Background: Several modifiable risk behaviors (smoking, heavy alcohol use, inadequate physical activity, poor diet) and associated outcomes (overweight/obesity) have been causally linked to cancer incidence and related mortality. Research indicates that African Americans suffer disproportionately from the adverse consequences of these risk factors relative to other ethnic groups, even after accounting for differences in risk behavior prevalence. In addition, some studies suggest that African Americans may be more likely than other ethnic groups to engage in multiple risk behaviors.
Purpose: A better understanding of factors associated with cancer risk behaviors/outcomes is needed to inform interventions to reduce cancer risk among African Americans. Discrimination has been linked to risk behaviors in the literature, but the mechanisms underlying these associations are not well understood. Because perceived discrimination has been associated with elevated stress and depression, and because stress and depression have been implicated in cancer risk behavior engagement, these psychosocial factors may help to explain relations between discrimination and cancer risk behaviors/outcomes. The current study examined the mediating role of stress and depression in the association between perceived discrimination and smoking status, alcohol use, physical activity, fruit and vegetable consumption, and body mass index, as well as the total number of behavioral risk factors among 1363 African American adults (age=45+13, 75% female).
Methods: A nonparametric bootstrapping procedure was used to assess whether stress and/or depression mediated relations of discrimination and behavioral risk factors in single mediator models. All analyses controlled for age, sex, marital status, income, education, and employment status. Analyses involving body mass index were additionally adjusted for physical activity and fruit and vegetable consumption.
Results: Associations between discrimination and cancer risk factors were non-significant; however, there were several significant indirect effects. Specifically, discrimination had an indirect effect on smoking (CIs.95= .0012, .0109; .0003, .0096), physical activity (CIs.95= .0007, .0073; .0003, .0065), and number of risk factors (CIs.95= .0008, .0029; .0005, .0024) through stress and depressive symptoms. Greater discrimination was associated with greater stress and depression, which were each associated with a higher likelihood of current smoking, higher odds of low physical activity, and a greater number of behavioral risk factors. Additionally, discrimination had an indirect effect on body mass index (CIs.95= .0015, .0115) through depressive symptoms. Greater discrimination was associated with greater depressive symptoms, which were associated with higher odds of overweight/obesity. No indirect effects emerged for at-risk drinking or fruit and vegetable consumption.
Conclusions: Results suggest that perceived discrimination may influence certain behavioral risk factors for cancer through heightened levels of stress and depression. Interventions to reduce cancer risk among African Americans may need to address experiences of discrimination, as well as the stress and depression that these may engender.
Citation Format: Adolfo G. Cuevas, Lorraine R. Reitzel, Adams CE Claire, Yumei Cao, Nga NT Nguyen, David W. Wetter, Kellie L. Watkins, Seann D. Regan. The mediating role of perceived stress and depression in relations between perceived discrimination and cancer risk behaviors and outcomes among African American adults. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr B40.