Cholesterol is a type of fat 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 there are two categories of cholesterol; good (HDL) and bad (LDL). The intake of saturated fat has been associated with increased cholesterol levels. Milk fat is but one of the fats, albeit a complex fat, that forms part of a typical diet. The composition of milk fat may vary slightly, depending on factors such as the race of the animal, the production season, the geographical area in which the animal is kept, the lactation cycle of the cow and the composition of the cow’s diet. Almost two-thirds (65%) of the fat in full-cream milk is saturated, a quarter (25%) is monounsaturated and 3% constitutes poly-unsaturated fatty acids. Saturated fat generally contributes to higher cholesterol levels, yet each saturated fat is different and varies in its ability to increase blood cholesterol. Research has shown that certain saturated fats have a neutral, and in some cases even a lowering, effect on cholesterol levels. The saturated fatty acid in milk, oleic acid, is known to have a lowering effect on blood cholesterol levels.
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 the complete nutritional profile of dairy products and not solely from calcium. The combination of minerals, vitamins, proteins and essential fatty acids, as well as the specific peptide sequences of dairy contribute to this 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. 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 cardio-protective effect. Dairy products in general, as well as their specific components, 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. These findings suggest cardiovascular benefits of dairy foods that go beyond blood lipids. 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.