Soy lowers blood pressure

One of the major risk factors of heart disease is hypertension, also commonly known as high blood pressure. Hypertension affects around six million South Africans; that's more people than the total population of New Zealand, including their expected international visitors for this year's Rugby World Cup. Of those South Africans affected, only 26% of men and 51% of women are aware that they have the condition¹.

If left untreated, hypertension may lead to blindness, kidney failure, heart attack, stroke and potentially death. What's more, deaths caused by heart and blood vessel diseases among South Africans aged 35-64 years are expected to increase by 41% between 2000 and 2030¹.

The right direction in improving heart health

However, if you thought ditching your afternoon cappuccino or soy latte would be a step in the right direction to improving your heart health, think again. The results of a new study, recognised by the American Heart Association and published in the August edition of Circulation, suggest consuming soy protein or low-fat milk protein may help to reduce blood pressure.

The study involved three intervention phases and included 352 adults with pre-hypertension. Participants were divided into three groups and received 40g daily of soy protein, low-fat milk protein or a complex carbohydrate supplement over an eight week period. A three-week washout period was implemented in between each intervention phase to allow for the administered product to be eliminated from the body. Researchers found that compared with carbohydrates, supplementation with soy protein and low-fat milk protein was significantly associated with a reduction in systolic blood pressure (the top number in a blood pressure reading).

Professor Brian Rayner, head of the division of hypertension at the Groote Schuur Hospital and University of Cape Town said, "It is well accepted that low-fat dairy products and protein-rich soy foods may be included as part of a healthy diet and lifestyle programme. However, the results of this study go even further, suggesting replacing a portion of your carbohydrate intake with foods that are rich in soy and milk protein appear to have additional benefits of reducing systolic blood pressure by about 2 mmHg."

Improving cardiovascular function

He continues, "Even a small reduction in systolic blood pressure will help to improve overall cardiovascular function and reduce the risk of serious life-threatening cardiovascular events. However the use of soy and milk protein in patients with established hypertension should be discussed with their respective health professionals in conjunction with comprehensive lifestyle modifications and antihypertensive therapy advocated by the South African Hypertension Society."

Dr. Ratna Mukherjea, global applied nutrition lead at Solae, said, "Soy protein is the only nutritionally complete plant-based protein available. Soy is also low in fat, cholesterol-free, as well as environmentally sustainable and economically efficient". If you're a little unsure of how to include soy protein into your diet Dr. Ratna suggests making a delicious soy smoothie for breakfast, including a cup of edamame beans in your salad at lunchtime or snacking on a nutritional soy-protein bar in between meals.

View the study on Hypertension.

References

1. Steyn, K. Department of Medicine, University of Cape Town & Chronic Diseases of Lifestyle Unit, at the Medical Research Council (2007). The Heart and Stroke Foundation South Africa: Heart Disease in South Africa (Media Data Document). [Retrieved on 15 September, 2011 from: http://www.heartfoundation.co.za/docs/heartmonth/HeartDiseaseinSA.pdf].

2. He, J., Wofford M. R., Reynolds, K. et al, 2011. 'Effect of Dietary Protein Supplementation on Blood Pressure: A Randomized Controlled Trial', Circulation. 124:589-595.

3. Government Gazettes of South Africa. Regulation Gazette: No 30075 of 20-Jul-2007, Volume 505 No 8718. [Retrieved on 26 September 2011 from: http://www.google.co.za/search?sourceid=navclient&ie=UTF-8&rlz=1T4RNRN_enZA433&q=2.3.+Government+Gazettes+of+South+Africa.++Regulation+Gazette%3a++No+30075+of+20-Jul-2007%2c+Volume+505+No+8718.+].