Magnesium in drinking water supplies and mortality from acute myocardial infarction in north west England

Abstract

Objectives-To examine whether higher concentrations of magnesium in drinking water supplies are associated with lower mortality from acute myocardial infarction at a small area geographical level; to examine if the association is modified by age, sex, and socioeconomic deprivation. Design-Small area geographical study using 13 794 census enumeration districts. Water constituent concentrations (magnesium, calcium, fluoride, lead) measured at water supply zone and assigned to enumeration districts. Setting-305 water supply zones in north west England. When adjusted for north-south and eastwest trends in mortality from acute myocardial infarction and for drinking water calcium, fluoride, and lead concentrations, this relative risk was 1.01 (95% CI 0.96 to 1.06). There was no evidence of a protective eVect for acute myocardial infarction even among age, sex, and deprivation groups that were likely to be relatively magnesium deficient. For ischaemic heart disease mortality there was an apparent protective eVect of magnesium and calcium (with calcium predominating in the joint model), but these were no longer significant when the geographical trends were incorporated. Subjects-ResidentConclusions-No evidence was found of an association between magnesium concentrations in drinking water supplies and mortality from acute myocardial infarction. These results do not support the hypothesis that magnesium is the key water factor in relation to mortality from heart disease. (Heart 1999;82:455-460)

Geochemistry of ground water and the incidence of acute myocardial infarction in Finland

“…36 38-44 In some studies an association between CVD and water hardness was not found. [45][46][47][48] Much of the disagreement in earlier studies may be related to the complexity of the ecological analysis and the difficulty to apply results from ecological studies at the individual level.…”

Daily Intake of Magnesium and Calcium From Drinking Water in Relation to Myocardial Infarction

“…Other studies have reported mean magnesium levels above 10 mg/L, calcium levels above 30 mg/L, and hardness above 50 degrees,14,[33][34][35] which has…”

“…10 -13 The evidence is still conflicting, however, and a recently large and detailed geographic study could not confirm these findings. 14 The hardness of drinking water is largely determined by its content of calcium and magnesium. Although both calcium and magnesium have been investigated, the biologic mechanism for a potential protection in hard drinking water has mainly been suggested to involve magnesium.…”

The influence of calcium and magnesium in drinking water and diet on cardiovascular risk factors in individuals living in hard and soft water areas with differences in cardiovascular mortality

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