Fat in your diet is really bad for you, leads to heart disease and all kinds of other bad things. Or does it. After decades of physicians and consumers being led to believe otherwise, it turns out that there is little to no credible research linking fat in the diet with heart disease. A meta-review published in the Annals of Internal Medicine and a lengthy story in the Wall Street Journal examine the topic. (Annals Article) (WSJ Article) The Annals meta-review examined a large number of studies and concluded that there was no support for guidelines that encouraged eating polyunsaturated fats and avoiding total saturated fats as a way to limit heart disease. This is contrary to the established wisdom, which turns out not to have been based on good science, as the WSJ article outlines. A physician at the University of Minnesota is the original source of this misguided advice, and on closer examination (it has to be asked why this closer examination didn’t occur a long time ago) his research was very flawed. He used selective countries and data for his research; he designed the study to be likely to get the results he wanted and he ignored obvious issues, including sample size and timing issues. And it is not just that the advice to not eat certain fat-containing foods was wrong, this advice led to greater consumption of carbohydrates, which actually do appear to be very harmful in promoting obesity, and to eating other supposedly more healthful fats, which also turn out to have potential bad effects.
So if you are a physician, particularly a primary care physician, trying to do your best to provide good nutritional advice to your patients, you should be very upset, not just because you had to rely on unsound research this time, but how will you know if you can trust the research next time. How can you rely on evidence-based medicine, if the evidence is potentially so flawed? How can there be performance and value-based reimbursement if there is not certainty in the research base being used to determine what good performance is? And because most physicians do care about their patients and their health, how angry would you be that you were encouraged to give patients advice that might actually have been harmful to them.
If you are a consumer, caveat emptor in regard to the research you read about. Unless it is very clear that there was a solid peer review process covering multiple studies, a peer review process that included independent experts in experimental design and statistics, you have every right to be very leery of any research results you read in the newspaper or anywhere else in the daily media. It is a shameful state of affairs that medical science and science in general do such a pathetic job of self-policing; of peer review. And don’t think this is a problem exclusive to medicine; scientists in a number of disciplines increasingly view themselves as advocates and want to report eye-catching results. These tendencies greatly increase the likelihood of bias, manipulation of data, selective use of statistics and reporting of results and other disgraceful conduct. There is a reason why, for example, there is controversy about the existence or extent of greenhouse gas-caused warming. Scientists need to do much better if they are regain and deserve the trust of the public, or of the medical community.