Role of dietary factors in the hypertension of African Americans.

Epidemiological and experimental data suggest that dietary constituents are among the causative factors that contribute to the higher prevalence and severity of hypertension in African Americans as compared with European Americans. Given the difficulty of cleanly separating a change in one dietary nutrient from concomitant changes in others, it has been difficult to reliably attribute an observed effect on blood pressure level and hypertension prevalence to the specific dietary constituent under study. Nevertheless, because hypertension is virtually nonexistent in societies whose dietary sodium chloride intake is very low, it appears that a sodium chloride intake in excess of that required to maintain adequate extracellular fluid volume is necessary but not sufficient for hypertension to be manifest. Additional factors are clearly necessary in the development of hypertension because most individuals, including African Americans, can ingest a high sodium chloride diet without developing hypertension. Evidence for the potential importance of other dietary constituents is also discussed, as are dietary strategies that effectively reduce blood pressure in hypertensive individuals. The data presented support the need for continued research into dietary constituents as potential factors contributing to the etiology of hypertension, as well as effective adjuncts to the management of this very common health problem.