| In a prospective study involving data collected from 23,943 subjects without pre-existing cancer and myocardial infarction/stroke at baseline, who were followed for an average of 11 years, during which time 1,101 deaths were documented (cancer deaths=513; cardiovascular deaths=264), baseline users of antioxidant vitamin supplements were found to have a significantly reduced risk of cancer mortality (HR=0.52) and all-cause mortality (HR=0.58). Interestingly, subjects who started taking vitamin supplements during the follow-up period had significantly increased risks of cancer mortality (HR=1.74) and all-cause mortality (HR=1.58), as compared to baseline non-users. The authors state that this finding, "may suggest a "sick-user effect," which researchers should be cautious of in future observational studies." They conclude, "Based on limited numbers of users and cases, this cohort study suggests that supplementation of antioxidant vitamins might possi bly reduce cancer and all-cause mortality." | Reference: | "Vitamin/mineral supplementation and cancer, cardiovascular, and all-cause mortality in a German prospective cohort (EPIC-Heidelberg)," Li K, Kaaks R, et al, Eur J Nutr, 2011 July 22; [Epub ahead of print]. (Address: Division of Cancer Epidemiology, German Cancer Research Centre, Heidelberg, Germany). | |