Alzheimer's Study Offers New Prevention Clues

I N D I A N N A P O L I S, Feb. 14, 2001 -- A study has found that black Americans aretwice as likely to develop Alzheimer's disease as black Nigerians,suggesting that environment and lifestyle play a role in theneurological disorder.

The 10-year study, which was conducted in Indianapolis andIbadan, Nigeria, also concluded that American blacks are morelikely to develop high blood pressure, diabetes and other illnessesthan blacks in Nigeria.

Hugh Hendrie, a professor of psychiatry at Indiana UniversitySchool of Medicine, is the principal author of the study, whichappears in today's issue of the Journal of the American MedicalAssociation.

He said his IU team and their counterparts at the University ofIbadan now hope to determine why the Americans developedAlzheimer's and other forms of dementia more frequently than theirAfrican counterparts.

Link to Lifestyle?

Bill Thies, a vice president of the Chicago-based Alzheimer'sAssociation, said the findings strongly suggest that lifestyle andenvironment play a role in causing the mind-robbing disease.

"It's not only where you live but how you live that mayincrease your likelihood of developing Alzheimer's disease," hesaid.

More than 4 million Americans, most of them elderly, suffer fromAlzheimer's, which causes gradual memory loss, disorientation andpersonality changes.

The Indianapolis-Nigeria study enlisted 2,147 Indianapolisresidents and 2,459 Nigerians. About two-thirds of both groups werewomen.

Although the two groups were not a perfect match, it is believedthat many African-Americans descended from people brought from WestAfrica to the United States as slaves. Nigeria is in West Africa.

The Ibadan residents in the study are unable to afford much morethan vegetables to eat, Hendrie said, with a diet including yams,cassava and palm oil with an occasional sprinkling of fish.

The study participants in Indianapolis ate the typical Americandiet.

Moving Toward Prevention

All participants were 65 or older and were determined to have nosigns of dementia or Alzheimer's at the beginning of the study.

At the end of the study, 2.52 percent of the Americans haddeveloped Alzheimer's, and a total of 3.24 percent showed signs ofdementia. By contrast, 1.15 percent of the Nigerians had developedAlzheimer's, and 1.35 percent had dementia.

For the study's second phase, an additional 2,000 Indianapolisresidents age 70 or older will be recruited, said Hendrie, who isalso a researcher at the Center for Aging at the RegenstriefInstitute.

No volunteers will be accepted for the five-year study. Instead,participants will be sought out to ensure a representative sample.

The results of the initial part of the study are significant,Hendrie said, because it marks the first time that the same groupof scientists has investigated and compared the rate of an illnessin a developing and a non-developing country.

Often, researchers study different groups at different timesusing a variety of criteria, making analysis difficult. With thisstudy, researchers hope to move Alzheimer's research further towardprevention.

Hendrie said that the second part of the study will likely showthat Alzheimer's is rooted in a combination of genetic andenvironmental causes.