In the numerous reviews written by upholders of the diet-heart idea it is often said that this idea is based on ”strong, scientific data”, the evidence is ”overwhelming” or ”extremely powerful” and ”controversy is unjustified”. If you have read the previous sections you will understand that nothing could be more advanced from the truth. To use such vocabulary it has been necessary to exaggerate trivial, apparently supportive findings, to belittle or ignore the wealth of controversial and disproving evidence and to quote unsupportive results as if they were supportive.
How a ”fact” is created by misquoting unsupportive findings and exaggerating trivial findings is examplified in section 1, the story about the so-called ”good” and ”bad” cholesterol.
Observations that are totally devastating for the diet-heart idea are mostly ignored. A good example is the fact that there is no association between the level of blood cholesterol and the degree of atherosclerosis (section 2).
Another one. Before the statin-era overviews of all cholesterol-lowering trials have shown that mortality cannot be improved by lowering cholesterol. But diet-heart proponents usually mention the trials with a positive outcome only and ignore the trials with a negative outcome. Thus, in 16 trial reports published between 1970 and 1992 a total of 40 citations were to (apparently) supportive or inconclusive trials, but with one exception, not a single citation was to unsupportive trials, although the number of supportive and unsupportive trials were equal.
It is interesting to compare the number of citations of papers published in the same journal because few citiations of a paper may simply reflect that it has been published in a little-known or less reputable journal. In 1984 The Lipid Research Clinic´s coronary primary prevention trial was published in JAMA. In that trial 32 of the patients whose cholesterol was lowered died from a heart attack against 44 of the patients in the untreated control group. The total number of deaths (deaths from all causes) was 68 treated patients against 71 patients in the control group. These figures were not statistically significant by conventional statistics, but in spite of that the result was used as the main argument by the American cholesterol campaign.
In 1985 Dr. Miettinen and colleagues from Helsinki, Finland published another, but smaller cholesterol-lowering trial in the same journal. In that trial four patients whose cholesterol was lowered, died from a heart attack, whereas only one died in the untreated control group, and the total number of deaths was ten in the treatment group against five in the control group.
Thus, both papers dealt with the same subject and were published in the same journal and no one has questioned the honesty of the experimenters or the quality of the studies. Reasonably, they should have been cited almost equally often. That the LRC trial, at least according to its directors, was supportive, and the Miettinen trial was not, is unimportant because the aim of research is to find the truth, whether it is happy or not. Here you can see how often the two papers have been cited by other scientists during the first four years after their publication:
|Miettinen and co-workers||LRC-study|
Data according to Science Citation Index
Needless to say, the paper by Miettinen has been cited mainly by more critical scientists.
Yet another example. A common message from the American Heart Association and The National Heart, Lung, and Blood Institute to doctors is that there exist a close correspondence between degree of cholesterol lowering and mortality. Listen for example to the words from The Cholesterol Facts: ”The results of the Framingham study indicate that a 1% reduction of cholesterol corresponds to a 2% reduction in CHD (coronary heart disease) risk.” This statement was followed by a reference to a paper which reported the 30 years experience from Framingham.
But in that paper you can read the following statement:
|”For each 1 mg/dl drop of cholesterol there was an 11% increase (!) in coronary and total mortality.”|
The above examples are just the tip of the iceberg. In a systematic review I have told about the way the three largest, authoritative reviews have misquoted the literature. here comes the abstract:
“Criticism of the diet-heart idea is often met with the argument that consensus committees have settled the issue unanimously. To see how these committees have explained discordant results, quotations from papers with such findings were sought in three recent authoritative reviews. Only two of twelve groups of controversial papers were quoted correctly, and only in one of the reviews. About half of the papers were ignored. The rest were quoted irrelevantly; or insignificant findings in favour of the hypothesis were inflated; or unsupportive results were quoted as if they were supportive. Only one of six randomized cholesterol-lowering trials with a negative outcome were cited and only in one of the reviews. In contrast, each review cited two, four, and six non-randomized trials with a positive outcome, respectively. It appears as if fundamental parts of the diet-heart idea are based on biased quotation.”