Diet has been identified as a major contributor to the risk of CVD and in particular high saturated fat intake.
It is now recommended that in order to reduce the risk of CVD we eat a diet containing fruit, vegetables and wholegrain, with moderate intakes of legumes, nuts and low-fat dairy and low in saturated and trans fats, salt and alcohol and that we try to consume high fibre foods and control our sugar intake.
A study that looked at the association between adherence to the Dietary Approaches to Stop Hypertension (DASH) diet (which is low in fat and sodium, and high in fruits, vegetables and low-fat dairy) and the risk of CHD and stroke in women found that women who followed the DASH diet most closely, had a lower risk of CHD and stroke.
Milk and saturated fat
Milk is sometimes linked to increased risk of cardiovascular disease as it is often suggested to have high saturated fat content.
Consumption of saturated fat is linked to increased LDL cholesterol levels, which in turn are linked to increased risk of atherosclerosis and CVD.
Although whole milk has relatively high saturated fat content when compared with certain other foods, lower fat varieties such as semi-skimmed, 1% fat milk and skimmed milks have lower saturated fat content.
It is also important to note that different types of saturated fatty acids have differing effects on LDL cholesterol levels. Some saturated fatty acids such as Stearic acid (in milk and dairy products) actually lower total blood cholesterol and LDL cholesterol levels when compared to other long chain saturated fatty acids.
In addition it is thought that short and medium chain saturated fatty acids have little effect on elevating blood cholesterol levels.
Therefore although milk fat contains a comparatively high proportion of saturated fatty acids, its content of Stearic acid and short and medium chain fatty acids is suggested to minimize the expected increase in blood cholesterol compared with other foods.
In fact, a study involving healthy young men fed a 30% total fat, 9% saturated fat diet indicated that saturated fat from dairy foods raised blood cholesterol less than from meat and coconut oil (known to be high in saturated fat).
Milk and trans fatty acids
Trans fatty acids occur naturally in small amounts in milk and milk products. They are created in the stomach of ruminant animals (such as cows and sheep) when animals consume PUFAs of plant nature and convert them into trans fatty acids by bacteria in the stomach.
Trans fatty acids; also known as hydrogenated fats, are also produced artificially and are present in many processed foods such as margarines, pies, cakes, biscuits and pastries.
Whilst industrially produced trans fatty acids appear to be metabolised in the same way as saturated fatty acids and have been linked to possible health problems such as coronary heart disease, naturally produced ones from ruminant animals have not.
In fact one study involving healthy men compared blood cholesterol levels after consumption of a diet high in natural trans fatty acids with blood cholesterol levels after consumption of a diet high in industrially produced trans fatty acids and found that those consuming the natural trans fatty acids had more favourable blood cholesterol levels.
Cheese and saturated fat
Cheese, particularly hard cheeses are high in fat and saturated fat and for this reason the inclusion of cheese in the diet has generally been associated with an increased risk of cardiovascular disease. However there is now increasing evidence to suggest that there is not an association between moderate cheese consumption and CVD risk factors.
Milk and CLA
Conjugated Linoleic Acid (CLA) refers to a specific type of fat found in milk and dairy products.
This fat has been suggested to reduce the risk of heart disease, benefit the immune system and may have a positive influence on bone health and body composition and reduce the risk of diseases such as cancer.
The benefit of CLA to cardiovascular health may be due to a possible favourable effect of CLA on blood cholesterol levels. Several studies have shown that CLA improves blood cholesterol levels and does not have an affect on risk markers of CVD.
Milk and Calcium
Milk and dairy foods provide calcium, potassium and magnesium amongst other essential nutrients.
Studies have suggested that these nutrients may protect against CHD through beneficial effects on blood lipids and blood pressure.
More specifically, increasing calcium intake has been demonstrated to lower blood total cholesterol and levels of LDL cholesterol.
Strong evidence from scientific studies has also shown that a higher consumption of milk is linked to a lower risk of stroke and heart disease in men and women.
A study in Welsh men found that those who drank the most milk had fewer heart attacks than those who had little or no milk in their diets. The results of this study prompted the authors to conduct an overview of some of the published studies on milk and heart disease in the UK, the USA, Japan and the Netherlands. The overview found that men who had the highest intakes of milk had the lowest rates of heart disease.