Big Fat Sugar Science Arouses Passions

Nothing in nutrition arouses so much passion right now as concerns about sugar science. The runner up would likely be dietary fat. Put them together – as JAMA Internal Medicine did yesterday – and you have fuel for some really juicy headlines.

William Randolph Hearst would be pleased.

Researchers from the University of California at San Francisco (UCSF) examined sugar industry documents dating back to the 1950s. They found that the industry saw a great opportunity in emerging ideas about pushing Americans toward low fat diets.

A shift to low fat diets would lead to people consuming more carbohydrates and thus more sugar. Sugar Research Foundation President Henry Hass told food technologists in 1954:

This change would mean an increase in the per capita consumption of sugar more than a third, with a tremendous improvement in general health.

What’s not to like about that?

The researchers concluded that the sugar industry sponsored research in the 1960s and 1970s that served to promote fat, not sugar, as the primary dietary hazard for heart disease. Therefore, they said, “Policymaking committees should consider giving less weight to food industry–funded studies.”

In an invited commentary, Marion Nestle agreed.

Unfortunately, the issues that should be at the center of this discussion are missing. Scientific rigor and critical thinking are not really mentioned in either of these papers.

Bias can come from industry. It can also come from academic researchers who are deeply, emotionally invested in an idea. It can come from government agencies invested in policies and ideologies. Even nonprofit foundations have their biases. Simply dismissing research funded by industry is a poor substitute for critical thinking.

Transparency about funding sources and potential conflicts of interest has certainly improved over the past 50 years. The scientific rigor of systematic reviews and meta-analyses has improved vastly, as well. It was not until 1976 that Gene Glass actually defined meta-analysis as a means to systematically analyze a large body of research.

The passions aroused by food and nutrition are ancient. Stirring those passions will do little to reduce the bias and improve the rigor of nutrition science. Trading one bias for another is completely unhelpful. Scientific rigor and critical thinking are the best tools for challenging biased and inadequate analyses.

Differing perspectives based on sound reasoning and research should be encouraged, not silenced.

Click here for the paper from UCSF and here for the commentary by Marion Nestle. Click here for perspective from the New York Times.

Sugar and Cinnamon, photograph © Dorte / flickr

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September 13, 2016