Air pollution exposure and incidence of cardiometabolic diseases: Exploring the modifying role of dietary antioxidant intake in adults

While the antioxidative potential of certain vitamins and minerals in cardio-protection has garnered increasing interest, their ability to attenuate associations between air pollution exposure and cardiometabolic diseases (CMDs) remains unexplored. This study examined the associations of air pollution (particulate matter including ultrafine particles (UFP), and nitrogen oxides, including NO₂ and NO_x) and six dietary antioxidants with incident non-fatal CMDs in 30,519 EPIC-NL study participants. Data on CMD incidence (total cardiovascular disease (CVD), acute myocardial infarction (AMI), coronary heart disease (CHD) and heart failure (HF)) and Type 2 Diabetes Mellitus (T2DM) diagnoses were obtained from medical registries. Annual average ambient concentrations of air pollutants at the participants' baseline residential addresses were predicted using land use regression models. Dietary intake of antioxidants was assessed via a food frequency questionnaire. Multivariable Cox regression models were used to explore associations. Exposures to NO₂ and UFP were associated with elevated HF risk (Hazard Ratio (HR) (95 % CI): 1.24 (1.00, 1.54) and 1.69 (1.04, 2.76), respectively). Higher beta-carotene intake was associated with reduced risk of total CVD and CHD incidence (HR (95 % CI): 0.94 (0.89, 0.99) and 0.92 (0.84, 0.99), respectively), whereas, in general, antioxidant intake was positively associated with incident T2DM. Interaction analyses indicated some variability in CMD risk by antioxidant intake, but none of these interactions remained significant after correcting for multiple comparisons. These findings indicate that the associations of air pollution with incident CMD do not differ by dietary antioxidant intake.