By Michelle Roberts
BBC News Online health staff
This week, cholesterol-lowering drugs called statins have become available to buy at UK pharmacies.
Statins are now available to buy in pharmacies
Doctors have known for a long time that statins reduce the risk of cardiovascular disease - the biggest cause of death in the UK.
Studies show they can cut the risk of a heart attack and stroke by a third.
Statins are given to patients who are known to be at high risk of heart disease, such as those with inherited high cholesterol or people who have already had a heart attack.
This is called secondary prevention.
Increasingly, doctors are suggesting statins should be given to people with risk factors but no obvious disease, which is called primary prevention. This is to prevent disease occurring in the first place.
But is the threat of cardiovascular disease so great that statins may as well be added to the water supply?
This was the debate held recently by doctors at the annual meeting of Heart UK - a patient and science charity for cholesterol.
Dr John Reckless, chairman of Heart UK and a consultant endocrinologist at Bath University, put forward the case.
"The whole point of the debate is to bring out the fact that we are under-treating and the fact that a lot more people could benefit.
"The whole population should be following diet, lifestyle and weight loss measures. We shouldn't have our high- fat meals and we shouldn't lounge around, we should all be taking exercise and so on.
"Of course we all need that. But on the other hand, rather more people do need statins than are currently getting them.
"So maybe people should be able to have their statin, perhaps if not in their drinking water, with their drinking water.
"The issue is how far we should be encouraging wider use," he said.
Dr Reckless said preventing cardiovascular disease was important across the board - in the elderly and the young, in men and women, and in those with diabetes or high blood pressure or any of the other conditions that might go along with it.
"We've long known that the evidence is really that you should be treating way down to really quite a low risk.
Doctors are advised by the Joint British Societies, which includes Diabetes UK, the British Cardiac Society, Heart UK and the Stroke Association, to treat people whose 10-year risk of cardiovascular disease is 20%.
This risk means two in every 10 such people would have a cardiovascular event over the space of 10 years if they were left untreated.
Dr Reckless said studies in the UK and Scandinavia had shown very clear 30-40% reductions in risk of cardiovascular disease when a person's overall risk was only 6% or 9% over 10 years.
"It is clearly effective and safe to treat with a statin at really quite low levels of risk. That doesn't mean to say we are going to treat everyone but you could do," he said.
But Professor Tom Sanders, a nutritionist at King's College, London, and nutrition director for Heart UK, disagreed.
He said although statins were good for people at very high risk of cardiovascular disease, serious side effects made statins unsuitable to be used routinely in those at lower risk.
"It's about balancing the side effects. A public health intervention must have no significant side effects and statins do have significant side effects," he said.
"All the trials are really being done on high risk groups - the elderly, people with diabetes or people with heart disease. The benefit is really confined to people at high risk. We have no trials on low risk groups of exposure.
"At the age of 40, your risk of having a heart attack is below one in 1,000, so any reduction is really quite miniscule in terms of benefit.
"The analogy I use is alcohol. Alcohol saves lives from heart disease at older ages but it's very clear that in people of a younger age who are not at risk it causes more harm than it does good."
Professor Sanders said: "There are serious side effects with statins. One is myositis, in particular rhabdomyolysis - a muscle-wasting disease. It's a very nasty side effect. It can kill you. It occurs in about 0.5 to one in 1,000 people treated and that's with screening. Without screening the incidence might be higher.
"You would not allow something that gives an effect in one in 1,000 people to be added into food."
He said the other worry was the harm it could cause to unborn children.
"It causes limb defects and for that reason you could not put it in the water supply," he said.
But Dr Reckless said: "You might well have statin-free baby water so that babies and others not at risk don't take their statin."
He said similar arguments had occurred when people suggested aspirin use should be widespread.
"I certainly wouldn't agree with that, but quite a lot of people who ought to take aspirin don't. Statins are actually substantially safer than aspirin.
"If you put the average older patient on aspirin in one year, one person in 262 would have a significant gastrointestinal bleed in that one year. The risk with a statin of getting acute myositis to be sufficiently concerned is one per 100,000. So statins are very much safer."
For deaths, he said: "With aspirin it's one in 2-3,000. The number for statins is about one in a million."
Pill popping culture
But Professor Sanders said giving drugs was not the answer. He said it was important to focus on diet and lifestyle.
He said: "It's really a lifestyle disease. Rates have tumbled in the UK by about 35% over the last 20 years and if you look at why the changes have occurred it's been in those who are better off.
"What that tells us is it's a constellation of factors - housing, smoking, bad diets - in those social groups.
"The other thing is people do not always drink water out of the tap. It would not be universal," he said.
He is concerned blanket treatment of everyone would give out the wrong message.
"Most cardiovascular disease could be managed by lifestyle changes. The implication is that diet doesn't matter. I can take a pill for it and it will all get better. It undermines lifestyle changes.
Labelling people as patients
"Putting drugs in the drinking water is medicalisation of human activity. It's wrong. You convert people into patients," said Professor Sanders.
Dr Reckless said: "People vary very much in their approach to prevention and treatments. Some people don't want a doctor near them and others want to maximise their gain.
"Very clearly, you've got to be careful when you treat someone with their first tablet. That can be for some people psychologically quite damaging because you convert them from a person into a patient. That's not good.
"But on the other hand you have the person who goes away and says my doctor won't treat me and I've got a high cholesterol and then gets worried because no one is treating them. Those are an overlapping group of people.
"Perhaps these days where choice is the buzz word, there should be some choice."