Butter is back. Saturated fat is good for you. Cholesterol is not the cause of heart disease. Claims along these lines keep finding their way into newspapers and mainstream websites – even though they contradict decades of medical advice. There is a battle going on for our hearts and minds.

According to a small group of dissident scientists, whose work usually first appears in minor medical journals, by far the greatest threat to our hearts and vascular systems comes from sugar, while saturated fat has been wrongly demonised. And because cholesterol levels don’t matter, they argue, we don’t need the statins that millions have been prescribed to lower them. A high-fat diet is the secret to a healthy life, they say. Enjoy your butter and other animal fats. Cheese is great. Meat is back on the menu.

This is more than bad science, according to leading scientists and medical authorities. It will cost lives. “Encouraging people to eat more saturated fat is dangerous and irresponsible,” is a typical verdict, in this case from Prof Louis Levy, the head of nutrition science at Public Health England (PHE). “There is good evidence that a high intake of saturated fat increases your risk of heart disease. We need to think about where the sources of saturated fat are and how we can reduce them. The largest contributions are dairy products, including butter, and meat and meat products.”

The advice from PHE, the World Health Organization, the British Heart Foundation (BHF), Heart UK and other institutions and top academics is consistent. Butter and cheese may be fine in modest amounts in a balanced diet, but the saturated fat that they contain is potentially risky. Too much of it causes the liver to overproduce “bad” LDL cholesterol, which is implicated in heart disease.

Mainstream scientists usually keep their disquiet to themselves. But last week, some broke cover over what they see as one medical journal’s support for advocates of a high-fat diet. More than 170 academics signed a letter accusing the British Journal of Sports Medicine of bias, triggered by an opinion piece that it ran in April 2017 calling for changes to the public messaging on saturated fat and heart disease. Saturated fat “does not clog the arteries”, said the piece, which was not prompted by original research. “Coronary artery disease is a chronic inflammatory disease and it can be reduced effectively by walking 22 minutes a day and eating real food,” wrote the cardiologist Aseem Malhotra and colleagues. The BHF criticised the claims as “misleading and wrong”.

David Nunan, from Oxford University’s centre for evidence-based medicine, and three colleagues wrote a rebuttal that the journal at first did not use and then, more than a year later, put behind a paywall, while the original article was free. Last week’s letter of complaint asked Dr Fiona Godlee, the editor-in-chief of the BMJ, which publishes the British Journal of Sports Medicine, to intervene, saying the journal had run 10 pieces advocating low-carb diets and criticising statins in the past three years and that the reluctance to run the rebuttal showed a bias and lack of transparency. She replied defending the journal’s right to challenge “the status quo in some settings”, but allowed free access to the rebuttal.

Every time a new review or opinion is published in an obscure or unlikely journal – sports medicine is, after all, primarily about helping the fit get even fitter – it is picked up by newspapers that know statin scares sell. Very often in the UK they quote Malhotra, a charming and telegenic young cardiologist in private practice whose website describes him as “one of the most influential and effective campaigning doctors in the world on issues that affect obesity, heart disease and population health”. He is, it says, “not just a cardiologist. This is a man who wants to change the world one meal at a time by not just rocking the system but by rebuilding it.”

Malhotra urges a low-carb, high-fat diet. His book, The Pioppi Diet, has the distinction of being named by the British Dietetic Association as one of the five worst “celeb” diet books in Britain – celebrities who have tried it include MPs Keith Vaz and Andy Burnham. It includes lots of fruit and vegetables, olive oil and fish, but otherwise “hijacks” the Mediterranean diet, says the BDA.

“The authors may well be the only people in the history of the planet who have been to Italy and come back with a diet named after an Italian village that excludes pasta, rice and bread – but includes coconuts – perhaps because they have a low-carb agenda,” says the BDA. “The suggestion that this Italian village should be associated with recipes for cauliflower-base pizza and rice substitute made from grated cauliflower or anything made using coconut oil is ridiculous. It also uses potentially dangerous expressions like ‘clean meat’ and encourages people to starve themselves for 24 hours at a time every week.”

Malhotra was appointed as the first medical director of Action on Sugar, formed in 2014 by Graham MacGregor, a professor of cardiovascular medicine. Two years later, the group agreed to go their separate ways. By that time, Malhotra was expressing strong views about statins, claiming in a BMJ article that was later partially retracted that they caused side-effects in 20% of patients. On BBC radio, he went further. “It was actually probably an underestimate,” he said, and questioned the benefits of the drug for any patient, citing the cholesterol sceptic Michel de Lorgeril.

He was accused by Prof Rory Collins at Oxford University of endangering lives. Collins said scare stories about statins could do as much harm as Andrew Wakefield did when he claimed that vaccines caused autism.

When it comes to statins, there is a huge database of research. Since 1994, the Nuffield department of population health at Oxford University, led by two eminent epidemiologists, Collins and Prof Richard Peto, has been amassing and analysing the data in order to figure out how well they work in preventing heart attacks and strokes.

They have published many papers. In 2016, in a major review in the Lancet, they concluded that lowering cholesterol over five years with a cheap daily statin would prevent 1,000 heart attacks, strokes and coronary artery bypasses among 10,000 people who had already had one. It would also prevent 500 in people who were at increased risk, for instance because of high blood pressure or diabetes.

“Our review shows that the numbers of people who avoid heart attacks and strokes by taking statin therapy are very much larger than the numbers who have side-effects with it,” Collins said at the time. Most side-effects can be reversed by stopping the statin, he pointed out – but heart attacks cause permanent damage. “Consequently,” he said, “there is a serious cost to public health from making misleading claims about high side-effect rates that inappropriately dissuade people from taking statin therapy despite the proven benefits.”

