Is a low-calorie diet the secret to longevity?

Does the diet work?
Many studies done on laboratory animals document that daily, extreme calorie restriction is associated with increases in longevity of up to 50 percent. Moreover, the aging process appears to “slow down” and restricted-calorie animals look and act much younger than their control partners of similar ages. Some biological markers, including cholesterol, blood pressure, and blood glucose, have also been found to be much lower in the restricted-calorie group. The lower weight that results from a restricted-calorie diet has a positive effect on the body’s joints and certainly the liver and pancreas have an easier time maintaining body function. (Both organs work overtime when you’re heavier.)

There is no evidence in humans that the length of a healthy life is increased by a restricted-calorie diet. However, many followers of the plan report improved health and a sense of well being with such restricted eating. It is difficult, though, to separate the effects of weight loss from those of eating fewer calories on our bodies. Also there is some evidence that dropping to an “underweight” category, which many restricted-calorie participants fall into, can put people at greater risk of illness. So, the final word is not yet in on restricted-calorie diets and human longevity.

How does it work?
Studies of the anti-aging effects of this diet are still in its infancy, and many of the reasons for why the restricted-calorie diet works are based on theories rather than on scientific fact. New medical findings are only made after years of scientific study. Many followers of the restricted-calorie diet are presently in controlled laboratory studies to look at the effects of this plan on their overall health.

While there have been numerous biological theories, based on the most recent laboratory studies, it seems that the restricted-calorie diet affects the most basic level of cell function. It somehow blocks the enzymes that enhance cell death during metabolic stress, resulting in a more vital, healthier animal. In fact, an antioxidant found in red wine, resveratrol, appears to provide the same biological function in preventing cell death. Further research should shed more information on the possible mechanisms behind the low-calorie diet’s effects.

Can this diet damage your health?
You should always check with your doctor before undertaking any change in your regular diet. With such a reduction in daily calories, there can be a risk of deficiencies when on the restricted-calorie diet, including protein malnutrition as well as low vitamin and mineral levels. It’s important to point out, though, that healthy followers of the restricted-calorie plan pay extreme attention to meeting their daily nutritional needs, which is a must to avoid health problems. Also, protein needs must be met to promote muscle repair and rebuilding, particularly since moderate exercise is an important part of any healthy lifestyle plan.

Dr. Fernstrom’s Bottom Line: For those who follow a restricted-calorie diet, they attribute it to improving their sense of well being. While we have ample evidence of this phenomenon in laboratory animals, the several thousand followers of this plan in the U.S. are an experiment in progress. For most people, a more modest reduction in their daily calories and weight may also provide a healthy outcome and improve longevity.

Eating Well with Madelyn Fernstrom The skinny on fat substitutes Eat healthy on a budget Bone up on calcium’s other benefits How safe is food irradiation? What’s your cholesterol IQ?

Madelyn Fernstrom, Ph.D., CNS, is the founder and director of the University of Pittsburgh Medical Center’s Weight Management Center. An associate professor of psychiatry, epidemiology, and surgery at the University of Pittsburgh School of Medicine, Fernstrom is also a board-certified nutrition specialist from the American College of Nutrition.

PLEASE NOTE: The information in this column should not be construed as providing specific medical advice, but rather to offer readers information to better understand their lives and health. It is not intended to provide an alternative to professional treatment or to replace the services of a physician.

MORE FROM HEALTH

Health Section Front

Three siblings get gift of hearing on same day Red wine or white? Which makes teeth a fright? Go nuts, pucker up: 16 easy ways to be healthier 239 lbs. lighter, he’s ‘Biggest Loser’ of all time And ‘The Biggest Loser’ is ... Your body's big enemy?  You’re sitting on it   Be careful of mail-order edible gifts Decking the halls? Watch out for danger Zhu Zhu Pets safe, safety regulators say 5 restaurant menu swaps for easy weight loss Health Section Front   Add Health headlines to your news reader: