Racial discrimination, racial/ethnic segregation, and health behaviors in the CARDIA study

Objective Racial discrimination has been associated with unhealthy behaviors, but the mechanisms responsible for these associations are not understood and may be related to residential racial segregation. We investigated associations between self-reported racial discrimination and health behaviors before and after controlling for individual- and neighborhood-level characteristics; and potential effect modification of these associations by segregation. Design We used data from the longitudinal Coronary Artery Risk Development in Young Adults (CARDIA) study for 1169 African-Americans and 1322 whites. To assess racial discrimination, we used a four category variable to capture the extent and persistence of self-reported discrimination between examination at years 7 (1992-1993) and 15 (2000-2001). We assessed smoking status, alcohol consumption, and physical activity at year 20 (2005-2006). Segregation was examined as the racial/ethnic composition at the Census tract level. Results Discrimination was more common in African-Americans (89.1%) than in whites (40.0%). Living in areas with high percentage of blacks was associated with less reports of discrimination in African-Americans but more reports in whites. After adjustment for selected characteristics including individual- and neighborhood-level socioeconomic conditions and segregation, we found significant positive associations of discrimination with smoking and alcohol consumption in African-Americans and with smoking in whites. African-Americans experiencing moderate or high discrimination were more physically active than those reporting no discrimination. Whites reporting some discrimination were also more physically active than those reporting no discrimination. We observed no interactions between discrimination and segregation measures in African-Americans or whites for any of the three health behaviors. Conclusions Racial discrimination may impact individuals' adoption of healthy and unhealthy behaviors independent of racial/ethnic segregation. These behaviors may help individuals buffer or reduce the stress of discrimination.