A trip to the gym alters DNA >for Science/DNA buffs

A bout of exercise sees methyl groups removed from metabolic genes.  Ruth Williams  06 March 2012  It is not just pounds you stand to lose when you hit the gym — your DNA also loses chemical modifications in the form of methyl groups, according to a paper published online today in Cell Metabolism1. Moreover, a similar effect is seen in cells given a high dose of caffeine, hinting at a possible trigger for the process.  The presence (or absence) of methyl groups at certain positions on DNA can affect gene expression. Juleen Zierath of the Karolinska Institute in Stockholm and her team looked at the methylation status of genes in small biopsies taken from the thigh muscles of healthy young adults before and after a stint on an exercise bike. They found that, for some genes involved in energy metabolism — such as PGC-1α, PPAR-δ and PDK4 — the workout demethylated the promoter regions, stretches of DNA that facilitate the transcription of particular genes. Genes unrelated to metabolism remained methylated.  The amount of demethylation at PGC-1α, PPAR-δ and PDK4 depended on the intensity of the exercise, with muscle biopsies from individuals who had cycled the hardest showing the greatest gene demethylation.  The findings will come as a surprise to many researchers in the field. “Once a cell becomes an [adult] cell type, let's say a muscle cell or a fat cell, it is generally thought that DNA methylation is stable,” says Ronald Evans, a molecular biologist at the Salk Institute for Biological Studies in La Jolla, California. “What Juleen is showing is that acute exercise changes the methylation status of the genome in actual muscle cells.”  Dynamic demethylation  Methylated DNA is generally associated with genes for which expression has been switched off. “When a promoter is heavily methylated,” Zierath explains, “that may somehow make it less accessible to transcription factors” — proteins that control the expression of one or more genes. In this way, Zierath says, methylation can “modulate or slow down the expression of genes”. Indeed, expression of PGC-1α, PPAR-δ and PDK4 was increased after exercise. However, whether demethylation was required for these genes’ activation is not clear.  Another detail that is unclear is how the methyl groups were removed from the DNA. There are few reports of rapid demethylation in mammalian cells, and enzymes that can demethylate DNA have only been identified in the past year or so2.There is, says Evans, “a rapid evolution in our understanding of the demethylation process. It is going to be different in six months if not three.” So this paper, he says, “is right in the middle of a very exciting area”.  Although the mechanism is unknown, Zierath’s study “re-enforces the notion that DNA methylation is more dynamic than previously appreciated”, says Helen Blau, a cell biologist at Stanford University in California. “It provides another paradigm to study promoter demethylation,” she says.  The researchers did manage to elucidate one part of the mechanism — they report that the demethylation was driven by muscle contraction itself rather than by any extrinsic exercise-induced signals. They saw the same gene demethylation in isolated cultured rodent muscle induced to contract.  Exercise or espresso?  Furthermore, similar demethylation could be seen when cultured muscle cells were given a massive dose of caffeine. “Caffeine releases calcium from the sarcoplasmic reticulum,” an organelle found in muscles, “and it sort of mimics a contracting muscle”, explains Zierath. Calcium might, therefore, be the cellular trigger that activates the demethylation pathway, she says.  Zierath cautions that this result does not imply that drinking coffee could be a replacement for exercise. Caffeine acts mainly through the central nervous system, and to see direct effects on muscle such as those in the rodent-cell experiments, “one would need to consume a caffeine equivalent of about 50 cups per day, almost close to a lethal dose”, she says. “Exercising is far easier if you ask me.”

A trip to the gym alters DNA | WorldHealth.net Anti-Aging Forum

Train Your Brain to Focus - Paul Hammerness, MD, and Margaret Moore - Harvard Business Review

Train Your Brain to Focus - Paul Hammerness, MD, and Margaret Moore - Harvard Business Review

Ode to Chocolate as a Health Food!

(Reuters) - Eating chocolate is not only a treat for the tongue -- it may also have some tangible benefits for heart health, such as lowering blood pressure slightly, according to a study involving more than a thousand people.

The study, which combined the results of 42 smaller studies and was published in the American Journal of Clinical Nutrition, also found that participants had small improvements in blood vessel function and a dip in their insulin levels.

A number of past studies have found that chocolate lovers seem to have lower rates of certain heart risks, such as high blood pressure.

"My take-away message would be that if people like dark chocolate, then eating a little in place of other 'treat' foods is fine, and may be beneficial," said study leader Lee Hooper, at Norwich Medical School in the UK.

"However, the evidence is not yet good enough to suggest that we should all be doing this."

She cautioned that the studies involved were neither large enough nor long enough to show whether eating chocolate has any effect on a person's risk of having a heart attack or stroke.

In contrast to past studies, which were largely observational and couldn't prove cause-and-effect -- that chocolate itself caused the changes -- the current study focused on clinical trials, where researchers assigned people to eat chocolate or not and then watched for changes in blood pressure, cholesterol and other heart risk factors.

Hooper and her team pooled data from 42 small clinical trials involving about 1,300 people and found that chocolate eaters had a few points knocked off their blood pressure readings, along with lower insulin levels and other benefits.

Though it's not clear why chocolate has this affect, it's believed to be due to compounds known as flavonoids, which are also present in foods such as nuts, soy, tea and wine.

But researchers acknowledged shortcomings in their study, including differences in the people involved in the trials -- some healthy, some with chronic health problems -- and different ways of testing chocolate's effects.

Some studies used cocoa drinks, some solid chocolate and some cocoa supplements. They also varied in how long people were "treated," though most trials lasted less than six weeks.

