Debunking the Debunking of Nutrition Beliefs

Debunking the sacred cows of nutrition makes for fabulous clickbait. But we wonder if it’s helping. Right now, two different examples are generating a lot of heat, but not much enlightenment. One is the never ending debate about the role of carbohydrates and insulin in obesity. The other is a recent review of the evidence for guidance to reduce red meat consumption.

Strong feelings erupt on both of these subjects. Strong conclusions are tougher to find.

Carbs

David Ludwig has published his reply to Kevin Hall’s analysis of Ludwig’s study of energy expenditure on a low-carb diet. In short, Ludwig originally concluded that he had evidence of a higher metabolic rate for people on a low-carb diet. Hall, Juen Guo, and John Speakman raised issues with the methods used to reach this conclusion. So they re-analyzed the data and concluded that the effect claimed by Ludwig was not significant.

Ludwig found little merit in the analysis by Hall et al. Debate and criticism lie at the heart of science, say Ludwig and his co-authors. But they plea for avoiding distractions due to “inconsequential discrepancies and omissions.”

This controversy has been bubbling for a while now. Clearly, one study is not going to prove or disprove strongly held beliefs about carbohydrates. People are passionate about this subject. However, Ludwig and Hall do seem to have one point of agreement. Replication of results is the key to validating or refuting the belief that restricting carbs makes a big difference in metabolism and ultimately, obesity.

Speakman does a fine job of describing why we need more research to answer this question.  He does it in a 19-part tweet here.

Red Meat

Of course, the other hot example of debunking debunkers is all about the health risks of red meat. Five papers in the Annals of Internal Medicine aroused great passions because they challenged a core belief. Nutrition authorities firmly believe that red meat needs to fade from the American diet. Perhaps not entirely. But we’re eating far more than is good for us, they say.

So five papers suggesting that this fundamental belief stands on shaky ground was just too much for many people to take. A group of them pleaded with the journal to “preemptively retract” these papers. In other words, they wanted to shield the public from what they regarded as misinformation. Heresy must be suppressed.

Science and Conspiracy

Such debunking struggles are commonplace today. We live in an age of misinformation. Fake news and real news mingle online. Truth decays. Myths and conspiracy theories rise. In PLOS One, Alessandro Bessi and colleagues describe how conspiracy theories spread online. They document both the attractiveness of conspiracy theories and also the attraction that others have to debunking conspiracy theories.

It’s an unfortunate symbiosis. Incredible energy goes into looking for flawed conventional wisdom and biases. Sometimes that produces fresh thinking. Other times, it’s nothing but a red herring.

In such debates, we don’t need more passions inflamed. We need more objectivity and curiosity.

For the analysis of science versus conspiracy theories by Bessi et al, click here.

Question, photograph © Wee Sen Goh / flickr

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October 10, 2019