Calorie Restriction and Aging

The first suggestion that the process of aging might not be inevitable—or at least that it could be slowed—emerged about 70 years ago. Scientists discovered that when animals are forced to live on 30% to 40% fewer calories than they would normally consume, something unusual happens: they become resistant to most age-related diseases—cancer, heart disease, diabetes, Alzheimer’s disease—and live 30% to 50% longer.

Scientists set out to understand what genes are turned on by calorie restriction because if they could figure that out, they might be able to develop medications that turn those genes on just like calorie restriction does (but without people having to drastically reduce food intake). Over the past 15 years, scientists at MIT and Harvard Medical School identified a family of genes called sirtuins that are responsible for the health benefits of calorie restriction. Then they developed compounds called sirtuin-activating compounds (STACs) that turn on the sirtuin genes. The first STAC is called resveratrol, which is found in red wine. Resveratrol can extend the life span of simple organism like yeast, fruit flies, worms, and fish. In late 2006, resveratrol was shown to extend the life span of mice fed a high-calorie, high-fat diet. Not only did it extend life span in all these animals, but the animals were protected against several diseases of aging and remained physically active and vital until very late in their extended lives.

It’s easy to see why this research is potentially relevant to humans. Like the mice in these studies, many of us are middle-aged mammals who eat a high-calorie, high-fat diet. While research results in mice do not always prove true in humans, they often do. Still, we are a long way from knowing whether human life span can be extended, and the added years made vital and active, by such knowledge of the biology of aging.

Reprinted from HealthBeat