Nurses Health Study - Higher magnesium levels linked to lower risk of stroke

Nurses Health Study - August 2014.

Findings derived from the Nurses’ Health Study suggest a protective effect for magnesium against the risk of ischemic stroke in women. The study, described online on August 12, 2014 in the American Heart Association journal Stroke, included 459 Nurses’ Health Study participants who experienced an ischemic stroke prior to June 2006 and an equal number of control subjects matched for age, ethnicity and other factors.

Blood samples collected between 1989 and 1990 were analyzed for plasma magnesium. Subjects whose magnesium levels were among the lowest fifth of participants had a risk of stroke that was 34% higher than those whose levels were among the top fifth. Those whose levels were lower than 0.82 micromoles per liter had a 57% greater risk of total ischemic stroke, and a 66% higher risk of thrombotic stroke than women who had higher levels.

To authors Sally N. Akarolo-Anthony and her associates’ knowledge, the association between magnesium levels and ischemic stroke risk has been evaluated in another prospective study. They remark that although only 1% of the body’s magnesium exists in plasma, levels are strongly correlated with intracellular magnesium and could be a better indicator of the mineral’s status than dietary intake.

They note that risk factors for stroke, including diabetes and hypertension, have been associated with reduced magnesium levels, and that there is evidence that magnesium could help protect against blood clot formation.

“The results of this study suggest that low plasma magnesium may be associated with increased risk of ischemic stroke,” the authors conclude. “If confirmed, our findings may have significant public health impact because magnesium deficiency is potentially modifiable.”