Dietary anthocyanin intake and age-related decline in lung function: longitudinal findings from the VA Normative Aging Study

Background: It is unknown if habitual intake of dietary flavonoids, known for their antioxidative and anti-inflammatory properties, affects longitudinal change in lung function. Objective: We investigated if different flavonoid subclasses present in the habitual diet were associated with beneficial changes in lung function over time in the elderly. Design: This longitudinal analysis included 839 participants from the VA Normative Aging Study whose lung function (FEV1 and FVC) was measured at two and up to five visits between 1992 and 2008 (n = 2,623 measurements). Yearly average intake of major flavonoid subclasses (anthocyanins, flavanones, flavan-3-ols, flavonols, flavones, and polymers) was calculated from food-frequency questionnaires at each visit. We estimated adjusted differences in annual change in lung function associated with each flavonoid subclass, categorized into quartiles, in linear mixed-effect regression models after adjustment for lifestyle and dietary confounders. Results: Strong inverse associations were found between anthocyanin intake and age related decline in lung function. Independent of dietary and non-dietary risk factors, slower rates of FEV1 and FVC decline by 23.6 mL/y (95% confidence interval [CI]: 16.6,30.7) and 37.3 mL/y (95%CI: 27.8, 46.8), respectively, were observed in participants in the fourth quartile of intake compared with participants in the first quartile (Ptrend < 0.0001). The protective associations observed for anthocyanin intake were present in both current/former and never smokers. Compared with no or very low intake, intake of ≥ 2servings/week of anthocyanin-rich blueberries was associated with slower decline in FEV1 and FVC by 22.5 mL/y (95%CI: 10.8, 34.2) and 37.9 mL/y (95%CI: 22.1, 53.7),respectively. To a lesser extent, higher flavan-3-ol intake 92 was also associated with slowerlung function decline. Conclusion: Attenuation of age-related lung function decline was associated with higher dietary anthocyanin intake in this longitudinal sample of predominantly elderly men.Further prospective studies are needed to confirm these novel associations.