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.
- COPD epidemiology
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Contributors JK had full access to all data in the study and takes responsibility for the integrity of the data analysis. JK, SCL, AL and AW contributed with study concept and design. JK and NO performed the statistical analysis. All authors helped to write the manuscript and performed critical revision of the manuscript for important intellectual content.
Funding This study was supported by a research grant from the Swedish Research Council/Infrastructure (AW), the Karolinska Institutet's Distinguished Professor Award (AW) and the Swedish Heart-Lung Foundation (AL) and from King Gustav V's and Queen Victoria's Freemason Research Foundation (AL). Federal funding was obtained in accordance with the ALF and LUA agreement, from Stockholm County Council (AL) and the Västra Götaland Region (AL).
Competing interests None declared.
Ethics approval The study was approved by the Regional Ethical Review Board at Karolinska Institutet (Stockholm, Sweden).
Provenance and peer review Not commissioned; externally peer reviewed.