Effects of particulate matter and antioxidant dietary intake on blood pressure.

OBJECTIVES: We assessed 2 pathways through which dietary antioxidants may counter adverse effects of exposure to particulate matter less than 2.5 micrometers in diameter (PM2.5) on blood pressure (BP): main (compensatory) and modifying (protective) models. METHODS: We used 2002 to 2003 data from the Detroit Healthy Environments Partnership community survey conducted with a multiethnic sample of adults (n = 347) in low- to moderate-income, predominantly Hispanic and non-Hispanic Black neighborhoods in Detroit, Michigan. We used generalized estimating equations to test the effects of ambient exposure to PM2.5 and dietary antioxidant intake on BP, with adjustment for multiple confounders. RESULTS: Dietary antioxidant intake was inversely associated with systolic BP (b = -0.5; P < .05) and pulse pressure (b = -0.6; P < .05) in neighborhoods closest to major sources of air pollutants. Adverse effects of PM2.5 remained significant after accounting for antioxidant intakes. Exploratory analyses suggested potential modifying effects of antioxidant intake on associations between ambient PM2.5 exposure and BP. CONCLUSIONS: Interventions to improve access to antioxidant-rich foods in polluted urban areas may be protective of cardiovascular health. However, efforts to reduce PM2.5 exposure remain critical for cardiovascular health promotion.