BMJ corrects controversial critique of US dietary guidelines report

downloadThe BMJ has published a correction to a critique of the U.S. dietary guidelines report that has received heavy criticism from nutrition experts.

The author, journalist Nina Teicholz, has also posted a response to the criticism of the article.

The BMJ investigation, released in September, asserted that the guidelines committee used “weak scientific standards” to make its recommendations. It also criticized several aspects of the new expert report for the guidelines, such as “deleting meat from the list of foods recommended as part of its healthy diets.”

Soon after the feature appeared, The Verge — who first reported the news of the correction this week — called it “bogus.” The BMJ quickly issued a “clarification” to the paper, in the “rapid response” section of the paper (the journal’s version of a comment section). It noted that the feature should have specified “lean” meats.

The new, official, correction doesn’t formally put the clarification on the record. Instead, it addresses the research behind the analysis about saturated fats. Here it is in full:

This Feature (BMJ 2015;351:h4962, doi:10.1136/bmj.h4962) by Nina Teicholz stated that when the guidelines advisory committee started its work in 2012 there had been several prominent papers, including a meta-analysis and two major reviews (one systematic), that failed to confirm an association between saturated fats and heart disease. This statement did not aptly reflect the findings of the more authoritative of these reviews, by Hooper et al (Cochrane Database Syst Rev 2012;5:CD002137), which found that saturated fats had an effect on cardiovascular events but failed to confirm an effect on cardiovascular mortality.

In its analysis, The Verge argues the correction doesn’t go nearly far enough:

Every five years, the US government issues a new set of dietary guidelines. These guidelines are highly influential; they affect food labeling, school lunches and even scientific research. But this September, the BMJ published an astounding piece of pro-fat propaganda that attacked the committee who issued the 2015 report using factual inaccuracies revealed by The Verge. Now, the BMJ has issued a correction for the article, but its scope is so limited that Teicholz’s article will likely still serve as ammunition for a meat industry that wants to squash the committee’s advice on lowering the consumption of red meat.

The Verge also highlighted the discrepancy between the latest correction and the previous clarification:

The first thing worth noting here is that the BMJ’s correction did not include the items listed in a “clarification” published by Rebecca Coombes — one of the BMJ‘s editors — one week after the article appeared on the journal’s website. This is an interesting choice, since the existence of the “clarification” heavily implies the BMJ felt Teicholz’s story needed further explanation. But given that the clarification was also full of errors, [even] these so-called clarifications wouldn’t make the story right.

For instance, the BMJ‘s clarification states that Teicholz shouldn’t have faulted the committee for “deleting meat” from the list of recommended foods contained in its report — instead, Teicholz should have written that the committee had “deleted lean meats.” But this, too, is factually incorrect. The committee didn’t delete lean meats at all. The committee’s report also states — in plain English — that “lean meats can be a part of a healthy dietary pattern.”

The original BMJ article received heavy criticism from nutrition experts who spoke to The Verge or posted responses to the feature, such as this lengthy note from the 2015 Dietary Guidelines Advisory Committee, chaired by Barbara Millen.

Teicholz’s response to the criticism of her story addresses some of these criticisms that are not addressed in the correction or the clarification. She contends that the report’s methodology is “not reproducible:”

Firstly, Barbara Millen for the DGAC suggests that I was wrong to claim that the committee failed to use a systematic methodology for searching and selecting evidence. However, my article documents a lack of systematic methodology in several places in their report. For example, two statements in the report’s methodology section (Part C Methodology, page 11-12) indicate an approach that is not reproducible.

Teicholz also addresses a statement from Bonnie Liebman, posted on the CSPI website, which calls The BMJ article an “error-laden attack.” Here, Teicholz concedes one point, which became the subject of the official correction notice:

In her response, the Center for Science in the Public Interest’s Nutrition Director Bonnie Liebman points out that, contrary to my statement that recent meta-analyses “failed to confirm an association between saturated fats and heart disease,” one of these reviews, by Hooper et al, 2012, concluded that “reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14%. That figure was increased to 17% in a 2015 update.”

Liebman was correct to point this out. The full sentence in my article was: “When the committee started its work in 2012, there had been several prominent papers, including a meta-analysis (8) and two major reviews (one systematic) (9) (10) that failed to confirm an association between saturated fats and heart disease.” This statement did not aptly reflect the findings of the more authoritative of these reviews, by Hooper et al, which did find an effect of saturated fats on cardiovascular events but failed to confirm an effect between saturated fats on cardiovascular mortality.” A correction to this statement will be posted.

