Calories Versus Birthdays
Prior to the new findings, the only reliable way to prolong life in several mammal species has been a calorie-restricted diet, Conti says.
In 1935 scientists discovered that mice fed 40 percent fewer calories lived up to 50 percent longer than mice on full-calorie diets.
Such calorie-restricted diets not only increase life expectancy but also produce lower body temperatures.
Severe calorie-restriction can also delay the onset of age-related diseases, research has found.
But such diets are hardly practical, Conti says.
"Maybe there is a way that we can improve life span and health span without necessarily undergoing a strict diet," he said.
His study doesn't offer any immediate ways to extend the human life span, he adds, but the findings do provide a new model for understanding how aging works.
Clifford Saper, a Harvard Medical School neuroscientist, says the new study is the first to test the hypothesis that lowering body temperature prolongs life.
The finding yields some tantalizing prospects, he notes.
"The substantial increase of life span raises the question of whether mild hypothermia might be easier to tolerate than a lifetime of starvation as a way to increase longevity," he writes in any accompanying Science perspective.
Gene therapypossibly delivered by a virus to the same temperature-regulating area of the brain that was altered in the micemay be available in the future, Saper says.
In the meantime another recent mouse study published yesterday in the journal Nature suggests a more low-tech option currently available at the local liquor store.
Large daily doses of resveratrol, a substance found in red wine, appears to not only offset the ill effects of a high-calorie diet, but can significantly extend life span, the study suggests.
Free Email News Updates
Best Online Newsletter, 2006 Codie Awards
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
SOURCES AND RELATED WEB SITES