Magnesium and sudden cardiac death in women

More evidence for the importance of magnesium in cardiovascular disease in general and sudden cardiac death in particular is offered in a paper recently published in The American Journal of Clinical Nutrition. The authors state:

"Magnesium has antiarrhythmic properties in cellular and experimental models; however, its relation to sudden cardiac death (SCD) risk is unclear...We prospectively examined the association between magnesium, as measured in diet and plasma, and risk of SCD."

They examined magnesium intake for 88,375 women participating in the Nurses' Health Study along with other nutrients and lifestyle factors for 26 years. During this time 505 cases of sudden or arrhythmic death were documented. Within this group they correlated plasma magnesium for 99 SCD cases and 291 controls who were matched for relevant variables such as age, smoking, and other elements of cardiovascular disease. What did their data show?

"After multivariable adjustment for confounders and potential intermediaries, the relative risk of SCD was significantly lower in women in the highest quartile compared with those in the lowest quartile of dietary and plasma magnesium. The linear inverse relation with SCD was strongest for plasma magnesium, in which each 0.25-mg/dL increment in plasma magnesium was associated with a 41% lower risk of SCD."

In other words, the women with the highest levels of plasma and dietary magnesium had a significantly lower risk for sudden cardiac death. The association was particularly strong for plasma magnesium (our functional reference range for plasma magnesium is 2.0-2.5 mg/dL). The authors conclude:

"In this prospective cohort of women, higher plasma concentrations and dietary magnesium intakes were associated with lower risks of SCD. If the observed association is causal, interventions directed at increasing dietary or plasma magnesium might lower the risk of SCD."

This data was generated within the Nurses' Health Study, but there is no reason to assume that the practical implications don't apply to men. You can easily see earlier reports on magnesium and cardiovascular disease by typing 'magnesium' in the search box. Clinicians and interested laypersons will further appreciate a forthcoming post on the association of intracellular magnesium and glutathione recycling, a critical process in the regulation of inflammation and nitric oxide production.