Magnesium intake and colorectal tumor risk: a case-control study and meta-analysis

Am J Clin Nutr. 2012 Sep;96(3):622-31. doi: 10.3945/ajcn.111.030924. Epub 2012 Aug 1.


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/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).

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.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / complications
  • Adenoma / etiology
  • Adenoma / pathology
  • Adenoma / prevention & control
  • Age Factors
  • Body Mass Index
  • Carcinoma / complications
  • Carcinoma / etiology
  • Carcinoma / pathology
  • Carcinoma / prevention & control
  • Case-Control Studies
  • Colorectal Neoplasms / complications
  • Colorectal Neoplasms / etiology
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / prevention & control*
  • Diet* / adverse effects
  • Female
  • Humans
  • Magnesium / administration & dosage*
  • Magnesium / therapeutic use
  • Male
  • Neoplasm Staging
  • Overweight / complications
  • Risk


  • Magnesium