Why blacks have a higher risk.

• Position: Cognitive Impairment

Social and economic disadvantages play a significant role in why blacks face a much higher risk than whites of developing cognitive impairment later in life, indicates a study led by Zhenmei Zhang, associate professor of sociology at Michigan State University, East Lansing.

The odds that blacks will develop cognitive impairment--including dementia in later life--were 2.52 times greater than the odds for whites. Much of that racial disparity is explained by childhood disadvantages, such as growing up poor and in the segregated South, and lower socioeconomic status in adulthood, particularly educational attainment.

Surprisingly, racial differences in health problems, such as heart disease and diabetes, and health behaviors, such as smoking and drinking, did not explain much of the racial gap in cognitive impairment, maintains Zhang. While the findings do not fully account for blacks' higher risk of cognitive impairment, they point to a strong need for policymakers to focus more on reducing racial gaps in socioeconomic resources over the life span.

"Social policies, such as increasing educational resources in...