Biology - Diet and Coronary Heart Disease

Health risks caused by obesity:

Severe obesity can cause the risk of mortality (death). Up the 30000 deaths a year in the UK are considered to be obesity-related. Obesity is thought to be the most important dietary factor in the following health problems:

·         Cancer

·         cardiovascular disease

·         type 2 diabetes

Obesity is linked to:

·         gallstones

·         osteoarthritis

·         high blood pressure (hypertension)

Other components of the diet:

The overall energy intake must be balanced with energy use to avoid becoming overweight or underweight. However, there are many other aspects of the diet that can affect your health. Here, we are concerned with components that may affect the risk of coronary heart disease (CHD)à result of deposition of fatty substances in the walls of the coronary arteries. The deposition is known as atherosclerosis. Deposition is coronary artery walls narrows the size of the lumen à restricts blood flow to heart muscle, which may cause oxygen starvation.

Some components of the diet help reduce the risk of CHD. Dietary fibre, moderate alcohol consumption and eating oily fish all appear to be beneficial. However, more is known about those components of the diet that increases the risk of CHD.

Salt

Excess salt in your diet will decrease water potential of your blood. As a result more water is held in the blood and the blood pressure increases. This can lead to hypertension. Hypertension is a condition in which the blood pressure and particularly the diastolic pressure that is maintained at a level that is too high. Hypertension can damage the inner lining of the arteries, which is one of the early steps in the process of atherosclerosis.

Fats (lipids)

Fats are an essential part of the diet. On any food label the nutritional information will tell you how much fat is present in the food and how much of that is “saturated”. Animal fats tend to be saturated and plant oils tend to be unsaturated. In general it is recognised that saturated fats are more harmful than unsaturated fats. Polyunsaturated fats and monounsaturated fats, such…