But the cholesterol sceptics and statins critics reject the evidence on the basis that the trial data is from big pharma and that the raw data is not in the public domain. Maryanne Demasi, a journalist in Australia whose TV programmes questioning statins were pulled from the ABC network because of concerns over impartiality, wrote in January – again in the British Journal of Sports Medicine – of a “crisis of confidence” in the public because “the raw data on the efficacy and safety of statins are being kept secret and have not been subjected to scrutiny by other scientists … Doctors and patients are being misled.”

There were cholesterol sceptics before statins existed, doubting the hypothesis that high cholesterol in the blood, particularly in the form of LDL, furs up the arteries, leading in the worst cases to a blood clot that can trigger a heart attack or stroke. Yet, says Dermot Neely, a consultant in clinical biochemistry and metabolic medicine and a founder trustee of the Heart UK charity: “The cholesterol hypothesis is supported by a vast amount of scientific data.” Recently, an expert paper was published by the European Atherosclerosis Society summarising all the evidence, to try to silence the sceptics.

But they won’t be silenced. A website called Thincs – The International Network of Cholesterol Skeptics – links to published and unpublished papers as well as the various books its members have written, including a joint one entitled Fat and Cholesterol Don’t Cause Heart Attacks. And Statins Are Not the Solution.”

The director and author of many dissident papers is Uffe Ravnskov, a Danish doctor living in Sweden who has been an independent researcher, not part of any university, since 1979. His most recent review, with 15 others who are mostly members of Thincs, was published last month in the Expert Review of Clinical Pharmacology – an obscure source for newspaper stories that has been brought to the attention of media in the US and the UK, including the Daily Express, which has run many anti-statins pieces. “There is no evidence that high levels of ‘bad’ cholesterol cause heart disease and the widespread use of statins is ‘of doubtful benefit’, according to a study by 17 [sic] international physicians,” said the newspaper.

That is flat-earthism, says Collins. “The claims that blood LDL cholesterol levels are not causally related to cardiovascular disease (which is really in the same realm as claiming that smoking does not cause cancer) are factually false,” he maintains. He believes there is an argument for refusing to give cholesterol-deniers a platform, just as some will no longer debate with climate change sceptics.

Neely says a lot of people ring the nurses and dieticians staffing the Heart UK helpline after reading such stories or hearing about them from family and friends. “We’re very concerned whenever these messages result in people stopping a statin that they were prescribed after their heart attack. Every time there has been a statin scare story in the papers, there is a wave of people who just stop picking up their prescriptions. And as a result of that, many will probably be readmitted with another heart attack down the line,” he says. Some of those are young people who have high cholesterol from birth because of a mutated gene. One of Neely’s patients is a young man whose grandfather and father died of heart attacks at 50. He is on a statin and will be the first in three generations to escape that fate, says Neely.

Asked how he can be sure of his position when the vast majority of top research scientists disagree, Ravnskov says: “Because I am right. The reason why the so-called experts say that I am mistaken is that the vast majority are paid generously by the drug companies.” Asked to elaborate, since statins are out of patent and therefore no longer make money for the companies that originally put them on the market, he expounds on the corruption, illegal practices and wealth of pharmaceutical companies.

The Oxford researchers, including Collins, have published their funding. The unit has research funds from pharmaceutical companies, but the individuals do not take money from them. Ironically, say the researchers, if people refuse statins because of concerns over side-effects, they may be put on expensive newer drugs to lower their cholesterol – and this will make money for big pharma.

A furore was triggered by the recommendation by the National Institute for Health and Care Excellence in 2014 that millions more people should be offered statins. Anybody who has a 10% chance of a heart attack in the next 10 years – judged on factors including weight, age and blood pressure – should consider taking a statin, it said. Anybody who has already had a heart attack or stroke is strongly advised to take one. Because the patents had expired, the pills had become highly cost-effective.

That means statins are given to healthy people to prevent disease and side-effects have become a major issue. The stories are so widespread that people repeat them as if they are incontrovertible, yet the evidence from trials is that even the much-discussed muscle pain is rare. The sceptics dismiss that evidence. Those trials were funded by big pharma, they say, which had a vested interest in hiding any problems with the drugs.

Some side-effects may be caused by interactions with other drugs people are on, such as antibiotics. But there is also evidence that some people get muscle pain because they expect to after everything they have heard. It is called the nocebo effect.

The dissidents’ arguments are attractively simple. Eat fat, avoid carbs and don’t take the tablets, says Malhotra – who declined to answer questions for this article. We would probably all agree that we should ditch junk food and eat well instead of taking pills. But, realistically, telling people to “eat good food” isn’t going to cut it. The majority of people in the UK and the US are now overweight or obese, with all the heart and vascular problems that brings, and the trend is ever upwards.

One thing is for sure – the dissidents are not going to shut up shop. “My belief about the cholesterol sceptics is that they are a bit like religious fundamentalists,” said Neely. “They are not open to argument. Whatever argument you present, they will find another argument because this basically defines who they are.” He cites a cardiologist in the 1980s, Prof Michael Oliver, who was a sceptic of the cholesterol hypothesis that more LDL increased the risk of heart attacks and strokes. Oliver did a U-turn as more evidence accumulated, saying: “When the facts change, I change my mind.” But, says Neely, “unfortunately the cholesterol sceptics we know currently don’t do that”.