July 19, 2011
Soy and Milk Lower Blood Pressure
(Ivanhoe Newswire) "“ Almost 75 million Americans have high blood pressure, a silent killer that can cause heart attacks, heart failure, strokes, kidney damage and other potentially fatal events. Soy/milk protein dietary supplements were associated with lower systolic blood pressure, according to this study.
The study's results suggest that partially replacing refined carbohydrates with foods or drinks high in soy or milk protein may help prevent and treat high blood pressure, Jiang He, M.D., Ph.D., lead researcher of the study, was quoted as saying.
The randomized, controlled clinical trial is the first to document that milk protein lowers blood pressure for people with pre-hypertension and stage-1 high blood pressure.
Systolic blood pressure is the top number in a blood pressure reading and gauges the pressure when the heart contracts.
"Some previous observational research on eating carbohydrates inconsistently suggested that a high carbohydrate diet might help reduce blood pressure," said Dr. He, an epidemiologist at Tulane University School of Public Health and Tropical Medicine in New Orleans, La. "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."
Participants were age 22 or older, with systolic blood pressure ranging from 120 to 159 mmHg and diastolic blood pressure from 80 to 95 mmHg. Each was randomly assigned to take 40 grams of soy protein, milk protein or a refined carbohydrate supplement every day, for eight weeks each.
Each eight-week phase was followed by a three-week washout period when study participants did not take supplements. Blood pressure readings were taken three times at each of two clinical visits before and two clinical visits after each eight-week phase, yielding a net blood pressure change for each supplement period. The study results showed no decrease in diastolic blood pressure.
"The systolic blood pressure differences we found are small for the individual, but they are important at the population level," Dr. He said.
Based on previous research, a 2 mmHg decrease in systolic blood pressure could lead to 6 percent fewer stroke-related deaths, a 4 percent lower rate of heart disease deaths and a 3 percent reduction in overall deaths among Americans.
SOURCE: Circulation: Journal of the American Heart Association, published online July 18, 2011