Cardiovascular health

Why dairy foods are healthy despite their saturated fat content


Dairy foods are high in saturated fats and yet may have a protective effect against cardiovascular disease (CVD). The author of this article explains why the health benefits of dairy products seem to contradict advice in dietary guidelines, and asks whether changing the fat composition of milk and dairy foods would further reduce the risk of CVD.

In the EU, 49 million people are living with CVD which remains a major cause for concern, particularly because of the escalating rates of overweight and diabetes. Dietary guidelines targeting CVD risks have tended to restrict our intake of saturated fats because of their association with raised blood cholesterol. Some proposals have advised restricting dairy foods as they are major sources of saturated fats. However, the author points to recent evidence that indicates such an approach is over-simplistic, and suggests that dietary guidelines should be based on a wider range of markers of CVD risk rather than relying on total cholesterol and low-density lipoprotein cholesterol (LDL-c) levels.

Evidence suggests dairy does not raise CVD risk

Despite their high saturated fatty acids (SFA) content, dairy foods have repeatedly been found to have either no effect, or a beneficial effect on CVD risk, says the author.

Meta-analyses of prospective studies show that drinking a lot of milk does not increase the relative risk of coronary heart disease compared with low milk consumption. Other meta-analyses have shown no increase in CVD risk – and a fall in risk of stroke – per unit increase in milk and cheese consumption. Furthermore, yogurt consumption has been associated with a reduced risk of type 2 diabetes.

The health benefits of dairy may offset the risks from SFAs

The lack of increased risk of CVD among high dairy consumers may be due to the protective properties of other components that counter-balance the effects of SFAs, says the author:

·      Milk and dairy products are rich in micronutrients and proteins, such as whey protein, that have been shown to lower blood pressure.

·      Milk proteins may also have a beneficial effect on blood lipids, although further research is needed to confirm this.

·      Research has suggested dairy product consumption does not increase arterial stiffness, an important predictor of CVD events.

·      The health effect of a food may depend less on the individual effects of its nutrients and more on the overall effect of the food as a whole – the matrix – which determines the fat bioavailability. Evidence suggests the dairy matrix has specific beneficial effects on health.

Different types of dairy seem to be linked to various health effects while different processing methods may enhance interactions in the dairy matrix and so alter the metabolic effects. Hence in a crossover study, cheese did not lower total cholesterol or LDL-c relative to baseline, whereas butter increased both.

What if saturated fats in dairy foods are switched with unsaturated fats?

The author considers whether replacing SFAs in milk and dairy foods with unsaturated fats – cis-MUFA and cis-PUFA – would reduce the risk of CVD while retaining the health benefits gained from the other nutrient content of dairy products.

Studies looking at this question, using total cholesterol and/or LDL-c as markers of risk, have suggested a reduced risk of CVD from dairy foods that have an altered fatty acid profile compared with those with a normal fatty acid content. Further research is underway to clarify the value of this approach.

Find out more: read the original article.

Source: Givens DI. Saturated fats, dairy foods and health: A curious paradox? Nutrition Bulletin, 42, 274–282.