Mice kept in a germ-free room with intensive nursing care at Harvard Medical School are hopefully the key to this side effect. A mouse gym holds a miniature exercise machine that tests the rodents’ ability to balance on a bar, while in a nearby water maze, mice must recall visual cues from their "training" to swim to safety on a hidden platform - thereby testing memory powers. (Don't worry: the that forget their lessons are rescued as they start to submerge.)

The new drugs being tested are called Sirtuin activators, and are based on a theory that most species have an ancient strategy for riding out famines: switch resources from reproduction to tissue maintenance. These activators appear to be triggered in mice when fed a healthy diet with 30 % fewer calories. The mice seem to live longer because they are somehow protected from the usual diseases that kill them.

Left to our own devices, many of us couldn't stick to a diet that requires a 30% cut in calories, so a drug that could initiate this "famine" reflex is what the study is working toward. Safety tests in people have just started, with no adverse effects so far.

The hope is that activating sirtuins in people would, like a calorically restricted diet in mice, avert degenerative diseases so often linked to aging - things like diabetes, heart disease, cancer and Alzheimer's. Because the FDA doesn't have a specific approval category for longevity drugs, if the drug resulting from this study is submitted for approval, it needs to be for a specific disease.

Read more at my Anti-Aging blog.