Daily Protein Supplements Decrease Blood Pressure Activity

July 19, 2011

Both daily supplements of milk and soy protein effectively decrease blood pressure, and both performed better than carbohydrates in this respect.

According to the results of a randomized clinical trial, both daily supplements of milk and soy protein effectively decrease blood pressure, and both performed better than carbohydrates in this respect.

Both supplements were connected to a 2.3 and 2.0 mmHg reduction in systolic blood pressure in comparison with a refined carbohydrate supplement.

"The systolic blood pressure differences we found are small for the individual, but they are important at the population level," reported study leader Jiang He, MD, PhD, from Tulane University.

According to the researchers, lowering systolic blood pressure by 2 mmHg can potentially result in 6% fewer stroke-related deaths, a 4% lower rate of heart disease deaths, and an overall 3% reduction in deaths nationwide.

These findings, said He, imply that partially replacing refined carbohydrates with foods or drinks high in soy or milk protein may aid in preventing and treating high blood pressure, or hypertension.

The researchers studied 352 participants twenty-two years of age and older with pre-hypertension and stage-1 high blood pressure.

They randomly assigned each participant to be administered either 40 grams of protein from soy or milk daily, or carbohydrate supplementation, both enduring for eight weeks. After the eight week interval, the participants underwent a three-week “wash out” stage before moving over to the other group and repeating the cycle.

The investigators found that soy and milk protein supplementations were connected to a decrease in systolic blood pressure of 2.0 and 2.3 mmHg, respectively; no changes in diastolic blood pressure were found, however, in comparison to the carbohydrate group. Systolic function related to the contraction of the heart, whereas diastolic relates to the filling of the heart with blood.

"Some previous observational research on eating carbohydrates inconsistently suggested that a high carbohydrate diet might help reduce blood pressure," stated He. "In contrast, our clinical trial directly compares soy protein with milk protein on blood pressure, and shows they both lower blood pressure better than carbohydrates."

The researchers wrote 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.”

The study was published under the title “Effect of Dietary Protein Supplementation on Blood Pressure: A Randomized, Controlled Trial” in the journal Circulation.