Beat Alzheimer's with exercise.

Charlotte Schubert

Exercise helps to flush a toxic molecule from the brain and causes a beneficial one to move in and protect nerve cells, research on mice shows. The discovery might help to explain why staying fit and keeping mentally active seem to fend off Alzheimer's disease in humans. "Our experiments support the idea that exercise is a good approach to all types of problems in the brain and that a sedentary lifestyle is a risk factor," says Ignacio Torres-Aleman, who led the study at the Cajal Institute in Madrid.Torres-Aleman and his colleagues were intrigued by previous studies showing that exercise slows mental decline in mice engineered to mimic Alzheimer's disease. They set out to discover the reason.They found that exercise doubled the levels of a protein that helps to flush molecules thought to underlie Alzheimer's disease out of the mice's brains and into their blood. The protein, called megalin, ejects a potentially destructive protein called amyloid-beta. In Alzheimer's patients, amyloid-beta accumulates in clumps throughout the brain.
Megalin also binds to a beneficial molecule in the blood, called insulin-like growth factor, and transports it to the brain. This growth factor is perhaps best known for bulking up muscles after exercise, but it also helps to keep nerve cells healthy.

Experiments support the idea that exercise is a good approach to all types of problems in the brain. Running could keep the brain as well as the body healthy.