Recent developments in the etiology and treatment of hypertension: dietary calcium, fat, and magnesium.

Dietary calcium, magnesium, and polyunsaturated and saturated fat have each been implicated as being important factors in the development and treatment of hypertension. Although the mechanisms underlying the relationship between calcium and blood pressure are not clearly defined, calcium supplementation may be effective in lowering blood pressure in certain calcium sensitive subgroups. Dietary polyunsaturated fat intake as a source of linoleic acid may be important in the production of prostaglandins, which are known to modify blood pressure levels. Available evidence indicates that an increased intake of polyunsaturated fat relative to saturated fat may have a hypotensive effect in individuals with borderline hypertension. The mechanisms by which magnesium modifies blood pressure are thought to be both direct and indirect, probably interacting with other electrolytes known to affect vascular smooth muscle tone such as sodium, potassium, and calcium. There is insufficient information from human studies to conclude that magnesium supplementation will lower blood pressure levels.