In a paper published in JAMA Internal Medicine in 2016, researchers suggested that in the 1960s, the sugar industry paid scientists to obscure the relationship between sugar and heart disease, derailing the course of nutrition science and policy for years to come. Now, two researchers at Columbia University say that those claims are not backed by the historical evidence, and by promoting the idea of a “sugar conspiracy,” they hinder our understanding of how science is actually done.

In 2016, after reviewing internal industry documents, researchers at the University of California, San Francisco showed that a trade group called the Sugar Research Foundation (SRF) paid Harvard scientists to review what the literature said about the role of fat and sugar on heart disease. The review, published in 1967 in a prestigious journal, downplayed the role of sugar, blaming saturated fats instead. Last year, the same UCSF group published another paper claiming that in the 1960s, the SRF also stopped funding research that began to show that rats on a high-sugar diet had high levels of triglycerides, which increase the risk of heart disease. “They were able to derail the discussion about sugar for decades,” one of the UCSF researchers, Stanton Glantz, told The New York Times.

“it doesn’t capture the whole picture.”

Those conclusions, however, overstate the evidence, according to an article published last week in Science. “We do not claim the sugar industry had no influence on nutrition work at Harvard, nor on the field in general,” the article says. “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.” Plus, several other industry groups — like the meat and dairy industry — were also funding research at the time. “To boil it all down to the sugar industry, in our view, it doesn’t capture the whole picture,” says David Merritt Johns, a PhD candidate in the Department of Sociomedical Sciences at Columbia, and one of the authors of the Science article.

Today, we know that eating lots of added sugars — in sodas, for instance — as well as some types of fats, like trans fats, can increase your risk of heart disease or diabetes. But in the years after World War II, when obesity and heart disease were already starting to plague Americans, the evidence wasn’t clear. By the 1960s, fat had emerged as a plausible culprit, and some researchers were looking into sugar as well. At the time, it was normal for the food industry to fund research, and journals didn’t require researchers to disclose where their money came from, Johns tells The Verge.

Harvard scientist Mark Hegsted was one of the researchers who was paid $6,500 ($49,000 in today’s money) by the sugar industry to review the research on fat, sugar, and disease, according to The New York Times. His results, published in 1967 in the New England Journal of Medicine, blamed saturated fats rather than sugar for heart disease. In 2016, the UCSF researchers revealed that the review was paid for by the Sugar Research Foundation, which the New England Journal of Medicine hadn’t disclosed. The SRF had also cherry-picked which papers had to be reviewed. “Hegsted and his colleagues applied a double standard to their critique of the epidemiologic, experimental, and mechanistic evidence linking sugar to heart disease,” says Cristin Kearns, assistant professor at the UCSF School of Dentistry, in an email to The Verge.

“Hegsted and his colleagues applied a double standard to their critique.”

That said, Johns says that Hegsted had “a reputation as a very scrupulous guy,” and he had done other studies that had results that didn’t align with his funders, such as the North American Meat Institute. “Under the Reagan administration, Hegsted would be fired from his job developing the first US Dietary Guidelines after his low-fat approach provoked the ire of the beef industry,” the Science article says. And in 1977, the Dietary Goals for the United States, which was edited mainly by Hegsted, also recommended lowering sugar intake by 40 percent because of its link with tooth decay and possibly diabetes.

The focus on dietary fats did go on to influence guidelines for years to come. In the 1980s and ‘90s, Americans were encouraged to eat fewer fatty foods. As a result, all types of fats — good and bad — were reduced, while sugar intake went up, says Walter Willett, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. Some believe that was the spark to the obesity epidemic plaguing the US right now, The New York Times says. More than 30 percent of US adults are obese; and obesity costs the US an estimated $147 billion a year, according to the CDC. “That push was, unfortunately, more the result of well-intentioned people who didn’t pay attention to the data,” Willett tells The Verge. “That wasn’t really driven by the sugar industry primarily.”

Johns agrees: “The twists and turns in science and in policy are not always the product of malevolent forces,” he says. Still, the UCSF researchers disagree with that take. “Our focus is not on the (unobservable) motivations or ethics of specific individuals,” Kearns writes in an email to The Verge. “Our focus is on understanding the impact of the sugar industry’s research program, which spans more than 50 years.”

One thing is clear: the food industry keeps funding research today — with dire consequences. In 2015, The New York Times reported that Coca-Cola had paid scientists to distract the public from the connection between sugary drinks and obesity. In 2016, The Associated Press showed that candy makers funded a study showing that kids who eat candy weigh less than those who don’t.

“In an ideal world, probably nutrition research would be much more heavily funded by the government,” Johns says, “but the government also has a limited amount of money and has to choose priority.”