Does Lifestyle Affect the Development of Coronary Heart Disease?

Cardiovascular Disease (CVD) is Britain’s biggest killer, accounting for 40% of premature deaths. CVD is an umbrella term for several afflictions. These include Coronary Heart Disease (CHD), atherosclerosis and arteriosclerosis, angina, coronary thrombosis and myocardial infarction and stroke. Most heart attacks are caused by atherosclerosis this is caused by the build up of cholesterol in the arteries to form atheromatous plaques. This causes the artery wall to thicken and narrows the lumen. The onset of a plaque can be caused by physical damage to the artery, sometimes caused by high blood pressure. Plaques disturb the flow of blood, causing a clot known as a thrombus. CHD is when the lumen of the two coronary arteries becomes blocked by plaques, reducing the flow of oxygenated blood to the heart. This causes the heart to become oxygen starved. There are two types of CHD- angina and myocardial infarction. Angina is when the heart respires anaerobically, causing a build up of lactic acid in the heart. A myocardial infarction is when a lack of oxygen causes part of the heart to die. When blood arrives in the heart faster than it is passed out heart failure is said to have occurred. An infarction on the left hand side of the heart will cause fluid build up in the lungs, while Infarction on the right hand side will cause build up of blood in the veins and increased pressure in the capillaries.

It has long been assumed that lifestyle factors play an important part in the onset of CHD and that it is a partially self inflicted disease. Numerous factors affect CHD, including diet, age and high blood pressure. I will investigate the consequence of these and other factors on Coronary heart disease. A diet which is high in saturated fat causes a rise in blood cholesterol. ‘A vegetarian "ape-diet", based on the foods our simian cousins eat, is as effective in lowering cholesterol as an established

Cholesterol lowering drug, reveals a new study. High cholesterol levels increase the risk of cardiovascular disease.’(Shaoni Bhattacharya, New Scientist vol.290). Deaths from heart disease in Britain are much higher than deaths in Japan, where people have lower fat intakes and lower blood cholesterol. ‘In 1998, 150 men in every 100,000 died from heart disease in Britain. This compares with 99 per 100,000 in the rest of the EU and just 36 in Japan, which has the lowest rates in the world.’(BBC news, taken from the Journal of Epidemiology and public health). This proves that diet is a major cause of heart disease.

Hypertension, or high blood pressure, is when the arteries narrow causing blood to be pumped through them with too much force causing damage to the artery walls. ‘It is a sign that the heart and blood vessels are being overworked. Untreated, hypertension will cause the heart to eventually overwork itself to the point where serious damage can occur. Hypertensive patients are also at increased risk of heart disease and stroke.’(Ronald D. D\'Agostino, D.O., FACC and Robert I. Hamby, M.D., FACC, FACP, April 15, 2003 Someone with blood pressure of 170/100 has twice the chance of dying of heart disease as someone with normal blood pressure of 120/80.

Smoking can increase the risk of a heart attack. Carbon monoxide and nicotine both damage the walls of the arteries and increase the chances of plaques forming. Nicotine stimulates the production of platelets which increases the chance of a thrombus forming. Nicotine also increases blood pressure and heart rate whilst constricting the blood vessels, putting greater strain on the heart. Also new research indicates that cigarettes may cause an instant heart attack. ‘A team of researchers from Hartford and Boston has found that cigarettes also have an immediate effect. An individual cigarette can actually set off a heart attack. The research was presented in early March at the American Heart Association\'s annual conference on cardiovascular disease epidemiology and prevention in San Antonio. Researchers found that the closer victims were to their last cigarette when their symptoms began, the bigger the heart attack causing blood clot. The study "establishes a link between the act of smoking and the tendency of a blood clot to be formed and create a heart attack,\'\' says Giri. He