The Big Question: Are statins really a wonder drug, and should we all be taking them?

Why are we asking this now?

Statins, the cholesterol-lowering drugs, are known to cut the risk of heart disease and are already prescribed to millions of people at high risk. This week a trial of rosuvastatin, whose brand name is Crestor made by AstraZeneca, was shown to dramatically reduce the risk even in people whose cholesterol level was normal or low.

Researchers had expected a reduction of around 25 per cent but the actual decline in risk among the treated group was almost twice that (47 per cent). The results, published in the New England Journal of Medicine, were so clear that the trial of 18,000 patients in 26 countries was stopped early so that all those on placebo could be offered the drug.

What does this mean for the average man and woman?

British researchers have said the findings suggest that anyone with a cholesterol level above 4 mmols per litre should be taking a statin. That equates to 20 million people in Britain and implies medication on an industrial scale.

Statins are already one of the most widely prescribed drugs taken by about four million people in Britain. The National Institute for Clinical Excellence (NICE) said in guidance issued last May that all adults aged 40 to 75 should have their health assessed and those with at least a 20 per cent increased risk of a heart attack within the next 10 years offered treatment. Age, family history, smoking, diet and exercise all affect risk as well as cholesterol level.

Why does cholesterol matter?

Cholesterol is a fatty substance carried in the blood, essential for making and repairing cells. However, high levels increase fatty deposits on the artery walls, leading to artery narrowing. This is a particular problem in the coronary arteries supplying the heart itself because they are narrow to start with. When a blood clot becomes lodged in the narrowed coronary artery, causing a blockage, it starves the muscle beyond the blockage of oxygen, causing a heart attack.

Can't cholesterol be lowered by diet?

Up to a point. This is the first line of defence recommended by doctors when patients are discovered to have high cholesterol. Switching to a low-fat diet, cutting out red meat, cheese, butter and dairy products, and increasing fruit and vegetables can help reduce cholesterol. But cholesterol is also produced by the liver, which is genetically determined and is not subject to individual control. For people with naturally high levels of cholesterol, unrelated to diet, statins may be the only answer.

Does this latest trial tell us anything new?

Yes and no. The size of the effect – a 50 per cent reduction in risk – even for those with normal or low cholesterol, is undeniably impressive. The patients in the trial were selected for high levels of C-reactive protein, which increases heart disease risk and may have contributed to the strong result. But it was already known that lowering cholesterol cuts the risk of heart disease, regardless of the starting level, and that the size of the reduction in risk is in proportion to the amount by which the level was lowered. So in theory everyone could benefit from taking a statin.

If we already knew the benefits, why do the trial?

The market for statins is crowded with products, and competition is fierce among the drug companies for a share of the multibillion global market. The current brand leader is atorvastatin, whose brand name is Lipitor made by Pfizer, which is the most powerful statin with the biggest cholesterol lowering effect.

Many trials can be classed as marketing trials – attempts by the companies to find a small advantage for their drug sufficient to knock the brand leader off its perch.

Have statins been successful?

Yes. They have been described as wonder drugs because they have a dramatic impact in lowering heart attack and stroke yet have few side-effects. Deaths from heart disease and stroke fell 44 per cent in the decade to 2007 and have already exceeded the target 40 per cent reduction set by the Government for 2009-11, partly due to increased prescribing of statins, which are estimated to prevent around 10,000 deaths a year.

Should we all be taking statins?

Some people think so – notably the Government's heart czar, Professor Roger Boyle. Prof Boyle suggested last year that every man over 50 and every women over 60 should be offered a daily statin. This would be simpler than assessing individual risks, which imposes a huge burden on GPs, and is difficult to do.

One third of people who have a heart attack have no warning symptoms and a third of those will die. Prof Boyle, who takes a statin himself, accepted at the time that the public was not ready for a move that would turn millions of "healthy" people into patients, and called for a debate on the pros and cons of mass medication.

This week's results from the latest trial will only add to the pressure for that debate.

Can mass medication ever be justified?

There is a natural resistance to the idea that everyone needs drug treatment. But despite recent falls, heart disease is still a leading cause of death. We accept mass medication in the form of vaccination, folic acid for pregnant women (to prevent birth defects) and fluoride in toothpaste (against dental decay). It may be time to discard the idea that risk factors have to be measured and accept that everyone is at risk.

On the other hand, the prescription of a statin, with its implication that we are at risk of heart disease, may the first intimation of our own mortality. It is not surprising if people want to put that off.

Do statins haveside-effects?

Yes, but they are mostly minor. There are recognised effects on the liver and muscles which may need to be monitored. In rare cases the drugs can cause rhabdomyolysis, a potentially life-threatening condition in which the muscles break down causing kidney failure. But this can be avoided by stopping the drugs if the muscles start to ache.

Some patients complain that statins cause depression but doctors say there is no evidence for this. They say that diagnosing someone at risk of heart disease is the more likely cause of the depression.

Do statins have other benefits?

Yes. A study earlier this year suggested that they halved the risk of dementia. It is thought that, by preventing the build-up of cholesterol, the drugs reduce formation of the fatty plaques in the brain that are thought to be the cause of some types of dementia.

If true, a drug that prevents two of the greatest threats to human health and happiness in the 21st century sounds pretty irresistible.

Should all over-50s be taking statins?

Yes

*They have been around for 20 years and are safe, effective, and have few side effects

*They cut the risk of heart attacks by up to a half, even in those who do not have high cholesterol

*They may also reduce the risk of dementia by curbing the build-up of fatty plaques in the brain

No

*Mass medication of the population may have damaging effects by designating healthy people as sick

*It is still too early to know if the benefits of the drugs outweigh the harms in people at low risk

*Prescribing the drugs for life to millions of "healthy" patients would be prohibitively costly for the NHS

j.laurance@independent.co.uk