Scientists are discovering that what you eat, how frequently, and how much may have an effect on quality and years of life. Of particular interest has been calorie restriction, a diet that is lower by a specific percent of calories than the normal diet but includes all needed nutrients.

Research in animals has shown calorie restriction of up to 40% fewer calories than normal to have an impressive effect on disease and markers of aging. It has been found to extend the life of protozoa (very small, one-celled organisms), yeast, fruit flies, mice, and rats, as well as other species.

Calorie restriction studies with humans and other primates (such as monkeys) are ongoing. Early findings of the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) study show that slightly overweight adults who cut their calorie consumption by 20 to 30% lowered their fasting insulin levels and core body temperature. Both of these changes correlate with increased longevity in animal models. Some studies in nonhuman primates have also shown that calorie restriction reduces the incidence of certain diseases such as cancer. However, not all the studies demonstrated this effect on longevity. For example, in some species of mice, calorie restriction even appears to shorten lifespan.

Scientists do not know if long-term calorie restriction is safe or practical for humans. While a calorie-restricted diet may never be widely adopted for people, studying calorie restriction offers new insights into the aging process and biological mechanisms that could influence healthy aging. This research may also provide clues about how to prevent or delay diseases that become more prevalent with age and inform the development of treatments for such diseases.

While research into calorie restriction and intermittent fasting continues, there is already plenty of research supporting the value of a healthy, balanced diet and physical activity to help delay or prevent age-related health problems.

Visit the National Institute on Aging website for new and updates on healthy aging research.

Next month: Have you read claims for “anti-aging” hormone therapies, such as human growth hormone and hormone replacement therapy? In the February 2011 Caring Right at Home, we will take a look at NIA research on these substances and their effects.

Right at Home is a national organization dedicated to improving the quality of life for those we serve. We fulfill that mission through a dedicated network of locally owned, franchised providers of in-home care and assistance services.