Shaky Confidence in Nutrition Science

Two researchers from the Harvard Medical School tell us we cannot have confidence in findings the World Health Organization gleaned from nutrition science related to sweeteners. But the problem is not limited to sweeteners. Writing in the New York Times, Anupam Jena and Christopher Worsham say the problem afflicts much of nutrition research:

“This is not a problem reserved for artificial sweeteners alone. The state of nutrition research is poor, and the problems afflict much of the research into dietary and lifestyle claims around things like coffee, wine, dark chocolate, fad diets, the amount you exercise — you name it. This in part explains other recent flip-flopping around whether moderate drinking is “good” for you: A recent review found the research methods used in many past studies on the benefits of drinking alcohol to be flawed.”

Leaning on Toxic Labels for Sweeteners

For example, a recent study in Journal of Toxicology and Environmental Health Part B stirred up a great deal of interest. Its authors spun out a press release to say chemicals found in sucralose are genotoxic. So news outlets jumped on this story. Headlines told us “America’s most popular sweetener damages our DNA.” In case that’s not enough, they added claims it “causes leaky gut.”

A few people stepped back to point out that these were lab studies of a derivative of sucralose. Not the sweetener itself. Not in humans or any other whole animals. But no description of the limitations of this research found its way into this paper. Perhaps that is what made it a good source for clickbait.

It has garnered more than 100,000 views already – in a journal that typically gets only 96,000 views over the course of a whole year. Great clickbait indeed.

Information or Affirmation?

We have a fundamental question to ask ourselves. Do we want information or affirmation from nutrition research? If the goal is information and insight, then research tools for building confidence in nutrition science are available. Jena and Worsham point to Mendelian randomization and natural experiments as two examples of such tools. A short course next week will focus on strengthening causal inference in behavioral obesity research at the Indiana University School of Public Health and we will be participating.

So we have options. Scientists, communicators, and even the public have a role to play in sharpening our skills for discernment and critical thinking. Seek more from nutrition science than affirmation of your beliefs. Stay curious.

Click here for the article by Jena and Worsham.

Confidences, painting by Edward Henry Potthast / WikiArt

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June 20, 2023