Magnesium intake and risk of type 2 diabetes: meta-analysis of prospective cohort studies.

OBJECTIVE

Emerging epidemiological evidence suggests that higher magnesium intake may reduce diabetes incidence. We aimed to examine the association between magnesium intake and risk of type 2 diabetes by conducting a meta-analysis of prospective cohort studies.

RESEARCH DESIGN AND METHODS

We conducted a PubMed database search through January 2011 to identify prospective cohort studies of magnesium intake and risk of type 2 diabetes. Reference lists of retrieved articles were also reviewed. A random-effects model was used to compute the summary risk estimates.

RESULTS

Meta-analysis of 13 prospective cohort studies involving 536,318 participants and 24,516 cases detected a significant inverse association between magnesium intake and risk of type 2 diabetes (relative risk [RR] 0.78 [95% CI 0.73-0.84]). This association was not substantially modified by geographic region, follow-up length, sex, or family history of type 2 diabetes. A significant inverse association was observed in overweight (BMI ≥25 kg/m(2)) but not in normal-weight individuals (BMI <25 kg/m(2)), although test for interaction was not statistically significant (P(interaction) = 0.13). In the dose-response analysis, the summary RR of type 2 diabetes for every 100 mg/day increment in magnesium intake was 0.86 (95% CI 0.82-0.89). Sensitivity analyses restricted to studies with adjustment for cereal fiber intake yielded similar results. Little evidence of publication bias was observed.

CONCLUSIONS

This meta-analysis provides further evidence supporting that magnesium intake is significantly inversely associated with risk of type 2 diabetes in a dose-response manner.