Higher magnesium intake may reduce stroke risk

A new Swedish meta-analysis suggests that increased magnesium intake may lower the risk of ischemic stroke.

To assess the relationship between magnesium intake and stroke risk, seven epidemiological prospective studies – with 6,477 cases of stroke among the 241,378 participants – were employed in a meta-analysis (1). The analysis showed a modest but statistically significant association between increased magnesium intake and a reduced stroke risk: for each 100 mg increase in magnesium intake, the stroke risk was 8% lower. This association was found in ischaemic strokes, but not ‘haemorrhagic’ strokes.

The researchers commented that since the analyzed studies were epidemiological in nature, they could not show whether magnesium is truly preventative of ischaemic strokes. However, they speculated on a few mechanisms by which magnesium might protect against stroke, including the mineral’s ability to lower blood pressure, bring about favorable changes in blood sugar and blood fat levels, and reduce oxidation of blood fats.

The term ‘stroke’ describes the manifestation of death in part of the brain. It most commonly occurs as a result of the blocking off of one or more arteries – called ‘ischaemic’ stroke. More rarely, strokes can be caused by arteries bleeding into the brain – so-called ‘haemorrhagic’ strokes. Prospective studies of dietary magnesium intake in relation to stroke risk have yielded inconsistent results in the past.

1. Larsson S. C. et al. Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies. Am J Clin Nutr. Published online December 2011.