Friday, 16 February 2018

The sugar conspiracy debunked

There's been a lot of 'Big Whatever is the new Big Tobacco' rhetoric recently. It's all part of following the anti-smoking playbook which, oddly enough, involves accusing the food/alcohol/soda/gambling industry of following the tobacco industry playbook. It's all so meta, but it's an effective public relations exercise because ad hominem attacks work (read this fascinating study for proof).

The list of businesses that are accused of using 'tobacco industry tactics' is almost endless. Just in the last week, we have seen the booze industry, the baby food industry, the agrochemical industry, the food industry and Facebook all accused of using these mysterious tactics.

Most of the time, the tactics amount to no more than manufacturing a product and trying to sell it; in the final analysis, that is what the single-issue fanatics really object to. The 'tactics' can also often involve lobbying, or rather counter-lobbying as these companies are usually defending themselves from the unprovoked aggression. It is somehow seen as shocking that businesses affected by radical government action tries to have their say (see this 'scoop' from Ireland, for example).

If tobacco industry tactics have a unique meaning in the public's mind, they probably involve covering up evidence and sowing doubt. Of that, tobacco companies have undoubtedly been guilty in the past and the idea that other industries are selling us products that they know to be dangerous is a powerful narrative in these paranoid times. This is the fear to which Stanton Glantz appealed in 2016 when he switched his attention from smoking to sugar. And the global media fell for it. Here is the New York Times, for example...

The sugar industry paid scientists in the 1960s to play down the link between sugar and heart disease and promote saturated fat as the culprit instead, newly released historical documents show.

The internal sugar industry documents, recently discovered by a researcher at the University of California, San Francisco, and published Monday in JAMA Internal Medicine, suggest that five decades of research into the role of nutrition and heart disease, including many of today’s dietary recommendations, may have been largely shaped by the sugar industry.

“They were able to derail the discussion about sugar for decades,” said Stanton Glantz, a professor of medicine at U.C.S.F. and an author of the JAMA Internal Medicine paper.

Glantz's claims were entirely based on an obscure evidence review written in the 1960s by three people, one of whom had undisclosed links to the sugar industry. In those days, researchers did not have to list their interests in journals and it was normal for nutritional scientist to work with the food industry (it still is). The review concluded that fat was a bigger risk factor for cardiovascular disease than sugar. This was an orthodox view then and is the orthodox view now. Glantz did not attempt to challenge this conclusion with empirical evidence. In his mind, one of the authors had received money from food companies so he must be lying.

If you have encountered the anti-carb/anti-sugar crowd on social media, you won't be surprised to hear that this narrative has gone down well. They have a penchant for conspiracy theories and ad hominems, and Gary Taubes has embraced it in his recent book The Case Against Sugar. Nina Teicholz, who borrows liberally from Taubes, created a version of history in The Big Fat Surprise in which John Yudkin's anti-sugar message was silenced by scientists and businesses who wanted people to consume carbohydrates.

There are all sorts of variations of this theory, but the basic theme is that good honest scientists always knew that sugar was the devil, but they were thwarted by devious proponents of the saturated fat hypothesis who shouted them down with the help of lavish funding from Big Carb.

I don't take sides in the fat versus sugar debate. For what it's worth, I think the claims of both factions are overblown. But the narrative presented by Glantz is historically illiterate nonsense and a new study published in Science takes it apart:

Building on a newly popular narrative holding that the low-fat campaign of the 1980s was not based on solid science, these allegations have suggested that if not for the machinations of the sugar industry and its cadre of sponsored researchers, the history of U.S. dietary policy might have unfolded very differently. In this article, we argue that the historical evidence does not support these claims.

Although we do not defend the sugar industry and cannot address every aspect of this history, we believe recent high-profile claims come from researchers who have overextended the analogy of the tobacco industry playbook and failed to assess historical actors by the norms and standards of their time.

Our analysis illustrates how conspiratorial narratives in science can distort the past in the service of contemporary causes and obscure genuine uncertainty that surrounds aspects of research, impairing efforts to formulate good evidence-informed policies. In the absence of very strong evidence, there is a serious danger in interpreting the inevitable twists and turns of research and policy as the product of malevolent playbooks and historical derailments. Like scientists, historians must focus on the evidence and follow the data where they lead.

The article is not behind a pay wall and I highly recommend it. Here are a few more choice cuts...

As we have shown, by the 1960s the paradigm that dietary fat was a likely risk factor for heart disease prevailed among a coalition of scientists closely linked with NIH and AHA and was based on extensive research. By contrast, the sugar theory was developed by a small number of researchers, was supported by limited evidence, and was not accepted by key authorities. Normal science is a social project in which a community of scientists develops consensus over theory. Heart disease epidemiology, in adopting a multifactorial model, could plausibly have accommodated sugar if the theory had withstood testing. But Yudkin's claims were seen as weak and antagonistic, and his signature finding could not be replicated. Moreover, sugar did not appear to meaningfully affect serum cholesterol—the only then-accepted lipid pathway to coronary disease.

As we have also shown, the sugar industry approached Hegsted only after learning of the results of his dairy industry-backed study suggesting that fat and not sugar was a factor in heart disease. “There was no, ‘We'll get money from them and make the results come out this way,’” recalled Lown, who worked in the department. “It didn't happen that way,” he said.

.. We do not claim the sugar industry had no influence on nutrition work at Harvard, nor on the field in general. But we believe that there is no good reason to conclude that SRF's sponsorship of a literature review meaningfully shaped the course of dietary science and policy. Moreover, we think it is an error to demonize, almost as a reflex, scientists and their research when there is evidence of private funding.

.. Our history also underscores the fallacy of emphasizing the machinations of one commodity sector when multiple food industries were deploying similar techniques of influence in the battle for market share. It is notable that during the low-fat era of the 1980s, when suspicion fell heavily on the meat and dairy industries, it was argued that, “The ‘fat lobby’ has not only influenced our nation's food and nutrition policies, it has determined those policies” [emphasis original]. Nearly 40 years later, at a moment when some have said “butter is back” and sugar is toxic, “Big Sugar” is the behemoth accorded these dramatic powers. Caught in the cross fire of these “diet wars” have been the reputations of historical nutrition scientists, whose statures have risen or fallen based on the extent of their contribution to current theories.

If the personal attacks on the authors of this study have not already begun, I'm sure it's only a matter of time.

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