Preventive medicine focuses on encouraging the general public to worry about illnesses that they will probably never develop, and on doctors to search for remedies that they may never need. But it saves lives. The number of British men and women dying prematurely from heart attacks has fallen by almost a third over the past decade and much of the credit must go to the increasingly widespread use of the statin family of cholesterol-lowering drugs.

Statins are taken by millions of people in the UK and are one of the key ingredients in the polypill (a collection of five different drugs being developed as a cardiovascular panacea for anyone over the age of 55). The Department of Health estimates that statins prevent about 10,000 early deaths every year, but a small and vocal group of sceptics believes that they are not as effective as claimed and that they cause a number of disabling side-effects.

The statin debate has particular resonance for me. Last week the NHS launched screening “MoTs” for men and women over the age of 40 in the hope of picking up a range of silent problems, such as raised cholesterol levels, and nipping them in the bud through lifestyle advice and medication. Sadly I wouldn't pass such an MoT because I have abnormal cholesterol levels caused by a glitch in my metabolism inherited from my parents - most worryingly high levels of cholesterol are caused by genes, not diet, and, even for those without a genetic defect, most of the cholesterol in their blood is made internally rather than consumed in animal-based foods in your diet.

I am a relatively clean-living, active, slim 46-year-old with normal blood pressure so there is not much that I can do to ameliorate my increased risk other than turn to pills - something that I have been recommending to many of my patients for years. So six months ago I decided to give statins a try and, while fully aware that one swallow doesn't make a summer, so far so good.

There has been a string of articles in the press and on the internet suggesting that statins are largely peddled by overzealous doctors on the back of research that is riddled with vested commercial interest (the global market for statins runs into tens of billions of dollars, making them the most lucrative drugs in the world). But, while I encourage healthy cynicism, in recent years I have got off the fence and joined the majority of my colleagues in the pro-statin lobby.

My own experience of prescribing the drugs is that they are generally well tolerated. There are a number of recognised problems but, after trying out two of the most commonly used statins - atorvastatin and simvastatin - I can't say I have noticed any difference in how I feel. But there has been a dramatic improvement in my cholesterol profile.

Statins work by blocking the action of an enzyme in the liver that plays a key role in the internal manufacture of cholesterol. Taking a statin should lower cholesterol levels by about 20 to 30 per cent - three times the sort of drop that could be expected from switching to the healthiest of diets, and one that is likely to reduce the risk of heart attack and stroke by about a third.

This is a significant protective effect if you are a 55-year-old smoker recovering from your first heart attack (you are very likely to have another, and soon) but of negligible benefit if you are a clean-living 25-year-old marathon runner. Or, to put it another way, a third of a lot is worth having but a third of nothing is not - which is why doctors use risk calculators, rather than cholesterol levels per se, to determine who should be offered a statin (see box).

Although most of the protective effects of statins are attributed to a reduction in cholesterol, and to a slowing of the age-related furring of arteries that eventually leads to most strokes and heart attacks, that is not the whole story. They seem to work in other ways, too - probably by reducing inflammation of the lining of the arteries and stabilising deposits on the wall of the arteries so that they are less likely to tear or break off (the classic precipitating event for most heart attacks). And the benefits do not appear to stop there. Recent research suggests that people on statins are less likely to develop a range of other problems, including aggressive cancers of the prostate, Alzheimer's disease and dangerous blood clots (deep vein thrombosis or DVT).

I don't like having to take any type of medicine, but given the distinct improvement in my cholesterol profile and the lack of any noticeable side-effects, continuing on my statin would seem a no-brainer. What I do not know, of course, is whether hidden long-term effects will emerge once large numbers of patients have been taking the drugs for decades. But, as Winston Churchill was famous for pointing out, most of us spend our lives worrying about things that never happen.

Death, on the other hand, is a certainty - and in my case it is more likely to come from a stroke or heart attack than anything else. And while I cannot prevent the inevitable, statins may help me to delay it.

What are the risks?

Statins are generally well tolerated but can cause side-effects, and there is concern about long-term effects on the brain. Recent research has suggested their use may increase the risk of Parkinson's disease.

Common complaints include flatulence and an upset stomach, sleep disturbance and aching muscles. The latter should be reported to your GP because it can be a sign of potentially fatal reaction (rhabdomyolysis) thought to occur in fewer than one in 50,000 people taking the more popular types.

Long-term use can lead to inflammation of the liver. Some patients, particularly elderly people, complain of mental fogging and poor memory.

Statins deplete the body of the coenzyme Q10, and some doctors believe that Q10 supplements can reduce the likelihood of unwanted side-effects such as muscle pain.

There are no recommendations on dose, but 30mg-60mg daily would be a sensible minimum.

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