Alzheimer's prevention: Exercise tops the list

By Sheilah Downey

Every 70 seconds, someone will develop Alzheimer's disease, states the Alzheimer's Association website.

New numbers released Monday from the 2009 World Alzheimer's Report estimate that 35 million people worldwide are afflicted with the disease and the numbers are expected to reach an alarming 115.4 million by the year 2050.

With research into Alzheimer's raising hopes globally that a cure may one day be found, many health officials maintain that exercise is still the number one preventative measure.

"Regular physical exercise is probably the best means we have of preventing Alzheimer's disease today," said the Mayo Clinic's Dr. Ronald Petersen, in a 2008 interview. "Better than medications, better than intellectual activity, better than supplements and diet."

One reason exercise works, studies indicate, is that when the body exerts itself, the brain releases an enzyme that prevents build up of a plaque thought to lead to Alzheimer's disease.

Researchers at the University of Chicago studied mice to who were bred to develop the Alzheimers-induce brain plaque. For the study, some of the mice were allowed to exercise while others were not. Results indicated that the physically active mice had 50 to 80 percent less brain plaque than the sedentary mice.

A Columbia University study published in August found that diet along with exercise had a two-pronged effect.

Researchers followed a group of 1,880 New Yorkers, all in their 70s, and   assessed their diets and levels of physical activity for a five-year period. Participants were evaluated periodically for signs of Alzheimer's disease.

The people who ate the healthiest diets were 40 percent less likely to develop Alzheimer’s than those with the worst diets, researchers reported.

Those who exercised the most were 37 percent less likely to develop the disease than those who got none.

But the greatest benefits, said the study, were in those who ate healthy diets and remained active. Study participants who scored in the top third for both diet and exercise were 59 percent less likely to get Alzheimer’s disease than those in the lowest third.