25 Jan 2010
Life-long calorie restriction seems to lead to longer lives.
by Amy Barth
From the January-February special issue; published online January 25, 2010 Discovermagazine.com
To stave off aging, Americans spend billions of dollars every year on supplements, gyms, even therapists. But a report released in July suggests that the secret to a longer life may simply involve a new twist on an old adage: Watch what you eat.
A study of adult rhesus macaques showed that the monkeys were one-third as likely to die from age-related diseases if they consumed 30 percent fewer calories than they did in their regular diet. Previous, well-publicized research had shown that restricting calories can increase the life span of creatures ranging from fruit flies to dogs, for reasons still unclear. But the latest trial, led by geriatrics expert Richard Weindruch at the Wisconsin National Primate Research Center and published in Science, is the first to show that caloric restriction can improve survival in primates.
This kind of research takes enormous patience. Weindruch has spent 20 years studying his monkeys. In that time, the dieting ones have shown reductions in diabetes, cancer, cardiovascular disease, and even brain atrophy. They are also visibly fluffier and sturdier compared with their fully fed counterparts. “Slowing the aging process through calorie restriction spills over to primates and probably people,” Weindruch says.
Pharmaceutical companies are now seeking a drug that mimics the benefits of a restrictive diet without the sacrifice. In July an independent team reported in Nature that rapamycin, an immune-suppressing drug, increases longevity in elderly mice by up to 38 percent. At the Jackson Laboratory in Maine, gerontologist David Harrison and his team chose to test rapamycin, which is already approved for use in procedures such as kidney transplants, because previous research showed that the drug increases the life span of flies and may reduce cancer in mammals. “We’re not claiming to achieve immortality,” Harrison says, “but rapamycin is a step toward expanding healthy life span by about 10 years.”