Cholesterol-busting drugs taken by millions of people in the UK have far fewer side-effects than people think, a large study suggests.

Statins are one of the most commonly prescribed drugs in the UK, with around seven to eight million people taking them to cut their chance of heart attack and stroke.

Research suggests that one in every 50 people who take statins for five years will avoid a serious event, such as a heart attack or stroke, due to the medicine.

Now, a new study published in the European Heart Journal (EHJ) has found that reported side-effects from statins may be over-estimated and over-diagnosed.

Experts said up to half of people stop taking statins, cut the dose or take them irregularly due to issues with muscle pain and other side-effects such as digestive problems, issues with sleep and headaches.

Statin intolerance is often defined as an inability to tolerate statins, leading to people cutting down or stopping taking them.

In the new research, which analysed studies on more than four million people, experts put the true level of statin intolerance at 9% or even lower.

They said the true level of intolerance is most likely to be between 6% and 10%.

Statins are a group of medicines that can help lower the level of low-density lipoprotein (LDL) cholesterol in the blood.

LDL cholesterol is often referred to as “bad cholesterol” and is linked to cardiovascular disease, which can increase the chance of strokes and heart attacks, and death.

In the new study, led by Professor Maciej Banach, of the Medical University of Lodz and the University of Zielona Gora, Poland, on behalf of the Lipid and Blood Pressure Meta-Analysis Collaboration and the International Lipid Expert Panel (ILEP), experts analysed 176 studies with 4,143,517 patients worldwide.

People were typically aged around 60 in the study and 40% were female.

Prof Banach said the findings showed that “statins can be used safely in most patients, which is critically important for reducing their cholesterol levels and preventing heart and blood vessel diseases and death.”

He added: “Our findings mean that we should evaluate patients’ symptoms very carefully, firstly to see whether symptoms are indeed caused by statins, and secondly, to evaluate whether it might be patients’ perceptions that statins are harmful – so-called nocebo or drucebo effect – which could be responsible for more than 50% of all symptoms, rather than the drug itself.

“These results clearly show that patients needn’t be afraid of statin therapy as it is very well tolerated in as much as 93%, which is similar or even better than other cardiology drugs, including ones for reducing blood pressure and clotting or blocking of blood vessels.

“What is more, patients need to know that statins may prolong their life and, in cases where side-effects appear, we have enough knowledge to manage these effectively.

“The most important message to patients as a result of this study is that they should keep on taking statins according to the prescribed dose, and discuss any side-effects with their doctor, rather than discontinuing the medication.”

The researchers found that people who are older, female, of black or Asian background, obese, suffering from diabetes, under-active thyroid glands, or chronic liver or kidney failure are more likely to be statin-intolerant.

People on some drugs such as for high blood pressure and those who drink lots of alcohol also have a higher risk of statin intolerance.

Professor Sir Nilesh Samani, medical director at the British Heart Foundation, said: “Decades of evidence have proven that statins save lives. This latest analysis, showing that the risk of side-effects from statins are less than previously thought, should provide reassurance to those who are recommended this medicine to reduce their risk of a heart attack or stroke.

“Furthermore, other studies have shown that side-effects commonly attributed to statins are often not from the drug itself.

“Having said this, the decision to take a statin to reduce the risk of heart and circulatory disease should always be a joint one between a GP and patient after a discussion about the likely benefit.”