Fruit, vegetable, and fish consumption and heart rate variability: the VA Normative Aging Study

Authors: PARK, SUNG KYUN - UNIV OF MICHIGAN; O'NEILL, MARIE - UNIV OF MICHIGAN; HU, HOWARD - UNIV OF MICHIGAN; VOKONAS, PANTEL - VA BOS HEALTHCARE SYS.; SPARROW, DAVID - VA BOS HEALTHCARE SYS.; Tucker, Katherine; SCHWARTZ, JOEL - HARVARD SCH PUB HEALTH

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2008
Publication Date: 3/1/2009
Citation: Park, S., O'Neill, M.S., Hu, H., Vokonas, P.S., Sparrow, D., Tucker, K., Schwartz, J. 2009. Fruit, vegetable, and fish consumption and heart rate variability: the VA Normative Aging Study. American Journal of Clinical Nutrition. 89:778-786.

Interpretive Summary: A large body of epidemiologic literature has shown an association between fine particulate air pollution and cardiovascular mortality and morbidity. Recent air pollution epidemiologic studies have examined associations of fine particles with changes in sub-clinical biomarkers, such as heart rate variability (HRV). Reduced HRV, an indicator of cardiac autonomic dysfunction, has been linked with cardiac events and arrhythmia. Exposure to fine particles may adversely affect cardiac autonomic function, in part, through elevated oxidative stress. Increased intake of fruit and vegetables may provide defense against oxidative stress. An overwhelming body of evidence has demonstrated that higher intake of fruit and vegetables is associated with lower rates of all-cause, cancer, and cardiovascular disease (CVD) mortality. We examined whether higher intake of antioxidants (vitamin C, vitamin E, carotenoids, and cruciferous vegetables) and omega-3 fatty acids reduced particle associations with HRV in a community-based older population of 505 older men participating in the Normative Aging Study (NAS). To evaluate dose-dependent effects of dietary antioxidants and omega-3 PUFA, we used a self-administered semi-quantitative food frequency questionnaire (FFQ). Our results showed significant associations of HRV with vitamin C, carotenoids, cruciferous vegetables and omega-3 fatty acids. These results suggest that consumption of fruit, vegetables, and fish may modify the cardiovascular response to particle exposure by helping to prevent CVD directly, as well as reducing the risk of CVD associated with sources of oxidative stress, such as particulate air pollution. In addition, this study provides further evidence that oxidative stress is an important mechanism in cardiac particle toxicity.

Technical Abstract: Higher intakes of antioxidants (vitamins C and E, carotenoids) found in fruit and vegetables, and omega-3 fatty acids from fish, may prevent cardiovascular disease. We examined whether higher intake of such antioxidants and omega-3 fatty acids reduced effects of particles less than 2.5 µm in aerodynamic diameter (PM2.5) on heart rate variability in a community-based older population. Standard deviation of normal-to-normal intervals (SDNN), high frequency (HF) and low frequency (LF) powers were measured among 505 older men with 645 total observations from November 2000 to June 2005. Dietary intake was evaluated with a self-administered semiquantitative food frequency questionnaire. After controlling for potential confounders, associations of 48-hour average PM2.5 with SDNN, HF and LF were significantly attenuated across tertiles of vitamin C (all P-trends<0.05). The associations of SDNN and LF with PM2.5 were also reduced across tertiles of carotenoids (all P-trends<0.1). Furthermore, we found effect modification by cruciferous vegetables (P-interaction=0.03) and omega-3 fatty acids (Pinteraction= 0.08) on SDNN, comparing subjects in the bottom two tertiles with those in the top tertile. Effect modification by vitamin E was not statistically significant. Higher intakes of fruit, vegetables, and fish may reduce the cardiac autonomic nervous system impacts of particle exposures.