Although it may seem paradoxical, scientists have known since the 1930s that animals on calorie-restricted (CR) diets often live up to 50% longer than normal. As you’ll see on Frontiers, several studies confirm that diets low in calories and high in nutrients extend the life span – and bring about a number of health benefits. The work of the scientists seen in this episode suggests that overeating may accelerate aging. Physician and longevity researcher Roy Walford has followed a calorie-restricted but nutrient rich diet for many years. Geriatric investigator Richard Weindruch is studying effects of CR in rhesus monkeys and rodents. The research animals receive essential nutrients, but their calories are limited.
The working hypothesis is that caloric restriction puts animals on a pathway favoring survival over growth and reproduction, says Ingram. “If you think about any organism’s use of energy, it’s got to evolve a mechanism for the most efficient use.”
When sufficient energy is not available, he adds, the organism "begins to divert energy away from this growth-reproduction strategy.
There are many potentially harmful or toxic chemicals present in the food we eat, whether occurring naturally, as contaminants, or as deliberate additives. But these chemicals are not necessarily harmful in small amounts; the effects they have depend upon the amounts that we consume.