Abstract 851: Associations of dietary calcium and magnesium intakes with lung cancer risk among low-income Americans: Results from the Southern Community Cohort Study

Abstract

Abstract Background: Previous studies have suggested the potential roles of dietary intakes of calcium and magnesium in human cancer development, but little is known about their associations with lung cancer risk, especially among African Americans (AAs) and low-income populations. Objectives: We conducted a nested case-control study to investigate the associations of dietary calcium and magnesium intakes with lung cancer risk among a low-income population of AAs and European Americans (EAs) in the Southeastern United States. Methods: A total of 1,560 incident lung cancer cases who were diagnosed at least two years after enrollment and 5,926 matched controls from the Southern Community Cohort Study were included. Dietary calcium and magnesium intakes were assessed using a validated food frequency questionnaire at study enrollment. Multivariate logistic regression models were used to estimate odds ratios (ORs) and corresponding confidence intervals (95% CIs) for lung cancer risk associated with intakes of calcium and magnesium, and calcium/magnesium ratios after adjusting for enrollment age, education, smoking status, and pack-years, physical activity, alcohol drinking, household income, history of chronic obstructive pulmonary disease, body mass index, energy intake, and calcium or magnesium intake. Results: Calcium intake was significantly associated with an increased risk of lung cancer among AAs but not among EAs; ORs (95% CI) for the highest compared with lowest quartiles were 1.56 (1.03-2.36) and 1.14 (0.68-1.92) for AAs and EAs, respectively (p for interaction: 0.03). Meanwhile, magnesium intake was significantly associated with a reduced risk of lung cancer risk among AAs but not among EAs; ORs (95% CI) for the highest compared with lowest quartiles were 0.55 (0.35-0.89) and 0.68 (0.39-1.18), respectively (p for interaction: 0.68). ORs (95% CI) for the highest compared with the lowest quartiles for calcium/magnesium ratios were 1.21 (0.96-1.53) for AAs and 1.17 (0.85-1.61) for EAs. These associations were more evident among men and never-smokers. Conclusion: Our results suggest that higher dietary calcium and lower dietary magnesium intakes are associated with an increased risk of lung cancer, especially among AAs, raising the possibility that dietary factors may contribute to a higher risk of lung cancer among AA than EA men. Citation Format: Hyung-Suk Yoon, Xiao Ou Shu, Hui Cai, Wei Zheng, William J. Blot, Qiuyin Cai. Associations of dietary calcium and magnesium intakes with lung cancer risk among low-income Americans: Results from the Southern Community Cohort Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 851.