Everyone knows about cholesterol. Everyone “knows” that it is the cause of heart attacks - because that is what they have been told. Everyone knows that cholesterol comes from fatty food. Everyone knows that fat and cholesterol containing foods must be avoided, the ones that taste so good - why is it that the television cookery programmes are all about cream, eggs and butter?
Everyone knows that we should have our blood cholesterol levels measured, and we expect that if it is “high” then we should take statin tablets to lower it. What we do not know is that “high” means total cholesterol greater than 5.2 mmol/L (200mg/100ml), and that this includes about 85% of the adult population.
25% of the over 70s in the West Midlands of the UK take statins and 10% of those below the age of 50. It is also suggested “Statins for all by the age of 50” This is all based on the cholesterol-heart story, that cholesterol in the blood causes the arteries to become “furred-up”, thus becoming blocked and precipitating heat attacks, a serious and incorrect oversimplification.
In recent years we have been in the era of “routine” cholesterol measurements, performed on people who are under the impression that they are normal but who turn out to have a condition called “high cholesterol” (hypercholesterolaemia is the medical term). They are given long-term statin medication and this is the basis of primary prevention of deaths from coronary heart disease.
Change in the USA
But things have suddenly changed, surprisingly in the USA where cholesterol sceptics have not been very obvious and where the diet-cholesterol-heart hypothesis has been most strong.
The new US “Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults” moves away from blood cholesterol concentrations as the basis for prevention! This is a dramatic change and a departure from the first guideline published in 1988, which introduced the 200mg/100ml (5.2mmol/L) threshold, now refined as LDL-cholesterol greater than 190mg/100ml (5mmol/L).
It was obvious from the early clinical trials that the benefit of statins was small but definite. One out of every hundred high risk men treated for five years with a statin each day would have his life prolonged for an uncertain time. But several trials have shown that benefit from statins is not related to either the initial blood level of cholesterol or the degree by which cholesterol is lowered.
The point is that the benefit of statins appears to be independent of the cholesterol-lowering property, probably an anti-inflammatory action. Statin effect extends well beyond reducing risk of death from heart attack (myocardial infarction, MI), with some anti-cancer properties.
These clear points have been avoided in the past years, effectively suppressed by the evangelists of the diet-cholesterol-heart hypothesis, many of whom had considerable vested interests. It looks as though the gravy train is slowing down.
The American College of Cardiology and the American Heart Association are behind this move away from cholesterol, suggesting that prevention of coronary deaths should now be targeted at those at particularly high risk and not at blood levels of cholesterol.
This is a courageous move away from the flawed dogma of the past half-century. It effectively means the beginning of the end of the cholesterol-heart hypothesis. The diet component had been quietly dropped a few years ago: diet is not the cause of heart disease.
And now it is starting to be acknowledged, neither is cholesterol. It is time for medical science to consider what might be the real cause of the epidemic of coronary heart disease.
Cholesterol is involved in the development of coronary heart disease but it is nothing to do with cholesterol in the blood. Cholesterol (as LDL) is part of the tissue inflammatory defensive process and it is in this way that it builds up in the walls of the arteries, probably a response to infection.
Change in the UK ?
How long this change in coronary prevention away from blood cholesterol will take to cross the Atlantic to the UK and Europe remains to be seen.
We know that at the present time the death rate from coronary heart disease has dropped dramatically, the epidemic being almost over about 90 years since it started. The reduction of deaths in the UK has been so great that it will be difficult to identify high risk individuals in the future. The prevention of one coronary death by statins has become very expensive.
It is however a great sense of relief to read of the US change and the dropping of cholesterol screening of the general population. Hopefully things will change soon on the UK, but there will be considerable resistance from the pharmaceutical industry, and those individuals and departments who benefit.
The wind of change approaches.