the physical frailty often attributed to aging is the result of an inactive, sedentary lifestyle.

Exercise protects against heart disease and other chronic conditions such as adult-onset diabetes, arthritis, hypertension, certain cancers, osteoporosis and depression.

Research also shows physical activity eases tension and reduces stress. To put it simply, exercise is one of the best ways to stay young and healthy.

overweight women much fitter than male peers

(HealthDay News) -- Adding a new spin to the battle of the sexes, researchers say severely obese women outperform their male counterparts when it comes to both physical fitness and their ability to properly digest carbohydrates.

"Society is putting much more calories in food today than 50 years ago, and people are getting more and more overweight. But we found that the women were better able to handle the obesity than the men," said study co-author Dr. Emile F. L. Dubois, from the department of pulmonary diseases at the Hospital Reinier de Graaf Groep in Delft-Voorburg, The Netherlands.

The study found extremely obese women displaying better endurance and respiratory capacity during exercise than similarly heavy men.

The men also fared worse than women in terms of a condition called "carbohydrate intolerance." Unable to utilize carbs as the high-energy fuel source they are meant to be, people with this condition typically store unprocessed, excess carbohydrates as body fat.

Taken together, this lack of fitness and inability to handle carbs places severely obese men at a higher risk than equally sized women for developing "metabolic syndrome," a precursor to diabetes and heart disease, the researchers said.

The syndrome describes a range of health risk factors -- including high blood pressure, diabetes and obesity -- that contribute over time to the onset of serious disease.

Reporting in the July issue of Chest, Dubois and his colleagues focused on 56 severely obese Dutch patients -- 22 men and 34 women, all white. None was known to have a history of heart disease or diabetes.

With an average age of 42, all the patients were scheduled to undergo a form of bariatric surgery intended to help them lose weight by having their stomachs wrapped with a restraining band. The procedure, known as "gastric banding," is usually recommended for patients with a body mass index (BMI) of over 40.

Each patient took part in a weight-management program in preparation for surgery, involving access to a dietician as well as nutritional information, an exercise program, and -- in some cases -- medication.

Blood samples were taken, and all patients were assessed for evidence of carbohydrate intolerance and diabetes. Hormone levels and body fat composition were also calculated, and all the men and women completed a bicycle exercise test to observe respiratory health, muscle strength and fatigue.

According to the researchers, men generally failed to meet expectations on the cycle test while women exceeded the anticipated results.

The women demonstrated better lung capacity -- and significantly better endurance -- when exercising than the men, the study team found.

In addition, 59 percent of the men were found to be either carbohydrate-intolerant or diabetic, compared with just 35 percent of the women.

Dubois and his team concluded that gender plays a major role in how well obesity is tolerated.

"We were surprised by our findings," Dubois said. "We had the idea that severely obese men and women would both have muscle and endurance capacities above normal, because they're carrying a lot of weight around all day long. But this was only true among women. The men really under-performed."

Dubois suggested a range of potential explanations, including the possibility that women are naturally more efficient at energy storage due to the role they play as a food source for newborns. Another theory is that hormones produced by fat tissue -- including estrogen -- might partially explain gender differences. Men could be more negatively affected than women by the release of these hormones, Dubois speculated.

But the most promising explanation might be linked to the distribution of fat around the body. Men, he noted, tend to store it in the upper parts of their bodies and directly inside muscle tissue, whereas women store fat in the lower body area. This may lead to a relatively greater diminishment in lung capacity among men, because abdominal muscles are compressed under the weight of stored fat.

Dr. Ken Fujioka, an expert in nutrition and metabolism at the Scripps Clinic in San Diego, agreed that fat distribution may indeed account for the fitness gap.

"We've known for years that women tolerate obesity better than men, and our guess is that it's hormone-mediated," said Fujioka. "It's mainly because men store fat centrally around the organs and in the abdominal area, while women store it in their hips and thighs. And essentially when you increase the fat in the abdominal area, insulin levels have to rise, and you increase pressure on the abdominal cavity. So I'd have to say they're right. It'll be harder to intake oxygen and breathe."

Alice H. Lichtenstein, director of the Cardiovascular Nutrition Lab at the USDA Human Nutrition Research Center at Tufts University in Boston also agreed this line of reasoning might have merit.

"It's true that there is a difference between men and women in body fat distribution," she said. "And men tend to have more central obesity, so that could be the issue influencing what they've observed. But more research is needed. In the end, it's hard to say." --- msn.com

Group calls for health warnings on soft drinks

A U.S. consumer group on Wednesday called for cigarette-style warnings on soft drinks to alert consumers that too much of the sugary beverages can make people fat and cause other health problems.

