Fruit and vegetable consumption and risk of COPD: a prospective cohort study of men

Background Antioxidants present in fruits and vegetables may protect the lung from oxidative damage and prevent COPD. Aims To determine the association between fruit and vegetable consumption and risk of COPD by smoking status in men. Methods The population-based prospective Cohort of Swedish Men included 44 335 men, aged 45-79 years, with no history of COPD at baseline. Fruit and vegetable consumption was assessed with a self-administered questionnaire. Results During a mean follow-up of 13.2 years, 1918 incident cases of COPD were ascertained. A strong inverse association between total fruit and vegetable consumption and COPD was observed in smokers but not in never-smokers (p-interaction=0.02). The age-standardised incidence rate per 100 000 person-years in the lowest quintile (<2 servings/day) of total fruit and vegetable consumption was 1166 in current smokers and 506 in ex-smokers; among those in the highest quintile (>= 5.3 servings/day), 546 and 255 per 100 000 person-years, respectively. The multivariable HR of COPD comparing extreme quintiles of total fruit and vegetable consumption was 0.60 (95% CI 0.47 to 0.76, p-trend <0.0001) in current smokers and 0.66 (95% CI 0.51 to 0.85, p-trend=0.001) in ex-smokers. Each one serving per day increment in total fruit and vegetable consumption decreased risk of COPD significantly by 8% (95% CI 4% to 11%) in current smokers and by 4% (95% CI 0% to 7%) in ex-smokers. Conclusions These results indicate that high consumption of fruits and vegetables is associated with reduced COPD incidence in both current and ex-smokers but not in never-smokers.