Dairy products, calcium, and blood pressure

The previously reported inverse association of dietary calcium intake and blood pressure levels was examined in a Southern California community, in order to determine whether this association was independent of age, obesity, and alcohol consumption. In the total population significantly less calcium intake from milk was reported in hypertensive versus normotensive men (but not women) and the association was independent of age and obesity. In a 23% subsample of men from this cohort the effect of total dietary calcium intake from all dairy products was estimated from a 24-h dietary recall. Again hypertensive men consumed significantly less calcium than normotensives. In men, both systolic and diastolic blood pressure levels were inversely associated with calcium intake from dairy products. After controlling for age, obesity, and alcohol, diastolic blood pressure was negatively and significantly associated with total calcium intake from dairy products, while systolic blood pressure was similarly associated with whole milk calcium alone. Although these data are cross-sectional, they suggest that some component of dairy products, probably calcium, exerts a protective effect against hypertension, and are compatible with the protective effect of calcium reported in hypertension-prone rats.