Exercise benefits the mind too

Exercise seems to slow the descent toward dementia as well.

Two sets of data from the Mayo Clinic Study of Aging suggest that exercise may positively influence how mild cognitive impairment (a precursor to dementia) and dementia develop.

In one group of patients with mild cognitive impairment, exercising seemed to protect against developing dementia. Data on a different group of healthy patients who exercised -- either lightly or vigorously -- showed they were less likely to be diagnosed with cognitive impairment.

"We would never say that these things totally prevent Alzheimer's, that they will cure you," said Coleman, a geriatrician. "But they're going to help your brain."

A smell test may detect Alzheimer's

In the future, a test of your sense of smell may help doctors predict your risk of developing Alzheimer's disease.

In two separate studies, scientists found that people who were unable to identify certain odors were more likely to experience cognitive impairment. The researchers believe that brain cells crucial to a person's sense of smell are killed in the early stages of dementia.

Researchers say this information could help doctors create a smell test to detect Alzheimer's earlier. Early detection means early intervention and treatment to slow the progression of the disease. Doctors today can only diagnose Alzheimer's disease once it has caused significant brain damage.

"In the face of the growing worldwide Alzheimer's disease epidemic, there is a pressing need for simple, less invasive diagnostic tests that will identify the risk of Alzheimer's much earlier in the disease process," Heather Snyder, director of medical and scientific operations for the Alzheimer's Association, said in a statement.