Carotenoid intake and esophageal cancer risk: a meta-analysis

This meta-analysis was conducted to evaluate the association between intake of carotenoids and risk of esophageal cancer. A systematic search using PubMed, Cochrane Library, Web of Science, Scopus, CNKI, and CBM (updated to 6 May 2012) identified ten articles meeting the inclusion criteria with 1,958 cases of esophageal cancer and 4,529 controls. Higher intake of beta-carotene, alpha-carotene, lycopene, beta-cryptoxanthin, lutein, and zeaxanthin reduced esophageal cancer risk with pooled ORs of 0.58 (95% CI 0.44, 0.77), 0.81 (95% CI 0.70, 0.94), 0.75 (95% CI 0.64, 0.86), 0.80 (95% CI 0.66, 0.97), and 0.71 (95% CI 0.59, 0.87), respectively. In subgroup analyses, beta-carotene showed protective effects against esophageal adenocarcinoma in studies located in Europe and North America. Alpha-carotene, lycopene, and beta-cryptoxanthin showed protection against esophageal squamous cell cancer. This meta-analysis suggested that higher intake of carotenoids (beta-carotene, alpha- carotene, lycopene, beta-cryptoxanthin, lutein, and zeaxanthin) is associated with lower risk of esophageal cancer. Further research with large-sample studies need to be conducted to better clarify the potentially protective mechanisms of carotenoid associations risk of different types of esophageal cancer.