Eat less, extend life
According to the results of a study published in the current issue of Science in this Reuters story in the New York Times (registration required):
"If you decrease the level of [the Rpd3 histone deacetylase] 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.
However, a drug that could stimulate this effect is years away. Rats!