Study Tracks Why Eating Less Extends Life

By REUTERS

ASHINGTON, Nov. 30 — Scientists say they have made progress in understanding why eating less leads to longer life.

Studies of yeast, rodents and other organisms found that drastically cutting calories extended life, and researchers are trying to find out how that happens. They hope to develop drugs to mimic the effect in humans.

In a report in the current issue of the journal Science, the researchers said studies of fruit flies showed that an enzyme called Rpd3 histone deacetylase is probably vital.

"If you decrease the level of enzyme without eating less, you still get life span extension," said Stewart Frankel, a scientist at Yale and the senior author of the study.

In the study, flies with genetic mutations that brought lower levels of the enzyme lived significantly longer than normal. With a low-calorie diet as well, they lived 41 percent longer.

Dr. Frankel cautioned that a drug to safely produce the effect in people may be years away.

One drug, phenylbutyrate, is thought to lower the Rpd3 enzyme, Dr. Frankel said. An earlier study showed that it extended the lives of fruit flies.

Blanka Rogina and Stephen Helfand of the University of Connecticut Health Center helped in the study.