by Uffe Ravnskov MD (www.ravnskov.nu/cholesterol.htm)
Saturated fat is the type of fat that dominates in animal food such as eggs, cream, meat and cheese and is also abundant in palm and coconut oil. Today many of our scientists consider too much saturated fat just as dangerous to our arteries as are greasy food leftovers for the drains of our kitchen sink. Since only 10,000 years ago, as hunter-gatherers, our paleolithic diet cotained abundant saturated fat, other scientists question this.
For several years sceptical scientists including myself have asked the experts on the Swedish National Food Administration after the scientific studies that allow them to warn against saturated fat. Their usual answer have been that “there are thousands of such studies”, or they refer to the WHO guidelines,1 said to have been written by the world’s greatest experts.
The main argument in that document is that saturated fat raises cholesterol, but we now know that high cholesterol is not a disease. What we want to know is if we shorten our life or if we run a greater risk of getting a heart attack or a stroke by eating too much saturated fat.
Recently the Swedish Food Administration published a list of 72 studies that they claimed were in support of their warnings. Together with eleven colleagues I scrutinized the list and found was that only two of them were in support.
Eleven studies did not concern saturated fat at all.
Sixteen studies were about saturated fat, but were not in support.
Three reviews had ignored all contradictory studies.
Eleven studies gave partially or doubtful support.
Eight studies concerned reviews of experiments where the treatment included not only a “healthy” diet, but also weight reduction, smoking cessation and physical exercise. So how did they know whether the small effect was due to less saturated fat or to something else? Furthermore, all of them had excluded trials with a negative outcome.
Twenty-one studies were about surrogate outcomes. In most of the reports the authors claimed that saturated fat raises cholesterol. But again, high cholesterol is not a disease.
Twelve studies were listed because they had shown that people on a diet with much saturated fat and little carbohydrates reacted more slowly on insulin than normally, From that observation the authors claimed that saturated fat causes diabetes, but they had jumped to the wrong conclusion.
Saturated fat does not produce diabetes; on the contrary. More than a dozen experiments have shown that the best cure for people with type 2 diabetes is a diet with much saturated fat and very little carbohydrates. In a few days their blood sugar normalizes and many of the patients are able to stop their medication.2 Another contradiction to saturated fat causing diabetes is that for many years the consumption of saturated fat has decreased in most countries and during the same period we have seen a steady rise in type 2 diabetes.
The Food Administration also published another list with eight studies which they said contradicted their warnings. However, that list was incomplete, to put it mildly. For instance, why didn’t they include the many studies of the Masai people who have the lowest cholesterol ever measured in healthy people although more than sixty percent of the calories in their food come from saturated fat?3 And why didn´t they mention that no study has ever found an association between people´s cholesterol and their intake of saturated fat? 4
I reviewed also the more than thirty studies having shown that patients with heart disease or stroke have not eaten more saturated fat than healthy individuals.4 Indeed, seven studies have found that stroke patients had eaten less.5
The strongest proof for causality is experiments on human beings. If saturated fat causes heart disease, a reduction of such fat in the diet should lower the risk, this is pure logic. But up to 1997, nine such trials had been published and when all the results were put together in a so-called meta-analysis, no effect was seen whatsoever. In a few of the trials the experiment resulted in a little fewer deaths in heart disease, but in other studies mortality had increased.4,6
How come that still to-day saturated fat is seen as a menace to health? What is the evidence?
The truth is that there is none. As I shall demonstrate in the following, the warnings against saturated fat are based on manipulated data.
Ask any scientist in this area to list the names of those who have created the diet-heart idea and nine out of ten probably put the name Ancel Keys on the top. Keys had no clinical experience; he was an American professor in physiology. Maybe this explains the many curious conclusions he has drawn from his studies about heart disease
One of his first contributions in this area of science was a paper from 1953 where he stated that heart disease was caused by too much fat in the diet. As an argument he used a diagram showing the association between fat consumption and heart mortality in six countries. It looked very convincing, because all observations were in accord. On top was the figures from the US; at the bottom those from Japan. In the US people ate five times more fat than in Japan, and heart mortality was fifteen times higher. The data from the other countries lay all between forming a beautiful curve starting in the lower left corner and ending in the upper right.7
But Keys’ paper was a fake. At that time information was available from twenty-two countries. This is what two American scientists revealed four years later.8 Their conclusion was clear: “The apparent association is greatly reduced when tested on all countries for which data are available instead of the six countries used by another investigator.” The death rate from coronary heart disease in Finland, for instance, was seven times that of Mexico, although fat consumption in the two nations was almost the same.
