Heart disease health centre

Over time, as you get older, your arteries naturally begin to harden and get narrower, leading to atherosclerosis. However, there are many factors that can dangerously accelerate this process. These are described below.

High-fat diets and cholesterol

Cholesterol is a type of fat that is essential for the functioning of the body. Cholesterol helps to produce hormones, to make up cell membranes (the walls that protect individual cells) and to protect nerve endings.

There are two main types of cholesterol:

• Low-density lipoprotein (LDL) is mostly made up of fat, plus a small amount of protein. This type of cholesterol can block your arteries, so it is often referred to as 'bad cholesterol'.
• High-density lipoprotein (HDL) is mostly made up of protein, plus a small amount of fat. This type of cholesterol can help to reduce any blockage in your arteries, so it is often referred to as 'good cholesterol'.

Most of the cholesterol that your body needs is manufactured by your liver. However, if you eat foods that are high in saturated fat, the fat is broken down into LDL ('bad cholesterol').

Foods that are high in saturated fat include:

• biscuits
• cakes
• bacon
• sausages
• processed meat
• butter
• cream

The LDL cholesterol sticks to your artery walls in the form of fatty deposits which, over time, gradually build up, narrowing, or completely blocking, your blood supply. The fatty deposits are also known as plaques or atheroma.

As well as a high-fat diet, a lack of regular exercise, being obese and drinking excessive amounts of alcohol can also increase the levels of LDL cholesterol in your body. The medical term for having high cholesterol is hyperlipidemia.

Smoking

Smoking can damage the walls of your arteries. If your arteries are damaged by smoking, blood cells, known as platelets, will form at the site of the damage to try to repair it. This can cause your arteries to narrow.

Smoking also decreases the blood's ability to carry oxygen around your body, which increases the chances of a blood clot occurring.

High blood pressure

If you have high blood pressure (hypertension) it will damage your arteries in the same way as cigarette smoke. Your arteries were designed to pump blood at a certain pressure. If that pressure is exceeded, the walls of the arteries will be damaged. High blood pressure can be caused by:

• being overweight
• drinking excessive amounts of alcohol
• stress
• smoking
• a lack of exercise

See the Health A-Z topic about High blood pressure for more information and advice.

Diabetes

If you have poorly controlled type 1 or type 2 diabetes, the excess glucose in your blood can damage the walls of your arteries.

For more information and advice, see the Health A-Z topics about Type 1 and Type 2diabetes.

Obesity

Being overweight or obese does not directly increase your risk of developing atherosclerosis and cardiovascular disease (CVD), but it does lead to related risk factors that do. In particular, people who are overweight or obese:

• have an increased risk of developing high blood pressure
• tend to have higher levels of cholesterol as a result of eating a high-fat diet
• have an increased risk of developing type 2 diabetes

See the Health A-Z topic about Obesity for more information and advice.

Lack of exercise

As with being overweight or obese, a lack of exercise is not directly related to an increased risk of atherosclerosis and CVD. However, it is linked to an increased risk of being overweight or obese and having high blood pressure (hypertension).

See the Live Well guide to Fitness for more information and advice about exercise.

Alcohol

Drinking an excessive amount of alcohol can cause high blood pressure (hypertension) and raised blood cholesterol levels, increasing your risk of developing atherosclerosis and CVD.

Most heavy drinkers also tend to have other unhealthy habits, such as smoking, eating a high-fat diet and not taking enough exercise.

See the A-Z topic about Alcohol misuse for more information and advice.

Family history

If you have a first-degree relative (a parent, or a brother or sister) with atherosclerosis and CVD, you are twice as likely to develop similar problems compared with the population at large.

Ethnicity

Rates of high blood pressure and diabetes are higher among people of African and Afro-Caribbean descent. This means that people in this group also have an increased risk of developing atherosclerosis and CVD.

People of South Asian descent (those from India, Bangladesh, Pakistan and Sri Lanka) are five times more likely to develop diabetes compared with the population at large. Again, this increases this group's risk of developing atherosclerosis and CVD.

See the Live Well section for more information and advice about health issues that affect black people and those of South Asian descent.

Air pollution

Research that was carried out during 2009 suggested that air pollution, in particular traffic pollution, can cause a slight increase in levels of atherosclerosis.

Researchers found that people living within 50 metres of a major road had higher levels of atherosclerosis than would otherwise be expected.

Glossary

Artery

Arteries are blood vessels that carry blood from the heart to the rest of the body.

Obesity

Obesity is when a person has an abnormally high amount of body fat.

Cholesterol

Cholesterol is a fatty substance made by the body that lives in blood and tissue. It is used to make bile acid, hormones and vitamin D.

High blood pressure

Hypertension is when the pressure of the blood in your bloodstream is regularly above 140/90mmHG.