Alzheimer’s is the most common cause of dementia and it affects about one-third of adults age 85 and older in the U.S., but some populations are disproportionally impacted. For instance, African Americans are about twice as likely as whites to have Alzheimer’s or other dementias.

Though the causes are not fully understood, many factors likely contribute to the risk of Alzheimer’s and to the disparity in risk. Variations in health, lifestyle and socioeconomic risk factors across racial groups likely account for most of the differences in risk of Alzheimer’s and other dementias by race, according to the Alzheimer’s Association. Many risk factors for Alzheimer’s are more common among African Americans than non-Hispanic whites.

Health conditions such as cardiovascular disease, stroke, high cholesterol, high blood pressure, overweight/obesity and diabetes, which are associated with an increased risk for Alzheimer’s and other dementias, are more prevalent in African-Americans than whites. These are modifiable risk factors—conditions that can be treated.

Socioeconomic and environmental factors, such as lower education and income and greater experience of discrimination and early life adversity, may also increase African-American’s risk for Alzheimer’s. A new study funded by National Institute on Aging identified differences in some biological markers underlying Alzheimer’s disease in African Americans and non-Hispanic whites.

Having a family member with Alzheimer’s increases a person’s risk of having it. While researchers have not found a specific gene that directly causes Alzheimer’s, they have identified one that is associated with a higher risk risk. Having one form of the apolipoprotein E gene (APOE ε4) increases a person's risk of Alzheimer’s. APOE ε4 is also associated with an earlier onset of the disease. However, genetic factors do not appear to account for differences in the rate of Alzheimer’s among racial groups. (1)

Some of the risk and protective factors for cognitive decline are similar in African Americans and non-Hispanic whites. For example, the link between having greater depressive symptoms and a faster rate of cognitive decline does not differ by race. Also, cognitive activity, staying mentally active, and having a supportive social network are associated with slower cognitive decline in whites and African Americans.

There is also evidence that there are differences between African Americans and whites in access to care. African Americans are more likely to delay seeking help for Alzheimer’s and other dementias and less likely to receive Alzheimer’s treatment. While no treatments are available to slow or stop the progress of the disease, several medications are available to temporarily improve Alzheimer’s symptoms. Other therapies, such as computerized memory training, and exercise can help improve cognitive function and overall quality of life.

One of the challenges in understanding the racial differences in Alzheimer’s is that African Americans have been underrepresented in most of the research on Alzheimer’s. Past studies of Alzheimer’s disease diagnosis, treatment, management strategies and prevention have focused primarily on non-Hispanic white populations. This underrepresentation in research makes it more difficult to learn about how African Americans will respond to medications and other treatments and contributes to ongoing health disparities.

Early identification and treatment are important to help maintain quality of life and to help family members prepare and cope. If you are concerned about yourself or a loved one, talk with your doctor.