In 2007, Cristin Kearns was a general manager at Kaiser Permanente, where she ran a large group of dental practices. She was working with medical doctors at Kaiser to figure out ways they could provide better care for patients with diabetes, who are more likely to have gum disease. The work took her to a conference in Seattle focused on the links between the two diseases. As she watched the talks, attended the panel discussions, and read the materials handed out, she was struck by one thing: No one seemed to be talking about sugar. Even a pamphlet intended for diabetic dental patients didn’t suggest cutting back on sugar.

“I had this experience, which I found to be very strange, and I was wondering whether the sugar industry had an influence” on what was included in those patient materials, Kearns said in an interview. So she started digging. “I had a full-time job—research journalism wasn’t part of my job. I just was Googling at night after work.”

Today, as a postdoctoral researcher at the University of California, San Francisco, Kearns is publishing research based on the documents that her casual Googling led to: a trove of confidential documents, correspondence, and other materials that detail the relationship between the sugar industry and medical researchers in the 1960s and ’70s that UCSF has taken to calling the “Sugar Papers.”

Last year, she and her colleagues revealed that the sugar industry worked with the National Institutes of Health during those years to create a federal program to combat tooth decay in children that did not recommend limiting sugar consumption. On Monday, in a paper published in The Journal of the American Medical Association, Kearns details how in the 1960s, the leading sugar industry trade group paid three Harvard researchers nearly $50,000 in today’s dollars to publish a literature review that would link fat and cholesterol—and not sugar—to increased risk of heart disease.

The Sugar Research Foundation, which is now called the Sugar Association, “set the review’s objective, contributed articles for inclusion, and received drafts,” according to ...