Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies.

BACKGROUND: Prospective studies of dietary magnesium intake in relation to risk of stroke have yielded inconsistent results.

OBJECTIVE: We conducted a dose-response meta-analysis to summarize the evidence regarding the association between magnesium intake and stroke risk.

DESIGN: Relevant studies were identified by searching PubMed and EMBASE from January 1966 through September 2011 and reviewing reference lists of retrieved articles. We included prospective studies that reported RRs with 95% CIs of stroke for ≥3 categories of magnesium intake. Results from individual studies were combined by using a random-effects model.

RESULTS: Seven prospective studies, with 6477 cases of stroke and 241,378 participants, were eligible for inclusion in the meta-analysis. We observed a modest but statistically significant inverse association between magnesium intake and risk of stroke. An intake increment of 100 mg Mg/d was associated with an 8% reduction in risk of total stroke (combined RR: 0.92; 95% CI: 0.88, 0.97), without heterogeneity among studies (P = 0.66, I(2) = 0%). Magnesium intake was inversely associated with risk of ischemic stroke (RR: 0.91; 95% CI: 0.87, 0.96) but not intracerebral hemorrhage (RR: 0.96; 95% CI: 0.84, 1.10) or subarachnoid hemorrhage (RR: 1.01; 95% CI: 0.90, 1.14).

CONCLUSION: Dietary magnesium intake is inversely associated with risk of stroke, specifically ischemic stroke.