Big Sugar Twists the Science behind the Dietary Guidelines

How did Big Corn Syrup and other corporate sugar titans hijack the scientific process?

In 2016, a Washington-based lobby group published a scientific review that concluded the evidence behind guidelines recommending limits on added dietary sugar was “low quality” and didn’t “meet criteria for trustworthy recommendations.” This was a group funded by multinational food and agrochemical companies, from Coca-Cola to Monsanto to the captains of corn syrup, accused of “hijacking the scientific process in a disingenuous way to sow doubt and jeopardize public health.” But exactly how did they get away with it?

As I discuss in my video How Big Sugar Manipulated the Science for Dietary Guidelines, the lobby group questioned “the scientific basis of guideline recommendations on sugar intake” in its paper titled just that. Using the GRADE approach, they concluded that “the overall quality of evidence to support [such] recommendations was low to very low.” GRADE stands for the Grading of Recommendations Assessment, Development and Evaluation initiative, which was developed to make clinical guidelines more evidence-based, and thank heavens for that. Clinical guidelines, like which drug to give to whom, used to be developed by something like the “Good Old Boys Sat Around the Table” (GOBSAT) method.

Under GRADE, it appears that high-quality evidence is exclusively derived from randomized trials. This is not surprising given that the GRADE process was designed for drugs, and, of course, you want your drugs put to the test. The Premarin story is a prime example. For a decade, organizations recommended that clinicians encourage the use of hormone replacement therapy in postmenopausal women, because women who were taking it appeared to have fewer heart attacks. But when put to the test, randomized controlled trials instead showed the opposite. So, we definitely want drugs put through randomized, double-blind, placebo-controlled trials, where people are randomized to take the drug or unknowingly take a placebo instead, and no one knows who’s in which group until the code is broken at the end and the groups can be compared.

Everyone agrees that randomized controlled trials are extremely valuable in many areas of medical research, such as drug testing. But how can this be done with diet? There’s no such thing as a placebo diet. How can people be randomized to different diets while remaining unaware of which one they’re following? People tend to notice what they put into their own mouths. Also, randomized controlled trials are so expensive they typically last for only weeks or months, but it may take decades for cancers to develop; so, it’s nearly impossible to see if different diets prevent or cause cancer in shorter-term trials like that. To see if smoking causes cancer, large cohorts of smokers and nonsmokers can be followed for decades to see who gets cancer and who doesn’t, but people can’t be randomized to smoke or not smoke for decades. When studying lifestyle interventions, randomized controlled trials are often just not possible, and even when they are, they might not be ethical.

Take crib death, for example, also known as sudden infant death syndrome (SIDS). A pivotal study examining the habits of infants who died discovered that sleeping on their stomachs was a risk factor; so, parents were educated with the message “face up to wake up,” and SIDS rates dropped. What more do we need? Would it even be ethical to randomize thousands of babies to sleep on their backs or fronts and count up the deaths? You can get sufficient evidence to make lifestyle recommendations that save lives without randomized controlled trials.

Critical questions, like “What dietary pattern produces the best health outcomes over a lifetime?”, simply can’t be answered with randomized controlled trials. People can’t be randomized to different lifelong diets and be expected to stick to them. So, we need to compile an amalgamation of evidence from other study designs.

The lack of evidence from randomized controlled trials “has become a common argumentation strategy for criticizing nutrition recommendations.” The tobacco industry made similar claims when trying to discredit evidence on the harms of tobacco. Case in point: the “sound science” campaign carried out by Philip Morris. This is all straight out of the tobacco industry playbook.

Philip Morris worked with public relations firms and lawyers to create a “sound science” program that recruited other industries and issues in order to obscure the tobacco industry’s role. They tried to enshrine “‘good epidemiological practices’ that would make it impossible to conclude that secondhand smoke—and thus other environmental toxins—caused diseases.”

“Public health professionals need to be aware that the ‘sound science’ movement is not an indigenous effort from within the profession to improve the quality of scientific discourse, but reflects sophisticated public relations campaigns controlled by industry executives and lawyers whose aim is to manipulate the standards of scientific proof to serve the corporate interests of their clients”—and not just tobacco clients, but potentially those in the food, plastics, and chemical industries, as well. Philip Morris went beyond just “creating doubt” and “controversy” about the scientific evidence; it tried to change the scientific standards of proof. But randomized controlled trials aren’t the only source of good evidence. As Sir Austin Bradford Hill, the pioneer of the randomized controlled trial, put it: “Any belief that the controlled trial is the only way would mean not that the pendulum had swung too far but that it had come right off its hook.”

Doctor’s Note

This is the second in an eight-part series on how industries impact dietary and health guidelines. If you missed the first blog, see The Corporate Playbook behind Undermining Dietary Guidelines. Stay tuned for more; check the related posts below.

The hormone replacement video I mentioned is How Did Doctors Not Know About the Risks of Hormone Therapy?.

For more on sugar industry hijinks, see Sugar Industry Attempts to Manipulate the Science.

You may also be interested in Big Food Using the Tobacco Industry Playbook.