Triggering a side effect -- longer life

The theory has become familiar: most species respond to famine by switching their energies away from reproduction and toward maintaining their bodies on less food. Mice fed a restricted diet live longer and seem to avoid disease, lab experiments have shown.

A story in today's New York Times highlights efforts by Boston scientists to set that famine reflex into motion in people -- without the deprivation a 30-percent calorie cut would mean. David Sinclair, a scientist at Harvard Medical School and co-founder of a company pursuing drugs based on the idea, is studying two ways to activate the enzyme sirtuin, which triggers the famine response. (His company, called Sirtris, was recently acquired by GlaxoSmithKline. Sinclair is a former student of MIT biologist Leonard Guarente, who founded the field of sirtuin biology.)

One sirtuin activator is the well-known compound resveratol, found in red wine but not in the amounts thought to make a difference in health. Another synthetic version is more powerful. Two Sirtris drugs are in clinical trials, the story says, one of them for treating type 2 diabetes.

Why diabetes? Drugs are approved by the Food and Drug Administration for treating diseases, not extending lifespan, the Times story explains. So Sirtris is searching for drugs to treat disease of aging, such as type 2 diabetes, heart disease, Alzheimer's, or cancer. The drugs, if successful, might bring along longevity in what Sirtris CEO Dr. Christoph Westphal calls "almost a side effect."

Sinclair has become more cautious, the story says.

“There’s a much greater chance of a drug that can treat disease than of extending life span,” Sinclair told the Times.

“I’m becoming more boring in my old age,” he added apologetically.