CARDIOVASCULAR DISEASE
Cholesterol is a type of fat (lipids) found in blood and a certain amount of cholesterol is needed in the body for cell formation and hormone production. When total cholesterol levels go above the healthy range, it can lead to narrowing and hardening of the arteries and therefore, the risk of cardiovascular disease (CVD) is increased.
Generally, four aspects are considered when assessing someone’s blood lipid profile, namely:
- total cholesterol level
- proportion of high-density lipoprotein (HDL) – also called healthy cholesterol
- proportion of low-density lipoprotein (LDL) – also called bad cholesterol
- level of triglycerides.
In the past, the intake of saturated fat has been associated with an increase in blood lipid levels. Milk and dairy contain more than 400 different types of fatty acid, making milk fat a complex fat. Although the exact composition may vary slightly, almost two-thirds (65%) of the fat in full-cream milk is saturated, a quarter (25%) is monounsaturated and about 3% constitutes polyunsaturated fatty acids.
Current research shows that certain saturated fats, such as those found in dairy and more specifically cheese, have a neutral, and even a lowering, effect on blood lipid levels, such as oleic acid, which is known to have a lowering effect on LDL-cholesterol levels and is, in general, associated with a decreasing CVD risk. This effect is linked to the nature of the milk fat globule membranes, which affect the digestion of dairy products and the uptake of dairy fat (also read about the dairy matrix).
In view of the high prevalence and major implications of hypertension, attempts to decrease blood pressure are justified. A large evidence base has confirmed an association between consumption of dairy products and reductions in blood pressure. The beneficial effect of dairy consumption on blood pressure appears to be derived from its complete nutritional profile and not solely from calcium. The combination of minerals, vitamins, proteins and essential fatty acids, as well as the specific peptide sequences of dairy, contributes to the so-called dairy matrix effect. Fat-free and low-fat dairy products, especially milk, appear to have an even more significant lowering effect on blood pressure than other dairy products. Following the DASH (Dietary Approaches to Stop Hypertension) diet, which focuses on fruit and vegetables and low-fat dairy foods, has been shown to be an effective way to lower blood pressure.
Milk and other dairy products can be eaten daily without increased risk of cardiovascular disease, and may even have a protective effect on heart health. Dairy products in general, as well as their specific components such as found in cheese, have been shown to have a positive effect on non-lipid cardiovascular disease risk factors such as blood pressure, inflammation, insulin resistance and type 2 diabetes, obesity and metabolic syndrome. Saturated fatty acids in milk, specifically oleic acid, are also known to have a lowering effect on low-density lipoprotein cholesterol, and in general are associated with decreasing the risk of cardiovascular disease (also see information on the effect of dairy on cholesterol levels). This effect is due to the milk fat globule membranes that have a significant effect on the digestion of dairy products and the uptake of dairy fat (see information on the Dairy Matrix). It is the MFGM that prevents the negative effects of saturated fatty acids that help contribute to a lower CVD risk. Milk and other dairy products can therefore be eaten every day as recommended by the South African Food Based Dietary Guidelines, without increased risk of cardiovascular disease and possibly even fulfilling a cardio-protective role.