Of all possible anti-aging remedies, none has been as intriguing to scientists as calorie restriction, the idea that dramatically reducing food intake can unlock an extended lifespan.
The method works in rodents, which live on average 30 to 40 percent longer when subjected to a calorie restriction diet. But there’s no good way to find out whether it would also make humans live longer, and the data from a pair of studies on primates have been inconclusive. Now a new study suggests rhesus monkeys really do live longer and healthier lives with calorie restriction, offering the best evidence yet that humans could benefit as well.
Calorie restriction doesn’t mean starvation. It means providing all the nutrients necessary for survival, just not a whole lot on top of that. Of course, such a severe diet doesn’t provide much margin for error before malnutrition becomes a serious risk, which is one reason researchers remain skeptical that it could ever work in humans. Throw in the basic fact that any study of human longevity would take several decades to complete — and there’s no ethical or practical way to keep people on a near-starvation diet for that long, especially with no guarantee of a health benefit — and calorie restriction in humans doesn’t seem very promising for now.
But two research teams, one at the University of Wisconsin-Madison and the other at the National Institute of Aging (NIA), have now provided more clarity on how such extreme diets affect rhesus monkeys, the closest relatives to humans ever tested.