Hypertension: heavy metals, useful cations and melanin as a possible repository.

Popular belief has often attributed the disproportionate occurrence of hypertension in blacks to the increased social stresses faced by the minority population. Evidence now points to a more biologically relevant explanation of black hypertension, an increase in levels of heavy metals. Preferentially bound to melanin, cadmium, lead, and copper have implications not only in the etiology of black hypertension, but in the etiology of all hypertension. Of course, hypertension is heterogeneous by nature and cannot be attributed solely to any single cause. However, the indictment of the heavy metals, as well as a deficiency of other cations such as calcium, magnesium, and potassium, warrants a more nutritional approach and less reliance on current pharmacological therapy in selected cases. Melanin should be investigated as a storage bank for useful cations. If real, such a cation reservoir would explain the heat tolerance capacity of blacks and other dark-skinned tropical races.