Scientists have found that eating a lower calorie diet could increase the life spans of rhesus monkeys. Researchers are now studying if the same principle applies in humans.
A team of researchers from the University of Wisconsin-Madison have published the results of a 25-year study on the effect of calorie-restricted diets on the aging process of monkeys. Their findings show that eating a calorie-restricted diet showed a notable reduction in the occurrence of age related diseases in the monkeys. Moreover, eating fewer calories also increased the life spans of the monkeys. The team published the completed study in the online journal Nature Communications.
"We think our study is important because it means the biology we have seen in lower organisms is germane to primates," said UW-Madison professor of medicine Richard Weindruch. "We continue to believe that mechanisms that combat aging in caloric restriction will offer a lead into drugs or other treatments to slow the onset of disease and death." Weindruch is also one of the founders of the study.
On average, the lifespan of rhesus monkeys bred and raised in captivity is approximately 26 years. However, the researchers found that their special calorie-restricted diet could extend the lives of the monkeys by at least four years and the rhesus monkeys who took part in the study lived over 30 years.
"We study caloric restriction because it has such a robust effect on aging and the incidence and timing of age related disease," said UW-Madison assistant professor of geriatrics Rozalyn Anderson, a corresponding author of the study. "Already, people are studying drugs that affect the mechanisms that are active in caloric restriction. There is enormous private-sector interest in some of these drugs."
In comparison to their long lived brethren, the rhesus monkeys in the control group that did not have calorie restrictions were three times more likely to develop age-associated diseases. The scientists are now looking at the possible implications the findings have on prolonging the life spans of other primates as well as the possible effects on humans.
"We are not studying it so people can go out and do it, but to delve into the underlying causes of age-related disease susceptibility," said Anderson. "It's a research tool, not a lifestyle recommendation, but some people get caught up: 'What if I did caloric restriction?'"
The problem with testing the effects of a calorie-restricted diet on humans is that only a very small percentage of humans can actually tolerate the required 30 percent calorie reduction in their diets. However, there is growing interest in the development of drugs that can reproduce the same mechanisms seen in caloric restrictions.
"The basic biology of caloric restriction in rodents, worms, flies and yeast seems to carry over to primates, so we have a real opportunity to dissect that mechanism, look at how we can work with that basic biology, and benefit all those human primates who are so closely related to our rhesus monkeys," Weindruch added.
