Effect of dietary magnesium supplementation in the prevention of coronary heart disease and sudden cardiac death.

Magnesium may be important in the pathogenesis of coronary heart disease and sudden death. To study the role of magnesium, 400 high risk individuals were asked to volunteer either for a magnesium-rich diet (group A, 206) or for our usual diet (group B, 194) for 10 years in a randomized fashion. The age groups were between 25 and 63 years and the majority (374) of them were males. At entry to the study, age, sex, incidence of hypertension, diabetes, hypercholesterolemia, smoking, coronary disease and diuretic therapy were comparable. Dietary magnesium intake in group A (1,142 +/- 233 mg/day) was higher than in group B (418 +/- 105 mg/day). Total complications in group A (59; 28.6%) were significantly (p less than 0.001) less compared to group B (117; 60.3%). Sudden deaths were one and a half times more common in group B than in group A. Total mortality in group A (22; 10.7%) was significantly (p less than 0.01) less than in group B (34; 18.0%). A greater number of complications and increased mortality in group B subjects was consistent with a higher incidence of hypokalemia, hypomagnesemia and coronary risk factors in group B patients. Mean serum magnesium levels in group B participants were significantly (p less than 0.01) lowered compared to the mean magnesium level in group A participants who were administered the magnesium-rich diet. It is possible that increased intake of dietary magnesium in association with the general effects of a nutritious diet can offer protection against cardiovascular deaths among high-risk individuals predisposed to coronary heart disease.