Q&A: The debate over statins
What are statins?
Statins are medicines which lower the level of cholesterol in the blood.
Cholesterol is a fatty substance made from the food we eat. It is essential for the body to work well, but too much 'bad cholesterol' (called low-density lipoprotein) is unhealthy.
High levels of 'bad cholesterol' can increase the risk of having a heart attack or a stroke and of developing cardiovascular disease.
Who takes them?
Between six and seven million people in the UK take statins every day.
They are prescribed by doctors to help protect healthy but high-risk people from heart disease and to prevent heart attacks and strokes in people who have already had problems.
There are different types of statins, but they all work in the same way.
What do they cost the NHS?
The precise figure is not known, but some estimates put the cost to the NHS at around £450m a year.
What is the debate over statins about?
NICE, the National Institute for Health and Clinical Excellence, says that statins should be taken by people who have a 20% or greater risk of developing cardiovascular disease within 10 years.
But a recent in-depth study from the University of Oxford concluded that even low-risk, healthy people would benefit from statins.
The researchers say treating this group, whatever their level of cholesterol, would save lives.
They have called on NICE to look at the evidence for giving statins to more people.
But not all experts agree.
Another study from 2011, by the London School of Hygiene and Tropical Medicine, found there was no evidence to justify people at low risk of developing heart disease taking statins.
Previous studies have also highlighted the side effects of statins for a small number of patients.
What are the arguments for prescribing statins to more people?
Research shows that taking a statin will definitely reduce your risk of having a heart attack, if you are have already had one.
The Oxford study calculated that if people with a 10% risk of cardiovascular disease were prescribed statins, then many more people would take the drugs.
This, it suggests, could save thousands more lives and prevent many more heart attacks and strokes.
In the long run, that could save the NHS money.
And what are the arguments against?
Statins, like all medicines, have potential side effects.
The drugs have been linked to muscle problems and liver and kidney problems, but only in a very small number of cases. In general, they are extremely safe.
There is also concern over whether it is a good thing for society for healthy patients to be taking drugs long-term.
Some experts have suggested prescribing statins to everyone over the age of 50, but others think this sends out the wrong message.
Instead, people should be encouraged to lead healthier lifestyles to reduce their risk of cardiovascular disease they say.
How else can cholesterol be lowered?
You can lower your cholesterol by eating a healthy, balanced diet and doing regular physical exercise.
A healthy diet can stop you gaining weight, thereby reducing your risk of diabetes and high blood pressure.
It can also reduce your risk of some cancers.
The British Heart Foundation says that even if you've already got a heart condition, having a healthy diet can benefit your heart.