But nobody reacted, and his paper is still used by to-day’s experts as an argument for their dietary guidelines.
Also used is another of Keys´ papers, called Seven Countries.9 In that study he followed sixteen population groups in seven different countries and from his observations he concluded that one of the most important factors behind heart disease was too much saturated fat in the diet.
If you eat too much saturated fat, he claimed, your cholesterol goes up. This was what he and other researchers had seen in dietary experiments where they had given healthy people various amounts of fats. When they gave them much saturated fat and little polyunsaturated fat, the fat that dominate in most vegetable oils, their cholesterol went up. And when they did the opposite, cholesterol went down. Their message was swallowed by the rest of the world. Anyone who question this sacred dogma today is considered a quack.
His idea was questioned by Raymond Reiser, an American professor in biochemistry, who pointed to several errors in Keys’ argumentation.10 Instead of giving the test individuals natural saturated fat from animal food in the experiments, many authors had used vegetable oils saturated by hydrogenation, a process that also produces trans fat, and to-day we know that trans fat indeed causes cholesterol to go up. In addition, when cholesterol went up, researchers attributed the effect to high intakes of saturated fat when in fact it could have been due to low intakes of polyunsaturated fat, and vice versa.
What definitely argues against a cholesterol lowering effect from saturated fat is the outcome of modern dietary trials where scientists have used a diet low in carbohydrates with a high content of saturated fat to combat diabetes and/or obesity. By avoiding bread, potatoes, cakes, cookies, candies and soft drinks these scientists have achieved amazing results. In a few days many diabetic patients were able to skip their insulin and the effect on body weight was much better than those who followed the dietary guidelines.11 And here comes the surprising finding. Even if the diet covered 20-50 percent of calories with saturated fat, nothing happened with the patients’ cholesterol, a finding that has been confirmed in many trials.12
And there is more. Already in the eighties American researcher Ronald Krauss found that the most useful risk marker, the best predictor of heart disease among the blood lipids, wasn’t the total amount of cholesterol in the blood, neither the bad guy LDL cholesterol, but a special type of LDL particles, the small, dense ones. The most surprising finding was that if somebody ate much saturated fat the number of these small, dense LDL particles decreased.13
Krauss is not only a brilliant researcher, he is also a member of the committee who write the dietary guidelines for the American people. When I met him in Chicago a few years ago I asked him why they with his results in hand still warned against saturated fat.
“Oh, you see”, he answered, “the members of the committee do not always agree, and when we don’t agree, we decide what to recommend by voting”.
I wonder if the committee voted also when they discussed the study by Indian researcher Malhotra. For six years he registered how many who died from a heart attack among the more than one million employees of the Indian railways. According to Malhotra’s report employees who lived in Madras had the highest mortality. It was six to seven times higher than in Punjab, the district with the lowest mortality, and they died at a much younger age. But people in Punjab ate almost seventeen times more fat than people from Madras and most of it was animal fat. In addition they smoked much more.14
Many of the experts in the committee must have been sceptical to Malhotra’s result: “How is that possible? How many of you believe in such nonsense? Raise your hands!”
Maybe they hadn’t read Malhotra’s paper? But they did know the Japanese migrant study, because it is used again and again in the official papers as one of their strongest arguments.
At the time of that study Japanese ate little animal fat, their cholesterol was low, and coronary heart disease was rare, as it is still to-day. It is of course tempting to link them together and use it as an argument for avoiding animal fat, in particular with the results from the migrant study in hand.
What the investigators found was that when Japanese people emigrated to the US, their cholesterol went up and they died more often from heart disease, and at that time saturated fat was a major ingredient of the food.
Isn’t this a wonderful demonstration of the importance of avoiding saturated fat?
One of the members of the research team was Dr. Michael Marmot, a British researcher who has taught us much about the influence of stress and social factors on heart disease. Marmot found that it was not the food that raised the Japanese emigrants’ cholesterol, nor the higher cholesterol that increased their risk of heart disease. He could state that with certainty because Japanese emigrants who maintained their cultural traditions kept their low risk of heart attacks, although their cholesterol increased as much as in those who adopted a Western lifestyle. The most striking of Marmot´s findings was that emigrants who stuck with the Japanese traditions but preferred the fat American food ran a smaller risk of heart disease than those who accustomed to the American way of life but ate the lean, Japanese food.
