Alzheimer's protein may fight infection

Beta amyloid destroys signals between nerves, causing people to lose their memory.

The protein has been thought of as a useless waste product, though scientists at Harvard Medical School say it may be a defense against invading bacteria and other microbes, The New York Times reported Friday.

In studies, beta amyloid killed eight out of 12 microbes killed by LL-37, a protein in the body's immune system believed to protect against brain infection and atherosclerotic plaques, arterial growths that impede blood flow, said Harvard researchers Rudolph Tanzi and Robert Moir.

The research could give scientists clues about how to eliminate beta amyloid from the brain.

"It means you don't want to hit (beta amyloid) with a sledgehammer," Tanzi said. "It says what we need is the equivalent of a statin for the brain so you can dial it down but not turn it off."

Copyright 2010 United Press International.