We’ve long known that African-Americans have a higher risk of Alzheimer’s disease than white Americans. But we’ve never had a clear explanation—until now. A study being presented this week at the Alzheimer’s Association International Conference in Boston says socioeconomic factors are to blame for that disparity.
The Alzheimer’s Association’s 2013 Alzheimer’s Disease Facts and Figures reports older African-Americans are twice as likely to suffer from aging-related dementia or Alzheimer’s as white counterparts. (Hispanics are 1.5 times as likely to have Alzheimer’s.)
The study at the University of California, San Francisco and the San Francisco Veterans Affairs Medical Center surveyed about 3,000 black and white elderly people over 12 years. Though the black participants seemed to show more of a propensity to develop dementia, the researchers found the difference was not statistically significant after adjusting for patients’ income levels.
High blood pressure and diabetes can increase one’s risk of developing Alzheimer’s disease later in life, according to the 2013 facts and figures report. These conditions are more prevalent in poorer communities.
Dr. Kristine Yaffe, who led the study, said in a statement that the findings suggest researchers should better control for socioeconomic factors in future studies about demographics of aging populations.
These findings come on the tail of other recent research showing no genetic differences explaining the disease’s racial disparity.
An estimated 5.2 million Americans have Alzheimer’s disease, the 2013 association report says. The condition is under-diagnosed, and the Alzheimer’s Association estimates about half of those 5.2 million people do not know they have the disease. This is particularly true in black and Hispanic communities, where missed and mis-diagnoses are common, according to the report.
The report estimates Massachusetts will have 140,000 residents living with Alzheimer’s by 2025.