What Is Cholesterol?

Cholesterol is a soft, waxy substance that is mainly manufactured by the liver, but it can also be influenced by your diet. It circulates around your body in the bloodstream.

Cholesterol is  essential for your body to function - it is an important building block in the structure of cells and is also used for making hormones and in the production of energy.

Having too much cholesterol in the bloodstream - or a high cholesterol level - is not a disease in itself. However it can lead to other health problems. If you have too much cholesterol in your bloodstream it can build up on the inner artery walls. This can cause the arteries to become narrowed and it may restrict, or even completely block the flow of blood.

This condition is known as atherosclerosis and can significantly increase the risk of heart problems and strokes (depending upon where the restriction is). The diagram below shows how cholesterol can form on the inner artery walls and restrict, or completely block, the flow of blood. 

The cholesterol builds up on the inner artery wall much the same way as plaque forms on your teeth. The result of this will depend upon where the blood flow restriction takes place. It can lead to angina or heart attack or, if the restriction occurs elsewhere, it can lead to a stroke, leg pain, ulcers, infections and even gangrene.

A Brief History of Cholesterol 

Cholesterol has been around as long as we have. However, it's only relatively recently that the medical community has become concerned about it. Why is this?

For reasons which are not yet fully understood, the frequency of Coronary Heart Disease (CHD) in the industrialised nations increased markedly during the 1920's. By 1940, coronary heart disease had become the number one cause of premature death - a phenomenon which was not understood at that time.

In 1950 John Gofman, an American doctor, hypothesised that cholesterol was to blame. Dr. Gofman's theory was not widely accepted at the time but in 1951 pathologists visited Korea to investigate war wounds by conducting autopsies on GIs who had been killed in action and made some remarkable discoveries.

During the course of their studies, which were conducted on a group of men who had an average age of only 22, they were surprised to find evidence of coronary heart disease. Given the young age of the test group, this was an amazing discovery.

They found a fatty substance sticking to the inner artery walls of around 35% of the men tested. By the time the tests were completed they had found evidence of coronary heart disease in over 75% of the test group - young men barely out of their teens.

It was found that cholesterol was present in the material which had built up on the inner artery walls, causing them to become blocked. This was linked with the facts that people who died of heart disease often had high blood cholesterol levels and also that people who suffered from hereditary high blood cholesterol suffered a higher incidence of coronary heart disease - and high cholesterol levels and heart disease became inextricably linked.

Two Sides To Every Story

There are, of course, two sides to every story and it's worth noting that there is a body of opinion which does not agree with the viewpoint that cholesterol is closely linked to coronary heart disease. You can read more about this alternative opinion by clicking here.

However, whichever of the two medical opinions is correct, there can be no doubt that eating a healthier diet, getting more exercise, consuming less alcohol and stopping smoking will be beneficial to your overall health and will allow you to enjoy an active life for longer.

If you are in any doubt about health issues, or if you are concerned about any medication you may be taking, then you should always consult your own doctor or seek specialist medical advice.