HOW TO BEAT... HEART DISEASE

But the answer has become a subject of much debate — with implications for many of us on how we lead our lives and the medication we take.

For years the finger of blame has pointed at cholesterol, a fatty substance produced by the liver.

While some cholesterol is vital (it helps produce hormones and vitamin D, for instance), the consensus has been that too much — or rather, too much of the bad form, known as low density lipoproteins (LDL) — damages the blood vessels. This leads to risk of blood clots, heart attacks and stroke.

This thinking was confirmed in 2004 by the hugely influential Interheart study reported in the Lancet, which showed that 45 per cent of deaths from heart disease were caused by high cholesterol — making it the biggest modifiable cause, along with smoking, and outstripping causes such as high blood pressure and obesity.

The message on cholesterol has been twofold: avoid foods rich in cholesterol-raising saturated fat such as butter, cream, milk and cheese, and if you’re at risk of heart disease, take cholesterol-busting statins.

But is it time this two-track approach was rethought?

CUTTING FAT CAN BE BAD FOR YOU

Cutting cholesterol has been a success, according to Professor Peter Weissberg, medical director of the British Heart Foundation, who says better diet — plus a four-fold drop in tobacco use — helped to halve death rates from heart disease between 1961 and 2011. 

‘In the early Sixties, consumption of foods high in saturated fat such as butter, whole milk and red meat was the norm — but they have largely been replaced by low-fat spreads, vegetable oils, skimmed milk and white meat,’ he says.

Yet today there are gaping holes in this ‘cholesterol hypothesis’ — with a growing number of specialists insisting the traditional heart health message is over-simplistic.

The relationship is not as black and white as we thought, says Dr Rajiv Chowdhury, a cardiovascular epidemiologist and a Gates Scholar at Cambridge University.

He led a major review of 72 studies that suggested saturated fat doesn’t cause heart disease.

‘While earlier studies showed saturated fat does raise bad cholesterol, the bigger picture shows it also increases potentially good cholesterol, which reduces bad fats in blood,’ he says. The findings were controversial, but Dr Chowdhury is one of an increasing number of scientists who believe current heart health advice is misguided, if not harmful.

‘The mantra that saturated fat must be removed to reduce the risk of cardiovascular disease has dominated dietary advice and guidelines for decades and led to a Government obsession with levels of total cholesterol,’ says Dr Aseem Malhotra, a cardiologist and medical adviser to the Academy of Medical Royal Colleges.

‘Yet the scientific evidence shows this advice has increased our cardiovascular risks.’

Saturated fat has various subtypes that vary widely in their health effects, says Dr Chowdhury. ‘Without considering these, it’s got to be harmful to replace all saturated fats with sugar or refined carbohydrates — as food manufacturers have been doing in the interests of heart health.’

LOW CHOLESTEROL MAY BE RISKY

The second line of attack is statins, which have been shown to reduce cholesterol even in healthy people, and prevent heart attacks in those with risk factors.

Though they were originally targeted at people with a 30 per cent risk of a heart attack in the next ten years, guidelines have been changed twice (in 2006 and last year), lowering the threshold.

Now anyone with a 10 per cent risk of developing cardiovascular disease within the next ten years should be offered a statin, says the National Institute for Health and Care Excellence (NICE). It says that if everyone at risk took a statin, 8,000 lives could be saved and 28,000 heart attacks prevented a year.

By last year, up to ten million Britons were taking the drugs. Of these, one and a half million had survived a heart attack; two million had severe chest pain (angina); with the remainder at risk because of high blood pressure, high cholesterol, obesity, smoking or diabetes.

‘To make progress in the battle against heart disease, we must encourage exercise, improve our diets still further, stop smoking and where appropriate offer statins,’ says Professor Mark Baker, director of the Centre for Clinical Practice at NICE.

‘The overwhelming body of evidence supports the use of statins even in people at low risk.’

Yet the evidence is not conclusive. One difficult piece of research to explain, published in the American Heart journal in 2009, showed 75 per cent of patients admitted to hospital with a heart attack had cholesterol levels within the safe range; 50 per cent had optimal levels of cholesterol.

Furthermore, your cholesterol falls naturally with age, particularly in older people with chronic health problems.

And it may be unhealthy to have low levels. A 20-year study published in the Lancet in 2001 showed long-term low cholesterol increases the risk of premature death — ‘and the earlier that patients start to have lower cholesterol, the greater the risk’.

‘Cholesterol is wrongly still being demonised as the killer substance,’ says Dr Malcolm Kendrick, a GP and author of the Cholesterol Con. ‘When I tell people the higher their cholesterol level the longer they will live, they look at me as if my medication is not working. They are misguided.’

So, if cholesterol’s role is over-played, what does cause heart disease?

(dailymail.co.uk)