Coronary Heart Disease: Causes, Risks, and Prevention

Posted on Mar 21, 2025 in Medicine & Health

Coronary Heart Disease: Causes and Risk Factors

In coronary heart disease (CHD), the walls of the coronary arteries are gradually damaged by deposits of fats and cholesterol, forming plaque. These deposits are laid down in the artery wall.

The wall becomes stiff, which is why the term ‘hardening of the arteries’ is sometimes used. The medical term for this condition is atherosclerosis.

Although CHD is called a disease, it is likely a natural process of aging. However, it progresses more slowly in women, and some people develop it more than others.

Key Risk Factors for Early CHD Development:

  • Genetic factors
  • High blood cholesterol levels
  • Lifestyle factors

The genetic factor is particularly important. If a person has a father, mother, brother, or grandparents who died early of CHD, there is a possibility that the person will also suffer CHD at an early age.

If a person has a very high cholesterol level in the blood, that person can be at risk of CHD.

Cholesterol in an artery

Lifestyle Factors Linked to CHD:

  • A high-fat diet, especially one rich in saturated fat from animals
  • Lack of exercise
  • Smoking
  • Leading a stressful life

Lifestyle factors linked to CHD

Lack of exercise, Smoking, Diet rich in saturated fat, Leading a stressful life

Consequences of Coronary Artery Damage

There are several possible consequences of the damage done to coronary arteries in CHD. The most common effect is that at some point, an area of plaque can rupture (break open) inside the artery. This causes a blood clot (thrombosis) to form on the plaque’s surface.

If the clot becomes large enough, it can mostly or completely block blood flow through a coronary artery.

The lack of oxygen will stop the cardiac muscle cells from contracting properly, and the portion of the heart muscle fed by the artery begins to die. If the area of muscle affected is big enough, the regular beating of the heart is interrupted, and we say that the person has suffered a heart attack (myocardial infarction).

A less common cause of a heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery. Spasms can occur in coronary arteries that are not affected by atherosclerosis.

Movie 1.3 Heart function and health

The Role of Diet in Heart Disease

Research has shown that our diet, especially the amount and type of fat we eat, can increase the risk of coronary heart disease.

Most foods contain different types of fat: saturated, polyunsaturated, monounsaturated, and trans fats. Some kinds are better for you than others.

Fat is essential in our diet. The important thing is to choose the healthier types of fats and enjoy them in moderation.

Movie 1.4 What happens during a heart attack?

Another consequence of the hardening of an artery is that the artery is more likely to burst at the peak of pressure when a pulse of blood is expelled from the heart.

Blood leaks out of the damaged vessel. The result of this is most severe in the brain, where an area of brain tissue can be killed. This is a stroke.

Healthy Fats

When choosing fats, the best options are unsaturated fats: monounsaturated and polyunsaturated fats.

These fats, if used in place of others, can lower your risk of heart disease by:

  • Reducing total cholesterol
  • Reducing LDL (‘bad’) cholesterol in the body

One type of polyunsaturated fat, omega-3 fatty acids, may be especially beneficial to your heart.

Omega-3s appear to:

  • Decrease the risk of coronary artery disease and may also
  • Protect against irregular heartbeats
  • Help lower blood pressure levels

Best Sources of Healthy Fats:

  • Monounsaturated fat (MUFA) is found in olive oil, peanut oil, avocados, nuts, and seeds.
  • Polyunsaturated fat (PUFA) is found in vegetable oils (such as corn and sunflower oils), nuts, and seeds.
  • Omega-3 fatty acids are found in cold-water fish (such as salmon, mackerel, and herring), tuna, flax seeds, flax oil, and walnuts.

Harmful Fats

Saturated and trans fats (trans-fatty acids) are less healthy kinds of fats. They can increase your risk of heart disease by increasing your total and LDL (‘bad’) cholesterol.

Dietary cholesterol isn’t technically a fat, but it is found in food derived from animal sources. Intake of dietary cholesterol increases blood cholesterol levels, but not as much as saturated and trans fats do, and not to the same degree in all people.

Common Food Sources of Harmful Fats:

  • Saturated fat is found in animal products such as fatty cuts of meat, sausages, bacon, and dairy products (butter, cheese, and cream).
  • Trans fats are found in commercially baked goods such as biscuits, cakes, and pastries, and fried foods such as doughnuts and chips.

Dietary cholesterol is found in animal products such as fatty meats, liver and other organ meats, eggs, seafood, and dairy products (butter).

Antioxidants and Heart Health

Cholesterol is a type of fat known as a sterol and is the main constituent of fatty deposits in blood vessels.

It is deposited in the linings of the arteries when it is oxidized (picks up oxygen circulating in the blood).

Antioxidants found naturally in foods, especially:

  • Vitamin E
  • Vitamin C
  • B-carotene
  • Selenium

Help to stop cholesterol from picking up oxygen so that it is less readily deposited in the coronary arteries and therefore help to avoid coronary heart disease.

Cholesterol in an artery

B-Carotene, Selenium

Sources of natural anti-oxidants Vitamin E, Vitamin C, B-Carotene, Selenium

Exercise and Heart Health

Exercise has many beneficial effects on health:

Exercise Improves the Efficiency of the Heart

  • Regular exercise improves the strength of the heart muscle. The heart of someone who exercises regularly is likely to be able to pump more blood with each heartbeat than the heart of someone who does not exercise.
  • The amount of blood pumped in one beat is called the stroke volume.
  • An increased stroke volume means that the heart can pump enough blood to the body with fewer beats per minute, so the resting pulse rate is lower.
  • Overall, the heart does not have to work so hard. Regular exercise can greatly decrease the risk of suffering CHD.