Cholesterol and its relationship with health is a hugely complicated topic. To date, the exact function and optimum level of cholesterol is not comprehensively understood.
What's more, renowned researchers still debate over the specific dietary recommendations to "optimise" cholesterol levels in the body.
This week's article, the first of a two-part series, will focus on defining cholesterol and the consequences of cholesterol imbalance.
WHAT IS CHOLESTEROL?
Cholesterol is a tiny organic molecule that presents as a soft, waxy substance in the body. It can be consumed through the diet, but the vast majority of cholesterol present in the body is produced mainly by the liver (approximately 75pc).
Cholesterol is required for numerous functions, including cell protection, hormone production and the making of bile. In fact, cholesterol is so important that if you didn't eat any cholesterol-containing foods, your body would still produce enough of it to carry out these vital functions.
A huge number of factors such as genetics, nutrition, exercise and other lifestyle factors can influence the type and amount of cholesterol in the body.
GOOD AND BAD CHOLESTEROL
Part of the confusion surrounding cholesterol in diet and health is that there are many types of cholesterol with different functions and different meaning in terms of disease risk.
High-density lipoprotein (HDL) cholesterol is often referred to as "good" cholesterol, and so having higher amounts is suggested to help protect the cardiovascular system.
Low-density lipoprotein (LDL) cholesterol is considered the "bad" cholesterol, with very-low-density lipoprotein (VLDL) cholesterol linked to a greater risk of arteriosclerosis and cardiovascular disease.
Because of their hydrophobic nature (resistance to water), cholesterol cannot freely travel in the bloodstream by itself and must be transported in tiny packages called lipoproteins (lipid and protein).
When cholesterol is measured in the blood, a measurement is usually taken of the total cholesterol being transported by HDL or LDL.
However, when assessing the health-risk-associated cholesterol levels in the body, it is not just the amount (number) of cholesterol present that is important but also the size (density) of the molecules.
If you want to prevent or lower the risk of developing atherosclerosis, you must aim to reduce the number of LDL cholesterol and, in particular, VLDL particles circulating in the blood.
WHAT'S THE PROBLEM?
As I have already stated, cholesterol is vitally important for multiple functions in the body, so when or why does the problem occur?