The Role Of Diet In The Aetiology Of Coronary Heart Disease

1.0 Summary

The report to discusses the role of diet in the aetiology of Coronary Heart Disease (CHD) and critically assesses the measures the government has taken in trying to reduce death rates from CHD through dietary measures.

Two of the health campaigns the government has been partially successful in are:

• 5-a-day fruit and veg campaign

• 6g of salt campaign

There is a lot of information available from the government but some of it is incomplete and difficult to access unless you are interested in the subject or you actually require the information because you are already at risk.

2.0 Introduction

The purpose of the report is to Discuss the role of diet in the aetiology of Coronary Heart Disease (CHD) and critically comment on the approach that the government has taken in trying to reduce death rates from CHD through dietary measures.

Aetiology is the study of factors of causation or those associated with the causation of disease or abnormal body states (biology-online 2006)

This report will focus on:

• Coronary Heart Disease

• Fats in the diet

• The Dietary Fat Hypothesis

• Salt in the diet

• Antioxidants

• Soluble dietary fibre

• Alcohol and its Effect on Cholesterol

• Government initiatives

3.0 Coronary Heart Disease (CHD)

CHD is caused when the coronary arteries, which supply blood to the heart, become narrower because of the build-up of fatty deposits inside them. This 'furring up' of the arteries is called atherosclerosis.

In time the artery may become so narrow that not enough blood gets through to the heart. This means the heart muscle doesn't get all the oxygen it needs, which is called angina.

If the narrowed artery becomes blocked by a blood clot, this causes a heart attack. (FSA. 2006)

4.0 Fats in the Diet

Fats are insoluble in water, the body uses fats in the formation of cell membranes particularly in nerve cells, it is used transport small amounts of fat soluble vitamins A, D, E, K. Fats are also a source of energy 1 gram provide s 37kJ (9kcal).

The National Diet and Nutrition Survey showed that in 2000/2001, the average daily intake of fat was 87g and 62g for men and women respectively (providing around 36% and 35% of the food energy in the diet).On average women were meeting the recommended target for dietary fat of 35% of food energy. However the survey also showed that saturated fatty acids provide 13% of food energy for both men and women, which exceeded the recommended 11%. The sources of fat are shown in Figure 1. . www.nutrition.org.uk. (2006)

4.1 Saturated and unsaturated fatty acids

All fats contain saturated (containing double hydrogen bonds) and unsaturated fatty acids but are sometimes described as �saturated’ or �unsaturated’ according to the proportions of fatty acids present. For example, butter is often described as a �saturated fat’ because it has more saturated fatty acids than unsaturated fatty acids, while most vegetable oils are described as �unsaturated fats’ as they have more mono- and polyunsaturated fatty acids than saturated. www.nutrition.org.uk. (2006)

5.0 The Dietary Fat Hypothesis

The current dietary fat hypothesis puts forward that raised intakes of foods rich in saturated fat and dietary cholesterol as a percentage of the total energy intake can cause raised levels of Low Density Lipoprotein in the blood stream carrying cholesterol from the liver to the cells, this in turn can cause atherosclerosis. (Daly.2003)

Atherosclerosis are fibro fatty deposits which narrow the coronary arteries that can cause blockages, these blockages if severe can restrict blood flow and prevent clots (thrombus) passing through, this starves the heart of blood which can cause a heart attack.

The theory also includes the role of high-density lipoprotein in the protecting against CHD it is one of the most popular thesis and is used as the basis of many nutritional campaigns within the UK, the impact of monounsaturated and polyunsaturated П‰-3 to П‰-6 fatty acid consuption.

5.1 Cholesterol

Cholesterol is a produced in the liver and taken in though the diet it is essential for the body and it forms part of the membranes of cells. It is carried around the body in the blood by two types of lipoproteins low-density lipoprotein (LDL) and high-density lipoprotein (HDL)

LDL is also often called �bad cholesterol’ because elevated levels in the blood it can be deposited on the walls of the blood vessel causing atherosclerosis

HDL is often called �good cholesterol’ because it retrieves excess cholesterol from body tissues and transfers it to the liver for disposal.

5.2 Saturated