Cleaning house and doing yardwork are taking on new importance. A higher level of physical activity — not just exercising — is linked to a reduced risk of developing Alzheimer's disease even in people over 80, suggests research published Wednesday in the journal Neurology.

Protective activities include washing dishes, cooking, cleaning, gardening — even playing cards. People who scored in the bottom 10% of physical activity were more than twice as likely to develop Alzheimer's. Study participants did not have dementia at the start of the four-year study, which is part of the ongoing Memory and Aging Project at Rush University Medical Center in Chicago.

"The implication of this study is really astounding," says physician Aron Buchman, the lead author. "Exercise is good, without a doubt, but this study is about more than exercise. Older people who might not be able to exercise can tailor activities that are right for them."