Some time ago, one of my regular readers wrote to me and said she felt there were a lot of confused messages regarding which fats are good, which are bad and which products to use.
I had planned to write about cholesterol, so I hope I can combine the two subjects. However, this is a complex subject, so there will be a follow up next week. This week we have the history of how we arrived at the theory that cholesterol is bad.
After World War II, people used heavy fats to cook with, the frying pan had lard in it and in the UK oil was not used because it was too expensive and difficult to get hold of. This habit varied depending on which country you were in.
However, generally there was a high usage of fats, such as butter and the old style margarine such as Stork. Both lard and Stork were incorporated into baking and used regularly. By the 1950s, coronary heart disease (CHD) had become the major killer in the West.
The question arose, what had caused this sudden increase in CHD deaths? The answer leads back to the deprivations of World War II. The subject of nutrition and proper diet was not considered when life began returning to normal after the war and it was just wonderful to get anything to eat that was filling.
The general consensus was that this increase in heart disease must be linked to all the food everyone had been eating after the war. Some scientists suggested the rise in CHD was related to the rise of hydrogenated vegetable oils found in foods such as margarine and biscuits . They felt that if we returned to the old-style foods, there would be education in heart disease.
There was another theory which demonstrated that cholesterol fed to rabbits caused atherosclerosis (Am. J. Physiol.,1954). David Kritchevsky, a researcher at Wistar Institute in Philadelphia, US, told the American Oil Chemists’ Society that polyunsaturated fats – found in vegetable and corn oils, soybeans, safflower and sunflower seeds – could reduce cholesterol.
This theory gained ground, and in two years the ‘lipid hypothesis’ had gained momentum. As a result, in 1956, the American Heart Association launched the ‘Prudent Diet’. This advised corn oil, margarine, chicken and cold cereal should replace butter, lard, beef and eggs.
Following on from this, in 1958, the Mediterranean diet was born. Another researcher, Ancel Keys of the University of Minnesota, launched the ‘Seven Countries Study’, a hugely influential study which led to the birth of the Mediterranean diet concept.
In fact, later analysis of the study revealed that Keys had been highly selective in his data and had chosen the results which supported the high fat hypothesis. It was called the Seven Countries Study, but Keys had actually studied 22 countries and ignored the results of 15 of them.
Apparently, if he had used all the data, the diet-cholesterol link would have disappeared. This is evidenced in detail in The Cholesterol Myths by Danish researcher Uffe Ravnskov. This book was so reviled by the medical establishment that a copy was burned during a live television show in Finland.
This is where my reader’s comment that there is confusion becomes clear. The confusion has been ongoing for years.
There is a host of other research relating to CHD that has been suppressed or changed to suit requirements. A quote from Quart. J. Med, 2003 states, “not only doesn’t a high-fat diet raise our levels of cholesterol, the next part of the theory – that cholesterol causes CHD and heart attacks – also doesn’t add up”.
Ravnskov has identified around 15 studies that clearly demonstrate that cholesterol plays no role in the development of CHD’.
The statistics don’t add up either. The percentage of men in the UK who have “dangerous” levels of cholesterol has fallen from 75 per cent in 1994 to 58 per cent in 2008. The largest drop is in the 75+ age range, with only 39 per cent of the male population found to have dangerously high levels compared with 79 per cent in 1994.
Despite all this, the incidences of CHD have remained fixed over the 10 years leading up to 2008. In fact, the level of CHD has risen slightly in the over-75 age group, which is the group who has seen the most dramatic reduction in the extent of high cholesterol, from 24 per cent in 1988 to around 30 per cent in 2008 (Coronary Heart Disease Statistics 2010, British Hearth Foundation).
More confusion, but the fact remains that heart disease is still a major killer in the West. So the question is ‘if fatty foods are not the cause of our clogged arteries what is?’
Inflammation is recognised as playing a role in CHD, although it is not a cause – it is the body’s immune system response to stress and infection. We will look more at the role of stress and LDLs and how statins fit into this picture in the second part.
kathryn@maltanet.net