Blood pressure as the name suggests is the force of blood against arterial walls. A normal adult blood pressure is below 120/80. High blood pressure has been defined as over 140/90. Hypertension or high blood pressure is a major risk factor for the development of cardiovascular diseases, which are the leading causes of morbidity and mortality in western society. It is estimated that 20% of the world’s adult population suffers from hypertension. Hypertension (high blood pressure) is a primary risk factor for heart disease, which affects 25% of the U.S. population and is a major contributor to stroke and heart failure.

Aging is one of the reasons for high blood pressure as arteries loose elasticity. Blood pressure is also controlled by a number of metabolic systems including the major pathway called the renin-angiotensin system (RAS). In the kidneys, this sytem secretes an enzyme called angiotension-converting enzyme (ACE). This results in blood vessel constriction and elevated blood pressure. Inhibitors of the ACE enzyme in blood vessels are a major class of antihypertensive medications that are prescribed to control high blood pressure. Individuals with high blood pressure are often prescribed drugs such as Zestril, Capoten and Vasotec, which block the effects of ACE and thus bring in control the high blood pressure.

However, several adverse side effects such as hypotension, reduced kidney function, coughing and skin rashes have been associated with synthetic ACE inhibitors. Natural inhibitors of ACE have been identified in a variety of food proteins. In particular, milk proteins contain ACE inhibitory peptides (ACE-IP) that can be released by enzymatic hydrolysis either during gastrointestinal digestion or during food processing. It is well established that in vitro incubation of milk proteins with the gastrointestinal proteases pepsin, trypsin and chymotrypsin results in the release of ACE-IP. Hence, it is likely that ACE-IP is generated during normal gastrointestinal digestion. Bacterial and plant proteins can also be used to release ACE-IP. Therefore, hydrolysates of milk protein, caseinates, whey proteins and fractions enriched in individual milk proteins are potentially good sources of ACE-IP.

Diet:
A diet known as Dietary Approaches to Stop Hypertension (DASH) is now recommended as an important step in managing blood pressure. This diet is not only rich in important nutrients and fiber but also includes foods that contain far more electrolytes, potassium, calcium, and magnesium. It makes the following recommendations:

- Avoid saturated fat (although include calcium-rich dairy products that are non- or low-fat).

- When choosing fats, select monounsaturated oils, such as olive or canola oils. (One study reported a reduced need for anti-hypertension medication in people with a high intake of virgin olive oil, but not sunflower oil, a polyunsaturated fat.)

- Whole grains are better option over white flour or pasta products.

- Fresh fruits and vegetables should be consumed every day. Many of these foods are rich in fiber, which may help lower blood pressure. Important foods include most fruits (especially potassium-rich fruits including bananas, oranges, prunes, and cantaloupes) and vegetables (especially carrots, spinach, celery, alfalfa, mushrooms, lima beans, potatoes, avocados, and broccoli). Include nuts, seeds, or legumes (dried beans or peas) daily.

- Choose modest amounts of protein.

Thus proteins that are important for bodybuilding and synthesizing enzymes are also important requirement for individuals with high blood pressure. Proteins, especially milk proteins like whey and casein, can help in lowering high blood pressure.

Whey protein:
Whey is a milk protein containing peptides called lactokinins. Whey contains approximately 20% of original milk proteins. Whey protein (also known as "lactalbumin") constitutes 18% of cow milk and 67% of human milk protein (which are 82% & 33% casein, respectively). These have recently been shown to be mild ACE inhibitors in vitro. Although they do not have the capacity comparable to drugs used for treatment of high blood pressure, they are naturally occurring proteins that help in lowering blood pressure. Latest data also suggests that whey protein hydrolysates result in reductions of systolic blood pressure (a transient pressure peak when the heart is contracting and forcing blood through the arterial system) and diastolic blood pressure (the sustaining pressure in the arterial system when the heart is filling with blood). Also, no side effects have been reported about these proteins. Whey protein is a soluble, easy to digest protein and is efficiently absorbed into the body.

Casein protein:
Caseins are a family of phosphoproteins synthesized in the mammary gland. Its ingestion has an important effect to preserve activity and aid in absorption of other biologically active peptides. Numerous rat studies demonstrate the hypotensive effects of milk-derived ACE-IP. However, only a limited number of human studies have been conducted to date. Initially it was demonstrated that 20g/day of a tryptic hydrolysate of casein resulted in significant reductions in both systolic (SBP) and diastolic (DBP) in hypertensive subjects. More recently, a tryptic hydrolysate of casein containing specific residues of as1-casein peptide could also reduce blood pressure in hypertensive subjects.

These studies provide impressive optimism about the beneficial role of dairy protein peptides in the management of high blood pressure. Thus, individuals with high blood pressure can not only meet their protein requirements with help of whey and casein, but they may also reduce their blood pressure. Individuals with high blood pressure should consult their physician about these milk protein supplements to be included in their diets.

About Protica

Founded in 2001, Protica, Inc. is a nutritional research firm with offices in Lafayette Hill and Conshohocken, Pennsylvania. Protica manufactures capsulized foods, including Profect, a compact, hypoallergenic, ready-to-drink protein beverage containing zero carbohydrates and zero fat. Information on Protica is available at http://www.protica.com 

You can also learn about Profect at http://www.profect.com 

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References

1. Am J Clin Nutr 2000 Jun; 71(6): 1536-1544.

2. Lactokinins: whey protein-derived ACE inhibitory peptides. Nahrung 1999 Jun; 43(3): 165-7.

3. V. Vermeirssen, J. Van Camp, K. Decroos, L. Van Wijmelbeke & W. Verstraete (2003). The impact of fermentation and in vitro digestion on the formation of ACE inhibitory activity from pea and whey protein. Journal of Dairy Science, 86(2), 429-438.

4. V. Vermeirssen, B. Deplancke, K.A. Tappenden, J. Van Camp, H.R. Gaskins & W. Verstraete (2002). Intestinal transport of the lactokinin Ala-Leu-Pro-Met-His-Ile-Arg through a Caco-2 Bbe monolayer. Journal of Peptide Science, 8(3), 95-100.