The role of social and behavioral risk factors in explaining racial disparities in age-related cognitive impairment: a structured narrative review.

Alzheimer's disease (AD) is a growing public health concern with large disparities in incidence and prevalence between African Americans (AAs) and non-Hispanic whites (NHWs). The aim of this review was to examine the evidence of association between six modifiable risk factors (education, smoking, physical inactivity, obesity, social isolation, and psychosocial stress) and Alzheimer's disease risk in AAs and NHWs. We identified 3,437 studies; 45 met inclusion criteria and were included in this review. Of the examined risks, education provided the strongest evidence of association with cognitive outcomes in AAs and NHWs. This factor may operate directly on Alzheimer's disease risk through the neurocognitive benefits of cognitive stimulation or indirectly through social status.