Using an environmental justice framework to examine cumulative effects of particulate matter and access to antioxidant rich foods on blood pressure

Residents of predominantly African American and Latino communities and those with lower socioeconomic status are disproportionately exposed to environmental hazards. Air pollution exposure results in increased oxidative stress, linked to poor cardiovascular outcomes. Antioxidant supplements may play a modulating role on the acute effect of air pollutants. The majority of studies have been conducted with dietary supplements, rather than examining variations in total dietary intake. We used an environmental justice framework to assess the role of dietary antioxidants in modifying the adverse effects of exposure to PM2.5 on blood pressure (BP) and to consider implications for health inequities.

Methods We used data from the Healthy Environments Partnership (HEP), approved by the University of Michigan's Institutional Review Board. We use Generalized Estimating Equations (GEE) to test simultaneously for the effect of ambient exposure PM2.5 and dietary antioxidant intake. Models adjusted for demographics, medication use, and related health conditions.

Results Dietary antioxidant intake was negatively associated with systolic BP (beta=-1.6, p-value=0.02) and pulse pressure (beta=-0.7, p-value=0.08), after accounting for the effect of ambient exposure of PM2.5. We did not identify a significant modulating effect of dietary antioxidant on ambient exposure.

Conclusions Our findings are consistent with results reported elsewhere (Marchioli 2003, Jenkins et al. 2008), indicating that dietary antioxidants are associated with decreased blood pressure. These effects may help to mitigate negative effects of PM2.5 on cardiovascular health. Neighborhoods with excess exposure to PM2.5 and reduced access to antioxidant rich foods may be particularly vulnerable to the negative health effects of PM2.5.