A cohort study of dietary carotenoids and lung cancer risk in women (Canada)

Objective: To investigate the association between dietary carotenoid intake and lung cancer risk in women. Methods: A case-cohort study was undertaken in the Canadian National Breast Screening Study dietary cohort, which consists of 56,837 women who completed a self-administered dietary questionnaire. The cohort was recruited between 1980 and 1985, and during follow-up to the end of 1993 a total of 196 cohort members were diagnosed with incident lung cancer. For analysis, a subcohort consisting of a random sample of 5681 women was selected from the full dietary cohort. After exclusions for various reasons, the analyses were based on 155 cases and 5361 non-cases. Results: When compared to those in the lowest quartile level of intake, the adjusted incidence rate ratios (95% confidence intervals) for those in the highest quartile levels of alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein intake were 0.90 (0.51-1.58), 1.40 (0.76-2.59), 0.66 (0.33-1.32), 1.04 (0.61-1.76), and 1.26 (0.70-2.24), respectively; none of the associated tests for trend was statistically significant. Conclusion: These results suggest that there is no association between dietary carotenoid intake and lung cancer risk, at least for the range of intakes observed here.