The biggest question may be whether any benefits would be worth the downside of chocolate. Based on the studies they used, Hooper's team writes, it could take several hundred calories' worth of chocolate to see effects on insulin and blood vessel function -- and that could mean trouble for your waistline.

"From a practical perspective it is premature to advise individuals to consume chocolate or cocoa to decrease their risk of cardiovascular disease," said Alice Lichtenstein, director of the cardiovascular nutrition lab at Tufts University in Boston, who was not part of the study.

For now, she added, if you enjoy a little chocolate in your life, you can probably keep doing so. Just don't add it in the hopes of helping your heart.

(Reporting from New York by Amy Norton at Reuters Health; editing by Elaine Lies)

Succeed: How We Can Reach Our Goals

Succeed: How We Can Reach Our Goals

The Mayo Clinic reviews OTC Weight Loss Products

This is an excellent list and evaluation of the effectiveness of currently used weight loss products, purchased at pharmacies, drug stores, nutrition stores.


By Mayo Clinic staff
The appeal of losing weight quickly is hard to resist. But do weight-loss pills and products lighten anything but your wallet? And are they a safe option for weight loss? Here's a look at some over-the-counter weight-loss pills and what they will and won't do for you.

Over-the-counter doesn't mean risk-free

A number of weight-loss pills are available at your local drugstore, supermarket or health food store. Even more options are available online. Most haven't been proved effective, and some may be downright dangerous.

Dietary supplements and weight-loss aids aren't subject to the same rigorous standards as are prescription drugs. Thus, they can be sold with limited proof of effectiveness or safety. Once a product is on the market, however, the Food and Drug Administration (FDA) monitors its safety and can take action to ban or recall dangerous products. Indeed, the FDA has banned the sale of supplements containing ephedra and other ephedrine-like ingredients.

Check the facts before you buy

It's important to do your homework if you're thinking about trying over-the-counter weight-loss pills. Read labels and talk with your doctor or pharmacist. Also be sure to check the FDA website for alerts about safety concerns and product recalls.

The table shows common weight-loss pills and what the research shows about their effectiveness and safety.

Product Claim Effectiveness Side effects
Alli — OTC version of prescription drug orlistat (Xenical) Decreases absorption of dietary fat Effective; but weight loss is even more modest than that with Xenical Loose stools, oily spotting, frequent or hard-to-control bowel movements; reports of rare, but serious liver injury
Bitter orange Increases calories burned Probably ineffective Similar to ephedra: raised blood pressure and heart rate
Chitosan Blocks absorption of dietary fat Probably ineffective Uncommon: upset stomach, nausea, gas, increased stool bulk, constipation
Chromium Decreases appetite and increases calories burned Probably ineffective Uncommon: headache, insomnia, irritability, mood changes, cognitive dysfunction
Conjugated linoleic acid Reduces body fat Possibly effective Upset stomach, nausea, loose stools
Green tea extract Decreases appetite, and increases calorie and fat metabolism Insufficient evidence to evaluate Dizziness, insomnia, agitation, nausea, vomiting, bloating, gas, diarrhea
Guar gum Blocks absorption of dietary fat and increases feeling of fullness Possibly ineffective Abdominal pain, gas, diarrhea
Hoodia Decreases appetite Insufficient evidence to evaluate Insufficient information available Sources: U.S. Food and Drug Administration, 2011; Natural Medicines Comprehensive Database, 2011
Include your doctor in your weight-loss plans

If you're considering trying weight-loss pills, be sure to talk with your doctor, especially if you have health problems or take prescription drugs. Your doctor can provide support and advice on losing weight and can monitor your progress. Just as important, your doctor can talk with you about possible side effects and what to watch out for.

In addition, your doctor can help determine if weight-loss pills are likely to interact with any prescription drugs you take. Many weight-loss pills contain multiple ingredients, such as herbs, botanicals, vitamins, minerals, and even caffeine or laxatives. If you take prescription drugs — or herbal or dietary supplements — adding weight-loss pills to the mix can be tricky.

Despite the hype, no quick fixes

The makers of weight-loss pills would like you to believe that their products will miraculously solve your weight problems. But keep in mind that even if you take a weight-loss pill, you still have to eat fewer calories than your body uses in order to lose weight. And even if these products help you lose weight initially, you will probably have to keep taking them to keep the weight off, which may not be practical or safe.

The reality is that there's no magic bullet for losing weight. The most effective way to lose weight and keep it off is through lifestyle changes: Eat healthy, low-calorie foods, watch portion sizes and be physically active. It's not magic, but it works.

References

Be the Best You Can Be in 2012

The new year is a great time to make positive changes in your life. 


Staying fit, or improving your present fitness level, is one of the most important resolutions you can make. 


The benefits of exercise for your health and well-being are many, and vitally important. Simply put, exercise helps you feel better, look great, and live a longer, healthier life.

Laughing is Fun and Important!

How Humor Makes You Friendlier, Sexier
Seeing the bright side of life may strengthen the psyche, ease pain and tighten social bonds
By Steve Ayan  | Wednesday, March 25, 2009 | 26

Norman Cousins, the storied journalist, author and editor, found no pain reliever better than clips of the Marx Brothers. For years, Cousins suffered from inflammatory arthritis, and he swore that 10 minutes of uproarious laughing at the hilarious team bought him two hours of pain-free sleep.

In his book Anatomy of an Illness as Perceived by the Patient (W. W. Norton, 1979), Cousins described his self-prescribed laughing cure, which seemed to ameliorate his inflammation as well as his pain.

He eventually was able to return to work, landing a job as an adjunct professor at the School of Medicine at the University of California, Los Angeles, where he investigated the effects of emotions on biological states and health.

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