The good, the bad, the facts

The importance of cholesterol levels and the related effect on fitness and longevity are a comparatively recent health issue. Medical wisdom has it that certain types of cholesterol are good for us and other types are not. High levels of some cholesterols can contribute to heart disease and circulatory problems such as hypertension and strokes.

Because of this many medics believe that everyone should monitor their cholesterol levels. Such checks are even more important if a family history of heart disease or strokes exists, or before the age of 65 if related to existing heart problems. Men who are overweight or obese, who smoke, have Diabetes or high blood pressure, have an increased risk of health problems.

The role of cholesterol in disease is not as straight forward as it may first appear. Research has shown that about half of all men suffering heart attacks do not have high cholesterol levels (there is a lot of work looking at the role of inflammation in heart disease). Moreover, some countries with typically high fat diets (e.g. France) also report high levels of cholesterol in the population, yet have low rates heart disease.

What is cholesterol?

Cholesterol is found naturally in the blood stream and body cells. Cholesterol, a soft waxy lipid (fat) that cannot be dissolved in the blood, is important for, amongst other things, cell membrane production and some hormone production. It comes from two sources:

1) We take in fats when we eat animal products such as meat, fish, poultry, eggs, butter, whole milk and cheese. 
2) Our own bodies produce it. Some foods, although they do not contain animal fats may contain trans-fats that cause the body to produce cholesterol.

There are 2 main types of cholesterol:

LDL (low density lipoprotein), considered to be 'bad' cholesterol. This is the type that can block arteries. Cholesterol builds up inside the blood vessel walls in the form of plaques (known as arteriosclerosis). The plaques can restrict blood flow to the heart and if they burst the contents spill out, clots can form and travel around the body in the blood stream. The clots can block the small blood vessels in the heart leading to a heart attack. If they block vessels in the brain they cause a stroke. HDL (high density lipoprotein), considered to be 'good' cholesterol. Research suggests that this type protects the body and reduces the chances of a heart attack.

What should my blood cholesterol levels be?

The best way, the most reliable way of finding out if you have high cholesterol levels, is by having a blood test. Some people who have very high levels of cholesterol do have outward signs. One is called arcus juvenilis, a pale ring around the colored part of the eye (iris) can indicate too much cholesterol in the under 50 year old, the other sign is a yellowish fatty deposit under the skin around the eyes, called xanthelasmata.

Blood test results

Total blood cholesterol:This should be less than 200 mg/dL. If it is then your risk of having a heart attack is low.  If your total blood cholesterol is between 200 to 239 mg/dL then you are at borderline high risk. These levels do not necessarily mean you risk heart or related problems, but you should ask for medical advice to assess your particular health picture. If your total blood cholesterol levels above 240 mg/dL is considered high risk. 20% of Americans are considered to be in this category. If your results are at this level or above then you should ask your doctor if you require any treatment and/or lifestyle changes. 

LDL cholesterol levels: are very important in rating your risk of having a heart attack or a stroke. The lower your LDL cholesterol is, the lower your risk. It is this cholesterol blood result that is seen as the better predictor of health than total blood cholesterol levels. LDL blood cholesterol levels should be less than 100 mg/dL.