by GARY STIX
A skinny restricted-diet monkey is not expected to live longer than a portly companion
Aging researcher Thomas Kirkwood asked a roomful of scientists recently whether they thought that restricting calorie intake by 10 to 40 percent would extend lifespan, as it sometimes does in mice and roundworms. A majority of those present raised hands in assent. It has become a sort of conventional wisdom among scientists and the general public that calorie restriction extends lifespan. Even before hard scientific evidence was in, some people adopted the practice, foregoing rich desserts for the rest of their lives in the hope of arriving at a tenth or eleventh decade.
Kirkwood might get a very different response from the scientists he questioned if he asks the same question this afternoon or this evening. And it should be interesting to log onto the life-extension blogs and listservs in the wee hours.
A National Institute on Aging study published online today in Nature shows that more than 20 years of limiting calorie intake by 30 percent in a group of rhesus monkeys did not allow them to live longer than a control group of monkeys who were eating a normal, unrestricted diet. “I think the message is that a caloric restriction response, if it exists for monkeys and by implication humans, may occur only under the narrowest conditions,” says Steven N. Austad, a professor at University of Texas Health Science Center San Antonio, who wrote an accompanying commentary in Nature.
Scientific American for more