U.S.-African Study Suggests Lifestyle Factor in Alzheimer's

Environmental factors such as lifestyle and diet may play a role in the development of Alzheimer's disease, according to a new study by the Indiana University School of Medicine in partnership with the University of Ibadan in Nigeria, West Africa.

The study -- involving 2,147 Indianapolis residents and 2,459 Nigerians -- found that the Yoruba residents of Ibadan were much less likely to develop Alzheimer's disease than the African Americans.

The two groups are not genetically identical, but most African Americans have their ancestry in West Africa. The findings thus would seem to suggest that factors other than genetics may determine whether people develop the disease.

The next challenge, according to Dr. Hugh C. Hendrie, a psychiatry professor at Indiana University School of Medicine and lead author of the study, is to understand why the African Americans are so much more likely to get Alzheimer's disease.

One possibility, according to Hendrie, is vascular disease, as the Nigerians in the study had lower blood pressures and cholesterol levels that were as much as 60 points below the American study group.

Diet also would appear to be a possibility, the researchers said. The Ibadan group in the study were poor, traders at small markets, and their diet consisted of yams, cassava, palm oil and sometimes fish. The study group in Indianapolis ate a typical American diet.

Bill Thies, a vice president of the Alzheimer's Association, said the findings strongly suggest that lifestyle and environment play a role in causing Alzheimer's disease. "It's not only where you live but how you live that may increase your likelihood of developing Alzheimer's disease," Thies said.

Other sources: N.Y. Times, Reuters, AP, USA Today