Magnesium intake and colorectal tumor risk: a case-control study and meta-analysis
American Journal of Clinical Nutrition, 08/10/2012
Wark PA et al. – The 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.Methods
- 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.
- 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/m2) ≥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).