Alzheimer’s and Lifestyles : Social activity may be a factor, study in AMA Journal suggests
In Japan, Alzheimer’s disease is unusual. In the U.S. and other Western countries, it’s much more common. So what happens when a Japanese man grows up and grows old in America?
That’s the question a group of researchers at the National Institute of Aging began studying in 1965. Their conclusion, published last week in the Journal of the American Medical Assn. (JAMA), is that his chances of suffering the impairments of mind and memory associated with Alzheimer’s quickly come to resemble those of his American neighbors.
Too many hamburgers and not enough tofu? Other studies have implicated America’s high-fat diet for the higher rates of heart disease seen when Japanese immigrate to the United States. Now the JAMA study finds that the men who ate the largest amount of soy tofu had the most severe cases of Alzheimer’s. (Researchers believe that the plant estrogens in tofu block the body’s naturally occurring estrogens from protecting the brain.)
The JAMA study, which followed 3,734 men since 1965, implicates two less obvious causes. The first is particular to the Japanese men: Many of them, after immigrating to Hawaii, worked in agricultural fields where pesticides may have led to neurological impairment. The second cause, however, was what the JAMA editors called “the lifestyle alterations that result from such migrations.” While the editors did not describe these alterations, one of the study’s leading researchers, Dr. Lon White, suggested that the Japanese men may have been less socially stimulated in their new environment.
It’s a finding that should interest all Americans, for Alzheimer’s is currently the third-most expensive disease to treat in the United States (after heart disease and cancer).
The JAMA study adds to a growing body of evidence that the way we live our lives can affect the onset of the disease. Some studies already suggest that the solitary lifestyles common among elderly Americans can leave the brain unstimulated, thus leading to a smaller reserve of functioning brain cells.
The incidence of Alzheimer’s disease is expected to climb dramatically as the average age of the U.S. population rises. The fight against it, these studies suggest, should go on not only in the laboratory but throughout our society. There’s no reason why old age can’t be as social and healthfully stimulating as youth.
