Fit Tip Move to protect your memory. Multiple studies show exercise decreases toxic tau proteins and increased blood flow to the brains of people who have a risk of dementia--better than any drug. "Exercisers have brains with more white matter, a kind of tissue that's thought to act like electrical wiring, keeping all the parts of the brain talking to each other," says Stephen Rao, a professor at the Schey Center for Cognitive Neuroimaging in Cleveland. "Right now, the best thing you can do to prevent Alzheimer's is to get on a treadmill or start why not get up and move?"