Magnesium intake reduces colorectal tumor risk - GreenMedInfo Summary
Magnesium intake and colorectal tumor risk: a case-control study and meta-analysis.
Am J Clin Nutr. 2012 Sep ;96(3):622-31. Epub 2012 Aug 1. PMID: 22854408
Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom, and the Division of Human Nutrition, Wageningen University, Wageningen, Netherlands.
BACKGROUND: Dietary magnesium might be related to colorectal tumor risk through the pivotal roles of magnesium in cellular metabolism, insulin resistance, and systemic inflammation.
OBJECTIVE: We evaluated the hypothesis of whether higher dietary magnesium intake is associated with reduced colorectal tumor risk.
DESIGN: A case-control study on colorectal adenomas (768 cases; 709 polyp-free control subjects) and a meta-analysis of colorectal adenomas (3 case-control studies) and carcinomas (6 prospective cohort studies) were conducted. Dietary magnesium was estimated from food-frequency questionnaires in the case-control study and most studies in the meta-analyses. Data analysis comprised multiple logistic regression analysis (case-control study) and fixed- and random-effects meta-analyses.
RESULTS: The case-control study showed a nonsignificant inverse association between dietary magnesium intake and risk of colorectal adenomas (OR for every 100-mg/d increase: 0.81; 95% CI: 0.62, 1.06). However, inverse associations were observed only in subjects with BMI (in kg/m(2))≥25, in subjects aged ≥55 y, and for advanced adenomas. Associations did not vary by the calcium-to-magnesium intake ratio. In the meta-analysis, every 100-mg/d increase in magnesium intake was associated with 13% lower risk of colorectal adenomas (OR: 0.87; 95% CI: 0.75, 1.00) and 12% lower risk of colorectal cancer (RR: 0.88; 95% CI: 0.81, 0.97).
CONCLUSIONS: Our findings support the hypothesis that higher intakes of dietary magnesium are associated with lower risk of colorectal tumors. The consumption of magnesium-rich foods may be a new avenue to explore further in the search for cancer-prevention strategies.