The Truth about Cholesterol
Next in our series of fitness tips from Personal Trainer, Helen Kukor is cholesterol.
Cholesterol is a large lipid molecule that has no calories so therefore cannot be used by the body as a source of energy. However it is essential to our bodies as it is used extensively to structure tissue and perform functions that are vital to our lives. Four functions of cholesterol are:
- It’s a vital component of cell membranes
- Produces steroid hormones
- Synthesis of bile acids
- Synthesis of vitamin D
Our body is able to synthesize 75-80% of our body’s supply thus making dietary cholesterol a relatively minor requirement. It works in a swing system whereby if dietary cholesterol intake is low, the body will produce higher amounts and the body will produce less cholesterol if dietary intake is high.
Like fat molecules, cholesterol molecules are lipids which means that they don’t attach to the water molecules in the blood. Therefore the body has had to develop protein based ‘carriers’ called lipoproteins that surround cholesterol molecules to transport them around the body. There are three key types of lipoproteins:
- Very low density lipoproteins (VLDL) – These are synthesized in the liver and contain both cholesterol and triglycerides.
- Low density lipoproteins (LDL) – These are formed from VLDLs once they have unloaded most of their triglycerides. They transport the remaining cholesterol to cells in the body that are most in need.
- High density lipoproteins (HDL) – These are synthesized by the liver and transport excess cholesterol from the tissues and blood back to the liver.
It is a well known fact that high levels of cholesterol increase the risk of heart disease. Therefore measuring the level of cholesterol in the blood has become a key marker in the pathology of cardiovascular disease. In particular elevated levels of total triglycerides, elevated LDL cholesterol and lower than 25% HDL cholesterol have all been proven to increase the risk of cardiovascular problems. IN the UK the level identified in the mid 1980’s as the desirable upper limit was a total cholesterol level of 5.2mmol/dL. Levels found above this will initiate the medical profession to intervene with lifestyle changes such as diet plans and exercise and in extreme cases with medication.
If you are worried about your cholesterol levels please consult your doctor or for advice on nutrition and exercise please see a member of our Fitness Team. Find out more about our Personal Trainers and the gym.