Intake of specific carotenoids and risk of lung cancer in 2 prospective US cohorts

Background: Carotenoids may reduce lung carcinogenesis because of their antioxidant properties; however, few studies have examined the relation between intakes of individual carotenoids and lung cancer risk. Objective: The aim of this study was to examine the relation between lung cancer risk and intakes of α-carotene, β-carotene, lutein, lycopene, and β-cryptoxanthin in 2 large cohorts. Design: During a 10-y follow-up period, 275 new cases of lung cancer were diagnosed in 46924 men; during a 12-y follow-up period, 519 new cases were diagnosed in 77283 women. Carotenoid intakes were derived from the reported consumption of fruit and vegetables on food-frequency questionnaires administered at baseline and during follow-up. The data were analyzed separately for each cohort and the results were pooled to compute overall relative risks (RRs). Results: In the pooled analyses, α-carotene and lycopene intakes were significantly associated with a lower risk of lung cancer; the association with β-carotene, lutein, and β-cryptoxanthin intakes were inverse but not significant. Lung cancer risk was significantly lower in subjects who consumed a diet high in a variety of carotenoids (RR: 0.68; 95% CI: 0.49, 0.94 for highest compared with lowest total carotenoid score category). Inverse associations were strongest after a 4-8-y lag between dietary assessment and date of diagnosis. In subjects who never smoked, a 63% lower incidence of lung cancer was observed for the top compared with the bottom quintile of α-carotene intake (RR: 0.37; 95% CI: 0.18, 0.77). Conclusion: Data from 2 cohort studies suggest that several carotenoids may reduce the risk of lung cancer.