SOME JAPANESE-AMERICAN MEN SHOW HIGHER ALZHEIMER'S RATE.

Byline: Damaris Christensen Medical Tribune News Service

Unknown cultural or environmental factors may influence the development of Alzheimer's disease, according to a new study showing that elderly Japanese-American men had a higher rate of Alzheimer's disease than their counterparts living in Japan.

While Japanese people have lower overall rates of Alzheimer's disease than Americans, the new study of 3,734 Japanese-American men ages 71 to 93 who lived in Hawaii for all or most of their lives found that these men were about as likely as other American men to develop the degenerative brain disease that causes memory loss and confusion.

The study, published in last week's Journal of the American Medical Association, found that 5.4 percent of the men had Alzheimer's.

In addition, 4.2 percent of the men had another form of dementia, known as vascular dementia - a condition that stems from diseased blood vessels in the brain, the study showed. Unlike with Alzheimer's, this rate is similar to that in Japanese men. In the United States, however, rates of vascular dementia are lower, according to lead researcher Dr. Lon White, chief of the National Institute on Aging's Asia-Pacific office in Honolulu.

This seems to indicate that there is some cultural or environmental factor that influences the development of Alzheimer's, but not of vascular dementia, according to White.

``This important study is provocative and addresses one of the major questions of Alzheimer's research - the relation between genetic and nongenetic influences,'' said Zaven Khachaturian, director of the Alzheimer's Association's Ronald and Nancy Reagan Research Institute.

``Many of these late-onset diseases are not caused by a single factor,'' he said. ``We have a more complex notion of the disease, and this study points the way for new studies to take such environmental or cultural effects more seriously.

``Like lung cancer, it's not just the gene that causes the disease but something else that you do,'' he added.

Dr. Richard J. Havlik, of the National Institute on Aging in Bethesda, Md., which is funding the ongoing study, said that future research will attempt to identify factors in the Western lifestyle that might contribute to Alzheimer's.

Such factors may include higher consumption of meat and dairy products, occupational exposure to pesticides (since many of the men worked in pineapple and sugar cane farms in Hawaii) or stress associated with a lower socioeconomic status, he said.