Cholesterol - the good the bad and the ugly!

Wednesday 28th April 2010 8:53am

What is cholesterol?

Cholesterol is a fatty substance produced naturally by the body and is found in the cell membranes and transported in the blood plasma of all animals. It is an essential structural component for the function of every cell in the human body. Cholesterol is an important component for the manufacture of bile acids, steroid hormones, and several fat-soluble vitamins. About two thirds of the cholesterol in our blood is made by the liver that is why for some people diet and lifestyle modification can only go so far towards reducing cholesterol. The remainder comes from foods, especially those high in saturated fats.

Good cholesterol and bad cholesterol

BAD - Low density lipoprotein (LDL) cholesterol – carries most of the cholesterol that is delivered to cells. It is called the ‘bad’ cholesterol when its level in the bloodstream is high because that it can contribute to plaques that clog up your arteries.

GOOD - High density lipoprotein (HDL) cholesterol – is called the ‘good’ cholesterol because it helps remove excess cholesterol out of the cells, including cells in the arteries.

What are triglycerides?

When we eat fats in food they form triglycerides that are absorbed into the blood and either burned for energy or deposited into the body's fat stores. High levels of triglycerides often go together with low levels of good (HDL) cholesterol or high levels of bad (LDL) cholesterols.

High triglyceride levels are usually diet related and are the easiest of the three to modify by following a healthy diet and getting plenty of exercise. Typically overeating increases the likelihood of increase triglyceride levels as does moderate levels of alcohol intake.

Why is high cholesterol a problem?

High blood cholesterol is one of the three main risk factors for heart disease. The other two risk factors are cigarette smoking and high blood pressure.

Since cholesterol is essential for all animal life, a certain amount of cholesterol is necessary for the normal functioning of your body. However, high levels in blood circulation, depending on how it is transported within lipoproteins, are strongly associated with progression of atherosclerosis.

Atherosclerosis (also known as arteriosclerotic vascular disease or ASVD) is the condition in which an artery wall thickens as the result of a build-up of fatty materials such as cholesterol. It is commonly referred to as a hardening or furring of the arteries caused by the formation of multiple plaques within the arteries. If one of these plaques ruptures or a piece breaks off it can lodge in a small artery in the heart or brain leading to a heart attack or stroke.

Even if the plaque is stable eventually it might become so large that it partially blocks blood flow through one of the small arteries that feed the heart muscle leading to low oxygenation of that area of the heart. Typically this is worsened by exercise as the heart is in need of more oxygen and angina results.

Does menopause affect my cholesterol?

Yes. Blood cholesterol tends to rise after menopause.

Healthy eating to lower cholesterol

Eating foods that are low in saturated fat is a great way to help cholesterol under control and everyone should make the effort in the first instance. However since 70% of cholesterol in the body is manufactured by the liver from other ingredients diet can only go so far.

Limiting intake of foods that have a high saturated fat content (such as many biscuits, cakes and fatty take-away foods) is a great way to start reducing intake as well as replacing saturated fats in the diet with mono- or poly-unsaturated fats (such as using olive oil instead of butter).

Eating some foods with poly-unsaturated and mono-unsaturated fat (such as nuts, avocados and oily fish) is useful as well as including more fruit, vegetables and wholegrain bread and cereals in your diet (for further information see fibre)

Other ways to reduce cholesterol:

Exercise decreases total cholesterol levels, probably through weight management, but it also appears to increase HDL levels in distance athletes.
Everyone should ideally aim for their ideal weight but even losing a few kilograms can make a big difference to your cholesterol, how you feel and to your exercise tolerance making those morning walks or runs a bit easier and more enjoyable.
Keeping alcohol consumption to moderate levels is essential especially for triglyceride control because while your liver is busy getting rid of alcohol its capacity to clear fats from the blood is reduced and it reduces your weight loss efforts.
Unlike alcohol there is no safe level of smoking so seek help from your doctor or pharmacist to stop. This may also help keep your blood pressure under control. Remember high BP is one of the other key risk factors for heart disease.

Benefits of omega-3 fats

Research is ongoing, but the benefits of omega-3 fats in the diet seem to include that they:

Lower triglyceride levels, which are important risk factors in coronary heart disease
Improve blood vessel elasticity
Keep the heart rhythm beating normally
Thin the blood, which makes it less sticky and less likely to clot
Reduce inflammation and support the immune system
Reduce blood pressure
May play a role in preventing and treating depression
Contribute to the normal development of the foetal brain.

Did you know?

The name cholesterol originates from the Greek chole- (bile) and stereos (solid), and the chemical suffix -ol for an alcohol, as François Poulletier de la Salle first identified cholesterol in solid form in gallstones, in 1769. However, it was only in 1815 that chemist Eugène Chevreul named the compound "cholesterine".

This information is not intended as a substitute for qualified medical advice. Please consult a properly qualified health care practitioner.