People who overindulge in soft drinks are also more likely to develop diabetes and have decaying teeth, the Center for Science in the Public Interest (CSPI) said in a petition to the Food and Drug Administration.

The warnings are especially needed to counter the growing number of young people who drink soda, said the center.

"Soda pop used to be an occasional treat. Now it's an everyday beverage," CSPI executive director Michael Jacobson said, adding that it is all calories and no nutrients.

The latest government data from 2002 shows teenage boys drink an average of two 12-ounce cans of soda a day compared to about 1.33 cans for teenage girls, Jacobson said.

Food and beverage industry groups rejected the call for warnings, saying obesity has complex causes and packages already list calories and ingredients.

"Individuals, not the government, are in the best position to make the food and beverage choices that are right for them," said Susan Neeley, head of the American Beverage Association (ABA).

Others, including the industry-funded Center for Consumer Freedom, said regulating sodas would limit consumer choice.

Some firms have reintroduced smaller packages, but CSPI said cheap prices and multiple-serving bottles attract consumers.

Government warnings are needed to "push the public to a healthier diet as aggressively as the soft drink industry, the fast food industry and others push people in the other direction," Jacobson said.

Coca-Cola Co. and Cadbury Schweppes Plc did not return calls for comment. PepsiCo Inc. referred calls to the ABA. -- source ( reuters.com)

why vegan?

Vegan?? - A strict vegetarian; someone who eats no animal or dairy products at all.

Wondering what could be some of the reasons why people would want to give up their juicy steaks, tantalizingly sweet ice creams, sharp cheddar cheese and many other non-vegan treats? Some may say that meat eaters are helping to kill helpless animals who deserve the right to live free from the suffering that men impose upon them.

There are many animal rights groups, such as Action For Animals, PETA, and NARN, that proclaim that animals aren’t allowed to live out their natural life cycles in the name of economic gain. Lets look at it from a different prespective. The main advantage of living on a vegan diet is that one gets nutrients straight from the source. Instead of getting your nutrition from cows that get nutrition from grains and other plants, you take it directly from the ground and save your body the burden of having to digest animal flesh, which the body doesn’t easily assimilate.

The stark truth of the matter is that some of the meat that a non-vegetarian eats stays stuck in that person’s colon for many years, unless cleansing methods are used. The meat processing industry is notorious for administering heavy-duty antibiotics and hormones to ensure that their animals make it to the slaughterhouse is the least amount of time.

Even though the body employs the mucous system to protect the body from absorbing too much of the toxins the level of absorption of nutrients in the foods we are ingesting is reduced over a period of time. The toxins can wear down and disintegrate the linings of the colon leaving the toxins to run over into the system, making it necessary for the liver and other organs to cycle them.

A smart thing to do is to observe the dynamics at work in our universe by employing a vegan diet. On a spiritual level we know that animals are spiritual beings, but on a physical level not using animals for food would free up much farmland for growing food directly for humans. Now ranchers would have their lands to raise crops and the suffering of these animals would be ended. People would see that the effects of many chronic ills, that have been prevalent for such a long time now, would now be miraculously lessened or even cured in some cases.

The use of hormones and antibiotics, for ensuring that cattle get to the slaughterhouse as fast as possible, is staggering. These tactics don’t bode well for the health of people who ingest these ingredients, unsuspectingly into their bodies, while eating their meat.

Almost all refined and processed food causes the body to overwork itself in metabolizing it. The body wants a water-based diet, which it can metabolize easily, using the enzymes that are found in fresh fruits and vegetables, to digest them rapidly and reaping their nutritional content without damaging our cells.

Refined sugar and flour are two of the most menacing foodstuffs found in the processed foods on our grocery store shelves. It should be declared that foods that take inordinate amounts of energy from our body when we process them are in fact poisons, because they actually rob the body of nutrients.

There is no separation between mind, body, and environment. If we persecute animals and treat them as soulless beings it gives us the karma of treating ourselves as less then their equals, because we aren’t respecting their, and at the same time our own, spiritual nature. All creation is all one.

Being vegan is a big step in realizing our own true nature, in taking responsibility for healing the planet and ourselves. It is one way we learn that our actions do affect the environment, and that what we put into our bodies, as well as what we put out through our thoughts, actions, and words mightily affect the quality of our lives.

Awareness is the key. Knowing that our energy is the same as that of the animals. That all of the different dimensions of reality are connected and realizing that we have a leading role in preserving the connection of mind, body, and environment; as well as being stewards of this earth, is one of the main lessons that we as a species have to learn and master, before we will be able to move up the evolutionary ladder and live our lives in creative, compassionate play.
-------from a web source.