Physical activity, not just exercise, may lower the risk of Alzheimer's, according to a new study published in the journal Neurology.

Researchers at the Memory and Aging Project at Rush University Medical Center in Chicago found that even tasks as simple as playing cards, cooking, gardening, and washing dishes can make a person less likely to suffer from dementia.

"The implication of this study is really astounding," lead author Dr. Aron Buchman said. "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," he said.

During the study, 71 of the 716 participants developed Alzheimer's. The bottom 10 percent of study participants with the least amount of physical activity were almost three times as likely to develop Alzheimer's.

The study is the latest evidence that physical activity, even at an older age, can help in delaying Alzheimer's.