The study, which involved about 10,000 patients at risk of heart and artery disease, highlighted a "nocebo effect" - the opposite of the placebo effect. In the open-label follow-up study, in which about two-thirds of the patients were taking atorvastatin, there was a small but statistically significant larger percentage of patients in the atorvastatin group who reported muscle-related symptoms: 1.26% per year versus 1.00% per year (hazard ratio 1.41, 95% CI CI 1.10-1.79, P=0.006).
The study echoes findings from other studies, including research published three years ago, which have also suggested the side-effects of statins are minimal, despite up to a fifth of patients reporting side-effects, chiefly muscle pain and weakness.
It is the opposite to the well-known placebo effect, the beneficial response experienced by some trial patients to "dummy" drugs containing no active ingredients. "Vigilance in evaluating drug effects, especially in popular drugs, must continue - but this study shows just how hard it can be to disentangle adverse effects from perceptions of adverse effects".
"This is not a case of people making up symptoms or that the symptoms are 'all in their heads.' Patients can experience very real pain as a result of the nocebo effect and the expectation that drugs will cause harm".
Study leader Professor Peter Sever said: "Widespread claims of high rates of statin intolerance prevent too many people from taking a potentially life-saving medication".
"The uniqueness about the study was that these were the same patients who were followed throughout, they were seen by the same doctors, the same teams, the same way of recording the side-effects", said Sever.
These side effects-including memory loss, erectile dysfunction, nausea and muscle pain-are the main reason many people stop taking the drug, or refuse to go on in the first place.
London cardiologist Dr Aseem Malhotra, who has argued against mass prescribing of statins, last night insisted the drugs had only "marginal" benefits for those with established heart disease, and did not save lives for lower risk patients.
Scientists claimed that millions of patients might get better by themselves if they understood this truth about the drugs. There was no significant difference in rates of erectile dysfunction or cognitive impairment between the two groups.
But subsequently when patients knew they were on statins, reports of muscle-related side effects were 41 per cent more common. There are patients refusing to take statins, Global Positioning System not prescribing them, and patients on statins who are stopping taking them. Observational studies and anecdotal reports indicate that adverse events in people taking statins are common. The researchers said the regulator did not make a "profound value judgement" based on available evidence, and should never have taken such action.
"We would hope that the MHRA will withdraw that request that these side effects should be listed", he said.
He added: "Th ese warnings should not be on the label". Such data have shown the incidence of side effects to be at similar levels whether patients are taking a statin or a placebo.
"It would make life much more simple".
An investigation into statins has demonstrated aching muscles and other reported symptoms could not be blamed on the drugs. These included myopathy, which results in muscle weakness, and the very rare but serious muscle-wasting condition rhabdomyolysis.
He said the only possible explanation was that the pain was not caused by the drug but was due to a "nocebo effect".
Known side effects include an increased diabetes risk, the study said.
"Medicine safety and effectiveness is of paramount importance and is under constant review at a Europe-wide level".