ALZHEIMER'S DISEASE LESS PREVALENT AMONG CHEROKEE INDIANS.

Byline: Sue Goetinck Knight-Ridder Tribune News Wire

Cherokee Indians have genetic insurance against Alzheimer's disease, Dallas and Oklahoma researchers have reported.

In this month's issue of the Archives of Neurology, a team of scientists from the University of Texas Southwestern Medical Center at Dallas, the University of Oklahoma College of Medicine and other institutions described a study of 52 members of the Cherokee Nation from northeastern Oklahoma.

Twenty-six had Alzheimer's disease and 26 didn't. Using genealogical data from the Cherokee Nation Tribal Registration Department, the researchers discovered that as the proportion of Cherokee ancestry goes up, their risk for developing the brain disorder goes down.

For example, among people 65 or older who were at least half Cherokee, about 34 percent had Alzheimer's disease. In contrast, about 65 percent of people of the same age who were less than half Cherokee had the disease. The researchers also found that the protective effect of being Cherokee decreased with age.

The next step, said UT Southwestern's Roger Rosenberg, is to figure out which gene or genes are decreasing the incidence of Alzheimer's.

``If we could understand how ... (the gene) prevents it,'' he said, ``eventually it might lead to some treatment.''

The findings fit with what's known about the ancestry of American Indians, Dr. Rosenberg said. American Indians descended from Asian people, who have less Alzheimer's disease than Caucasians.