biomedicine: link between aging and eating found

Scientists have long known that calorie-restricted diets can extend the lives of creatures ranging from yeast to fruit flies to mice. (A few, very hungry people are trying to see if it works for humans, too.) But exactly why near-starvation diets make animals live longer remains unclear. Now MIT’s Leonard Guarente and colleagues offer a first step in explaining how two such different processes as eating and aging could be related in the June 2 online issue of Nature. In yeast, longevity is promoted by a gene called SIR2. The researchers studied the mouse version of this gene called Sirt1 and discovered that it is activated by scarcity of food. During times of hunger, Sirt1 turns off receptors that lay down fat deposits, preventing the body from storing fat and releasing it to be metabolized. So long life through dieting may involve the body’s fat-deposition machinery. “We’d like to think this applies to people as well as mice, but we don’t know for sure,” stated Guarente in a press release. “If we could make this happen in people, it wouldn’t just make them live longer; it might also help prevent diseases of aging, like cancer, diabetes and heart disease.”

This news brief appeared in the Discoveries column of the Boston Globe’s Health/Science section on 6/08/2004.