Hypotensive effects of solitary addition of conventional nonfat dairy products to the routine diet: a randomized controlled trial.

BACKGROUND The high consumption of low-fat and nonfat dairy products is associated with reduced risk of high blood pressure. OBJECTIVE We aimed to investigate whether the solitary addition of nonfat dairy products to the normal routine diet was capable of lowering blood pressure in middle-aged and older adults with elevated blood pressure. DESIGN With the use of a randomized, crossover intervention-study design, 49 adults (56% women) with elevated blood pressure (mean ± SEM age: 53 ± 2 y; systolic blood pressure: 135 ± 1; diastolic blood pressure: 80 ± 1 mm Hg) underwent a high-dairy condition (+4 servings conventional nonfat dairy products/d) and isocaloric no-dairy condition (+4 servings fruit products/d) in which all dairy products were removed. Both dietary conditions lasted 4 wk with a 2-wk washout before crossing over into the alternate condition. RESULTS The high-dairy condition produced reductions in systolic blood pressure (135 ± 1 to 127 ± 1 mm Hg) and pulse pressure (54 ± 1 to 48 ± 1 mm Hg) (both P < 0.05). The hypotensive effects were observed within 3 wk after the initiation of the dietary intervention and in both casual seated and ambulatory (24-h) measurements (P < 0.05). Pulse pressure was increased after the removal of all dairy products in the no-dairy condition (54 ± 1 to 56 ± 1 mm Hg; P < 0.05). There were no changes in diastolic blood pressure after either dietary condition. CONCLUSION We concluded that the solitary manipulation of conventional dairy products in the normal routine diet would modulate blood pressure in middle-aged and older adults with prehypertension and hypertension. This trial was registered at clinicaltrials.gov as NCT01577030.