By Hans R. Larsen MSc ChE
GOTHENBURG, SWEDEN. Previous studies have shown that there is a significant correlation between mortality from cardiovascular disease and drinking water hardness. Now Swedish researchers report that men who live in areas where the drinking water has a high content of magnesium are much less likely to suffer a heart attack than are men who live in areas with a low content. Their study involved 854 men who had died from a heart attack between ages 50 and 69 years and 989 age-matched controls who died from cancer during the seven-year study period. All the men lived within a well defined study area in which the drinking water was supplied by 17 different municipal water works. The magnesium content of the water supply varied significantly between the municipalities, but had not changed over a 10-year period. The researchers found that the incidence of fatal heart attacks was 35 per cent lower in areas where the magnesium content of the drinking water was 9.8 mg/liter or more than in areas where the content was 3.5 mg/liter or less. The calcium content of the water was not significantly associated with the incidence of fatal heart attacks. The researchers believe that magnesium protects against fatal heart attacks through its ability to prevent arrhythmias and artery spasms. They also point out that many people are magnesium deficient and that drinking water with a high magnesium content may just be enough to help prevent heart attacks. Magnesium in water is more easily absorbed than magnesium in food. The absorption of magnesium is significantly affected by the simultaneous intake of other nutrients such as sugar, phytates, saturated fats, proteins, calcium, and phosphates.
Rubenowitz, Eva, et al. Magnesium in drinking water and death from acute myocardial infarction. American Journal of Epidemiology, Vol. 143, No. 5, March 1, 1996, pp. 456-62