Magnesium intake and incidence of stroke: Meta-analysis of cohort studies

Abstract

Background and aimsProspective cohort studies are inconsistent regarding the association between magnesium intake and the risk of stroke. The objective was to perform a meta-analysis to summarise the relationship between magnesium intake and risk of stroke in observational studies. Methods and resultsWe searched the PubMed and EMBASE databases for studies conducted from 1966 through August 2011. Prospective studies that provided relative risk (RR) estimates with 95% confidence intervals (CIs) for the association between magnesium intake and the risk of total stroke incidence or mortality were included. Data were independently abstracted by two investigators using a standardised protocol. Study-specific risk estimates were combined by using a random effects model.A total of eight studies, with 8367 stroke cases among 304,551 participants, were included in the meta-analysis. The summary RR indicated a significant association between the highest magnesium intake and reduced risk of total stroke (summary RR: 0.89; 95% CI: 0.82, 0.97); our dose–response analysis showed a borderline inverse association between magnesium intake and total stroke risk (an increment of 100 mg day−1; summary RR: 0.98; 95% CI: 0.95, 1.00). Subgroup analyses suggested a significant inverse association between highest magnesium intake and the risk of ischaemic stroke (summary RR: 0.88; 95% CI: 0.80, 0.98). ConclusionThe present meta-analysis of prospective cohorts suggests that higher magnesium intake is associated with reduced risk of total and ischaemic stroke. However, well-designed randomised controlled trials are needed to draw a definitive conclusion.