The Effects of Milk Proteins on Blood Pressure

Rationale: Hypertension is the major controllable risk factor associated with cardiovascular disease. The risk of developing CVD is directly related to blood pressure (BP) level. Tripeptides IPP and VPP obtained from milk proteins were shown to have potential blood lowering effects. The renin-angiotensin system is one of the major pathways of BP regulation, and ACE inhibition is an important target for BP control. CasiGold and CasiMax are hydrolysed casein preparations consisting of relatively high concentrations tripeptides which have ACE inhibitory properties in vitro and which may have beneficial effects on blood pressure.

Study population: 84 female and male Caucasians with a high-normal blood pressure or mild hypertension, aged 30 - 70 years at Day 01 of the study and with a BMI 18 - 32 kg/m2, will participate in the study.

Intervention: All subjects receive all treatments, but in a different order. One of the treatments consists of daily consumption of two capsules Casigold containing IPP during a period of 4 weeks. One of the treatments consists of daily consumption of two capsules Casimax containing a mixture of tripeptides during a period of 4 weeks. And one of the treatments consists of daily consumption of two capsules placebo during a period of 4 weeks. One capsule will be taken upon completion of breakfast and one capsule will be taken upon completion of dinner.

Main study parameters: The main study parameter is the blood pressure after 4 weeks of each treatment. Blood pressure will be measured at the study site on the two last days of each treatment period. Other study parameters include evaluation of safety at the end of each treatment period, and determination of genetic polymorphisms. Analysis of renin and angiotensin I and II will only be done in case a change in BP is found.

Inclusion criteria

• Healthy female and male Caucasians
• Age between 30 and 70 years at Day 01 of the study
• Body Mass Index (BMI) 18 - 32 kg/m2
• Blood pressure: SBP 120-139 mmHg/DBP 80-89 mmHg (pre-hypertension) or SBP 140-159/DBP 90-99 mmHg (stage 1 hypertension)
• Voluntary participation
• Having given their written informed consent
• Willing to accept use of all nameless data, including publication, and the confidential use and storage of all data for at least 15 years
• Willing to accept the disclosure of the financial benefit of participation in the study to the authorities concerned

Exclusion criteria

• Having a history of medical or surgical events that may significantly affect the study outcome, including cardiovascular disease or systolic blood pressure ≥ 160 mm Hg after repeated measurements
• Any concomitant medication, with the exception of paracetamol, that may influence the outcome of the study
• Intolerance or allergy to milk products
• Not willing to give up consumption of >1 fermented dairy product per day
• Alcohol consumption > 28 units/week for males or > 21 units/week for females women)
• Smoking
• Reported unexplained weight loss or weight gain of > 2 kg in the month prior to pre-study screening or during the study
• Reported slimming or medically prescribed diet
• Reported vegan, vegetarian or macrobiotic life-style
• Participation in night shift work
• Pregnant or lactating or wishing to became pregnant in the period of the study
• Not having a general practitioner
• Not willing to accept information-transfer concerning participation in the study, or information regarding a subject's health to and from a subject's general practitioner.