Butter, cheese and even red meat are not as bad for the heart as has been maintained, a cardiologist has said in a leading medical journal, adding that it is time to "bust the myth" of saturated fat.

Aseem Malhotra, interventional cardiology specialist registrar at Croydon University hospital, London, also argues that statins have been over-prescribed because of the government's obsession with lowering cholesterol in an attempt to reduce heart disease – and that the side-effects outweigh the benefits for millions of people who take them every day.

Trans-fats found in many fast foods, bakery goods and margarine are indeed a problem, Malhotra writes in the British Medical Journal. But saturated fats in milk, cheese and meat are another matter.

The insistence that saturated fat must be removed from our diet has paradoxically, he says, increased the risk of cardiovascular disease. "Recent prospective cohort studies have not supported significant association between saturated fat intake and cardiovascular risk," he argues. "Instead, saturated fat has been found to be protective."

He adds that it may depend on what sort of foods the saturated fat comes from. Dairy products contain vitamin D, a lack of which has been linked to increased heart disease, and calcium and phosphorus, which may have blood pressure lowering effects. Eating processed meat has been linked to higher rates of heart disease and diabetes, but not red meat.

Malhotra says people have wrongly embraced low-fat products thinking they are better for their health or will help them lose weight, when many are full of sugar. "Last week I saw one patient in her 40s who had had a heart attack," he told the Guardian. "She said she had gained about 20kg in the last six months. She had been drinking five low-fat drinks a day."

He calculated that each 450ml flavoured milk drink contained about 15 teaspoons of sugar, which meant she had consumed 75 teaspoons of sugar each day.

He tells his patients that butter and cheese – though not processed cheese – are better for them than low-fat spreads and that the odd steak will not hurt. Rather than take statins, he said, people with cardiovascular risks should eat a Mediterranean diet, rich in olive oil, fruit, vegetables, fish and nuts. He pointed to a recent study that showed that adopting a Mediterranean diet after a heart attack is three times more effective in preventing further illness than statins.

"In the UK eight million people take statins regularly, up from five million 10 years ago," he writes. "With 60 million statin prescriptions a year, it is difficult to demonstrate any additional effect of statins on reduced cardiovascular mortality over the effects of the decline in smoking and primary angioplasty [a technique used by doctors to widen the arteries]."

In the original trials carried out by drug firms, only one in 10,000 patients given statins suffered a minor side-effect. But among 150,000 patients in a "real world" study – people who had been routinely given statins by their GP – 20% had side-effects that were so unacceptable to them that they stopped taking the pills, including muscle pains, stomach upsets, sleep and memory disturbance, and erectile dysfunction.

Neither Public Health England nor the British Heart Foundation agreed with Malhotra's argument. Peter Weissberg, medical director at the British Heart Foundation, said: "Studies on the link between diet and disease frequently produce conflicting results because, unlike drug trials, it's difficult to undertake a properly controlled, randomised study. However, people with highest cholesterol levels are at highest risk of a heart attack and it's clear that lowering cholesterol, by whatever means, lowers risk."

"Cholesterol levels can be influenced by many factors including diet, exercise and drugs, in particular statins. There is clear evidence that patients who have had a heart attack, or who are at high risk of having one, can benefit from taking a statin. But this needs to be combined with other essential measures, such as eating a balanced diet, not smoking and taking regular exercise."

Alison Tedstone, director of diet and obesity at Public Health England, said: "PHE recommends that no more than 11% of person's average energy intake should come from saturated fats, as there is evidence to show increased levels of saturated fats can raise blood cholesterol levels, in turn raising the risk of cardiovascular disease.

"The government's advice is based on a wealth of evidence. The BMJ article is based on opinion rather than a complete review of the research.

"Evidence specifically linking sugar to cardiovascular disease is limited; however, on average the population needs to reduce its sugar intake. Eating more calories than we need, irrespective of whether they come from sugar or fat, over time leads to weight gain. Being overweight or obese increases the risk of heart disease, stroke, and type 2 diabetes."

But Malhotra got support from those who think sugar is a leading cause of obesity and heart disease. Robert Lustig, paediatric endocrinologist at the University of San Francisco and author of Fat Chance: The Bitter Truth about Sugar, said: "Food should confer wellness, not illness. Real food does just that, including saturated fat. But when saturated fat got mixed up with the high sugar added to processed food in the second half of the 20th century, it got a bad name. Which is worse, saturated fat or added sugar? The American Heart Association has weighed in – the sugar many times over. Plus added sugar causes all of the diseases associated with metabolic syndrome.

Instead of lowering serum cholesterol with statins, which is dubious at best, how about serving up some real food?"