Posted on Aug 16, 2011, 6 a.m.
Daily supplements of milk and soy protein lower systolic blood pressure by 2.3 and 2.0 mmHg, respectively.
High blood pressure (hypertension), defined as having a systolic and diastolic blood pressure (BP) greater than 140 and 90 mmHg, is a major risk factor for cardiovascular disease – the leading cause of death among the American population. Jiang He, from Tulane University (Louisiana, USA), and colleagues recruited 352 people, ages 22 and over, who were diagnosed with pre-hypertension and stage-1 high blood pressure. The team randomly assigned each subject to receive either 40 grams per day of protein from soy or milk, or carbohydrate supplementation, each for eight weeks. After each intervention, the participants went through a three-week wash out period before crossing over to a different group. Results showed that soy and milk protein supplementations were associated with reductions in systolic blood pressure of 2.0 and 2.3 mmHg, respectively, but no changes in diastolic blood pressure, compared with the carbohydrate group. Writing that: “The results from this randomized, controlled trial indicate that both soy and milk protein intake reduce systolic [blood pressure] compared with a high-glycemic-index refined carbohydrate among patients with prehypertension and stage 1 hypertension,” the team submits that: “These findings suggest that partially replacing carbohydrate with soy or milk protein might be an important component of nutrition intervention strategies for the prevention and treatment of hypertension.”
Jiang He, Marion R. Wofford, Kristi Reynolds, Jing Chen, Chung-Shiuan Chen, Leann Myers, et al. “Effect of Dietary Protein Supplementation on Blood Pressure: A Randomized, Controlled Trial.” Circulation, July 18, 2011.