Rafael Perez-Escamilla, a member of the Dietary Guidelines Advisory Committee, told The Verge that he thinks the feature should be retracted:

Hopefully, the BMJ eventually agrees to retract whole paper. [We] will see…

We’ve emailed The BMJ and will update this post if we hear back.

Update: 2/1/16 7:40 p.m. eastern: We’ve received the following statement from Teicholz:

1. RW cites The Verge saying, “…but its scope is so limited that Teicholz’s article will likely still serve as ammunition for a meat industry that wants to squash the committee’s advice on lowering the consumption of red meat.”

Response: This is a speculative, unsubstantiated allegation about politics and is unrelated to the topic of the accuracy of the BMJ piece.

2. RW cites The Verge saying, “But given that the clarification was also full of errors, [even] these so-called clarifications wouldn’t make the story right.”

Response: This allegation is unverified and unsubstantiated. There is no evidence given for the clarification being “full of errors.”

3. RW cites The Verge saying, “But this, too, is factually incorrect. The committee didn’t delete lean meats at all. The committee’s report also states — in plain English — that “lean meats can be a part of a healthy dietary pattern.”

Response: The quote from The Verge refers to a single footnote of the report that was not included in the online version of the report. By contrast, the top recommendation of the report, bolded, as its primary, overarching theme, is this: The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meats;i and low in sugar-sweetened foods and drinks and refined grains. (Part B, Ch 2, p. 2, lines 43-47).

This is its definition of a “healthy” Dietary Pattern, which is repeated 20+ of times in the text of the report

This is a change from the 2010 Report, which states, as its top dietary recommendation, on page 2, “Shift food intake patterns to a more plant-based diet that emphasizes vegetables, cooked dry beans and peas, fruits, whole grains, nuts, and seeds. In addition, increase the intake of seafood and fat-free and low-fat milk and milk products and consume only moderate amounts of lean meats, poultry, and eggs.”

Thus, I think it is fair and accurate to say that although lean meat was downplayed in 2010, it was altogether deleted in 2015. The fact that this 2015 shift is contradicted in a single footnote needs clarification and is a question for the expert committee to answer.

5. RW twice quotes the substance of the BMJ correction.

Response: Regarding the correction, the article was corrected to show that in fact, I understated the strength of the evidence that existed in 2012, when the committee was beginning its work. I did not to make a judgement about saturated fats myself but instead argued that there was enough uncertainty about saturated fat at the time to merit the committee’s requesting a formal review of the topic by the Nutrition Evidence Library (NEL), which is the standard procedure. Yet the committee did not make this request; instead, it did its own review, outside the NEL system.

Regarding RW’s choice to cite the correction twice: This seems redundant and gives the false impression that these are two separate corrections when in fact they are the same.

6. Moreover, I question why Retraction Watch cited, at the top of the piece, that The Verge “called it [the BMJ article] “bogus.”This is an unsubstantiated allegation that is contrary to Retraction Watch’s policy for its comment section: “We will not tolerate these sorts of attacks, allegations, and unverified facts.”

7. In general, Retraction Watch’s exclusive reliance on The Verge for coverage of this important topic is a questionable choice, because of all the media coverage and various opinions expressed about the BMJ piece, the pieces by The Verge were by far the most highly critical. The reporter who wrote those pieces had no background in covering nutrition and had close access to the Dietary Guidelines committee as well as the USDA. Her coverage took the committee’s view entirely and did not attempt balance. By contrast, there was a great deal of coverage of the BMJ piece that was more balanced, by experienced reporters, in mainstream outlets, including the New Yorker, Time, Newsweek, and Yahoo Health.

To provide balance to coverage by the Verge, I would offer the quote, in Cardiobrief, by Arne Astrup, a leading international nutrition expert: “the [dietary guidelines] committee seems to be completely dissociated from the top level scientific community, and unaware of the most updated evidence.”

RW cites The Verge saying “the BMJ published an astounding piece of pro-fat propaganda.
Response: The BMJ piece contains no argument in favor of a higher-fat diet. Regarding fat, it says that the Dietary Guidelines have historically recommended a low-fat diet, which is accurate. Regarding saturated fat, specifically, it makes several arguments about whether the expert committee properly reviewed the last five years of evidence. It is undisputed that the expert committee did not follow standard USDA procedure and consult the Nutrition Evidence Library (NEL) for its review of this evidence. Neither of these points represent an argument for a particular diet of any kind. This statement by The Verge is inaccurate.

Hat tip: The Verge

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