BMJ Dietary Guidelines Report Triggers Response From CSPI
29 Sep 2015 --- The Center for Science in the Public interest (CSPI) has written a response to the BMJ article on the new US dietary guidelines which appeared as a feature in the BMJ last week.
Director Bonnie Liebman wrote; “Today’s “feature” in the BMJ by journalist Nina Teicholz continues her distorted and error-laden campaign against the Dietary Guidelines Advisory Committee report. Earlier this year, she wrote a similar mistake-filled op-ed for the New York Times. Teicholz is author of a book urging the public to eat more red meat, cheese, butter, and eggs.”
But Ms Teicholz has responded back to them, saying; “The fact I’m “just a journalist with no credentials” is a logical criticism, based on the assumption that the advice of experts should be trusted more than the advice of non experts. However, the field of nutrition science has become entrenched in its mistakes, a situation that is now becoming obvious: sixty years of expert advice on dietary cholesterol have been overturned, as has the expert advice on the low-fat diet; sixty years of expert advice on saturated fats has been seriously challenged. The reversals on these lynchpins of dietary advice show that the experts have been wrong. Moreover, the real question is whether my arguments have credibility. Are there any strong challenges to them? In fact, serious scientists in the field have responded only with superficial or personal attacks. There has been no critique by a serious scientist of my book. By contrast, in the top journals where my book has been covered (American Journal of Clinical Nutrition, British Medical Journal), it has received extremely strong reviews.”
CSPI’s Liebman goes on to say; “Teicholz would have us believe that only she, not the dozens of experts who systematically reviewed the evidence for these health authorities, has the smarts to accurately interpret this evidence. In fact, she makes many glaring errors in her BMJ piece. Among them, Teicholz criticizes the DGAC for ignoring “a meta-analysis and two major reviews that failed to confirm an association between saturated fats and heart disease.” In fact, the review to which she refers concluded that “reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14 %.”
Teicholz says; “The primary and secondary outcomes of this analysis were total mortality and cardiovascular mortality, respectively. Neither of these was improved by reductions in saturated fats. The tertiary outcome was cardiovascular events, where the 14% improvement was seen, but “events” is a less reliable outcome measure because the identification of a heart attack is subject to variations in detection and diagnosis as well as bias. Death, which is indisputable, is the more reliable outcome measure. And even taking at face value the conclusion on cardiovascular events, let’s say that reducing saturated fats does lessen risk of a heart attack (but not death), the common finding among these trials was that the subjects consuming more polyunsaturated fats (vegetable oils) died at higher rates of cancer. So perhaps one is spared a heart attack only to get cancer instead? This is why total mortality is ultimately the most important outcome measure (death from any cause), and it was not improved on the saturated-fat restricted diets.”
The CSPI went on; “The meta-analysis and second review, whose senior author has been heavily funded by the dairy industry, had serious flaws”, to which Teicholz answers, “It is unfair to characterize the author as someone who has been heavily funded by the dairy industry. While he has received funding from the dairy industry, he is also the recipient of numerous NIH grants and has been a highly respected leader in nutrition for decades. His papers were disputed mainly by one of the original authors of the diet-heart hypothesis, so naturally, he disputes evidence to the contrary. It’s also fair to say that nearly all papers in the scientific literature are disputed. That is the nature of scientific discourse and should be encouraged. What is notable about the authors’ findings is that they have been confirmed now by several other large meta-analyses and systematic reviews And the author of another of the review papers cited in that same analysis by the DGAC report is on the scientific advisory board of a vegetable oil company. So there appear to be interests on all sides.”
Thirdly, the CSPI say, “Teicholz notes that the Women’s Health Initiative found no drop in heart disease deaths after “nearly 49,000 women followed a diet low in fat and high in fruits, vegetables, and grains for an average of seven years.” Yet the eight-year trial was never designed to lower cardiovascular disease.”
Teicholz says, “True, this trial was formally a cancer trial, but other outcomes were measured, including weight and cardiovascular markers. The study directors themselves deemed these other outcomes worthy enough to publish them. CSPI makes a fair point that perhaps these non-targeted outcome measures should not be cited as evidence; however, if that is true, then the DGAC committee should be consistent about their use of its evidence. They routinely rely on the use of non-targeted outcome measures. For example, the reviews published by those committees all rely heavily upon the DASH studies, which were designed to examine blood pressure reduction only, yet are widely cited for their cardiovascular outcomes.”
Liebman continues; “A meta-analysis of many of the trials on saturated fats and heart disease which Teicholz disregards concluded that replacing saturated fats with polyunsaturated fats led to a 19 % reduction in heart disease. Furthermore, the review she uses to disregard the trials was roundly criticized, in part because some of its authors had strong ties to the egg, dairy, and meat industries,” whereupon the Food and Nutrition board was reorganized by the National Academy of Sciences.
The BMJ author responds; “This is an attempt to discount science by citing the industry ties on only one side of the debate. In fact, the following is also true: at the same time that two board members had been found to have ties to the meat, dairy, and egg industries, two other members of the academy’s board were food company employees. And from the start, the academy had been funded by the Nutrition Foundation, whose members included major food corporations.”
Finally, the CSPI says, “Like other health authorities, the DGAC report advised Americans to “consume dietary patterns that are rich in vegetables, fruit, whole grains, seafood, legumes, and nuts; moderate in low and non-fat dairy products and alcohol (among adults); lower in red and processed meat; and low in sugar sweetened foods and beverages and refined grains.” Nina Teicholz’s latest salvo on behalf of saturated-fat-laden meat and dairy foods is a hodge-podge of fact and fiction and will only confuse a confused public even more.”
Teicholz final reply is; “It’s important to note that CSPI has got the science wrong in the past. The group was a principal force in increasing trans fats in the food supply, due to a campaign it ran in the 1980s, when it recommended that fast-food companies abandon beef tallow for partially hydrogenated soybean oil in their french-fry operations. CSPI asserted that saturated fats should be replaced by “healthy” hydrogenated oils, citing evidence that hydrogenated oils had a relatively benign effect on cholesterol, compared to saturated fats. Hydrogenated oils were therefore “not a bad bargain” when it came to heart disease, the group concluded. Due to CSPI’s persistent and public urgings throughout the 1980s, all the major fast-food chains removed tallow, lard, or palm oil from their french-fry operations and converted them over to partially hydrogenated soybean oil instead.”
