Maintaining a low cholesterol level is undoubtedly beneficial for health, as having a raised bad LDL-cholesterol is closely linked with your future risk of heart attack and stroke which together account for 245,000 deaths each year in the UK.

Although cholesterol levels are often reduced by dietary and lifestyle changes, many people inherit genes that stop them lowering their total cholesterol through diet and exercise alone. Drug treatment is then needed to reduce the risk of premature death, especially in people with other risk factors for heart disease such as smoking, high blood pressure, overweight or diabetes. This is where the group of drugs known as statins come in.

HOW STATINS WORK

Statins (atorvastin, fluvastatin, pravastatin, rosuvastatin and simvastatin) reduce cholesterol production in your liver by inhibiting an enzyme which is involved in the production of both cholesterol and co-enzyme Q10.

Several large trials show that taking statins for at least five years can reduce the risk of coronary heart disease (CHD) by around one third and can reduce overall mortality by approximately a quarter for those who have already had a heart attack1-5M. Taking a statin also reduces the risk of non-haemorrhagic stroke by up to 29% in those with CHD6-7.

Initially, statins were prescribed for people at high risk of coronary heart disease and stroke who had a raised cholesterol level. Then, in 2002, the Heart Protection Study which involved over 20,000 people showed that statins appeared to reduce the risk of major cardiovascular events in everyone, even those with an ideal total c holesterol level of 5.0mmol/l. There did not seem to be a lower cutoff for cholesterol levels beneath which the benefits ended8.

Statins are now recommended for anyone whose likelihood of developing CHD over the next 10 years is 20% or greater. This risk is calculated from charts, based on your gender, age, smoking status, blood pressure, cholesterol levels and whether or not you have diabetes. The general aim of treatment is to lower your LDL cholesterol to 3.0mmol/l and your total cholesterol to 5.0mmol/l, or by 30%, whichever is greater, but the decision to prescribe a statin is no longer based on your cholesterol level alone. This all sounds like good news, so where is the problem?

SIDE EFFECTS

Like all drugs, statins have the potential to cause side effects such as headache, nausea and bowel disturbances. In particular, 1-5% of people taking a statin develop muscle problems such as pain, inflammation and weakness. Out of every 100,000 people taking a statin for a year, one person will also develop a rare condition called rhabdomyolysis, in which muscle fibres break down. If this affects the heart, it is obviously serious, but muscle pigments (myoglobin) entering the circulation can also damage the kidneys.

As well as switching off cholesterol production in the liver, statins also switch off production of co-enzyme Q10 (CoQ10) and this is believed to cause the muscle problems associated with statin drugs9. In fact, the original patent filed for the first statin drug suggested that it should be given together with Co-Q10 supplements to prevent muscle side effects.