Isn’t this a wonderful demonstration of the unimportance of avoiding saturated fat?15
But let me return to Seven Countries. Apparently very few have read the full 260 pages report, because if you do that meticulously, as I have done, you will soon discover findings that are at odds with Keys´ idea that saturated fat causes heart disease. For instance, although the intake was almost equal in the Finnish population groups from Turku and North Karelia, heart mortality was five times higher in North Karelia than in Turku. And although the intake was equal on the two Greek islands Crete and Corfu, heart mortality was almost seven times higher on Corfu than on Crete.
Saturated fat is the type of fat that dominates in milk, cream and cheese. Therefore, most authorities warn against them and recommend low-fat milk, even for the children. But where is the evidence? Is cream really poisonous?
In a British report the authors had put together data from ten large studies including more than 400,000 men and women who had been followed for several years. What they wanted to know was whether intake of dairy products was deleterious to health. What they found was that the number of heart attacks and strokes were smaller among those who consumed the most dairy products compared with those whose intake was the lowest.16
I assume that you are curious to know how the Swedish Food Administration responded to our criticism. They did respond, but we couldn’t find an answer to our questions about saturated fat. Indeed, we could not even find the term saturated fat in their text. Instead we could read statements such as ”Our dietary guidelines are based on science….they are a synthesis of thousands of studies…they are similar with the international guidelines.”
Have you heard that before?After close to twenty years of meticulous reading of the scientific reports about this issue I haven’t found any valid argument against saturated fat, and I am not alone; other researchers have sought in vain as well.17 Instead, as you know already, there are a large number of contradictory observations. Let me therefore return to the WHO/FAO Expert Consultation1 to see what the world’s best experts have to say about it.
According to that paper “the relationship between dietary fats and CVD (cardiovascular disease), especially coronary heart disease, has been extensively investigated, with strong and consistent associations emerging from a wide body of evidence”. This statement is followed by a reference to a consensus report from the Nutrition Committee of the American Heart Association.18 The only evidence presented in that paper or in other official documents for an unhealthy effect of saturated fat is its effect on cholesterol, and a single study claiming that intake of saturated fat may cause heart disease.19
The first statement that saturated fat causes cholesterol elevation is not true, as you know by now. That intake of saturated fat causes heart disease is not true either, although the authors said so in the summary of the paper: “Our findings suggest that replacing saturated and trans unsaturated fats with unhydrogenated monounsaturated and polyunsaturated fats is more effective in preventing coronary heart disease in women than reducing overall fat intake.”19
Probably you think that the study was a dietary trial, but it was not. It was a study of 80,000 healthy nurses who had been followed for almost twenty years. At the start and every other year the researchers from Harvard asked them in detail about their usual diet. At the end of the study the diet of those who had suffered a heart attack was compared with the diet of those who had remained healthy. The term “replacing” did not mean that they had replaced anything; it was a result of complicated statistical calculations based on the dietary information. The truth is, that on average there were just as many statistically significant heart attacks among those who had the lowest intake of saturated fat as among those with the highest; this fact appears clearly from the tables in their report.
Furthermore, the research group from Harvard has published a number of similar reports during the previous years and none of them found a difference, and as mentioned above, at least twenty other research groups from all over the world haven’t succeeded either.
A relevant argument against such studies is that what the participants tell you about their diet is not necessarily true. Who can remember what they ate yesterday and how much? And can we be confident that they eat similar food and similar amounts of that food next week or next year?
A better way to know how much saturated fat we have eaten is to analyze the amount of various fatty acids present in our fat cells. It has been shown that the number of the short saturated fatty acids reflects the intake of saturated fat during the previous weeks or months.20 In at least nine studies researchers have determined the amount of these fatty acids in the fat cells. In six of them the content was similar in patients with cardiovascular disease and in healthy individual meaning that the patients evidently hadn’t eaten more saturated fat than healthy people. In the rest the patients had fewer short chain fatty acids, meaning that they had eaten less saturated fat than the healthy control subjects.21
Please log in again. The login page will open in a new tab. After logging in you can close it and return to this page.