The sugar industry funded animal research in the 1960s that looked into the effects of sugar consumption on cardiovascular health — and then buried the data when it suggested that sugar could be harmful, according to newly released historical documents.
The internal industry documents were uncovered by researchers at the University of California, San Francisco, and described in a new report in the journal PLOS Biology on Tuesday. The report’s authors say it builds on evidence that the sugar industry has long tried to mislead the public and protect its economic interests by suppressing worrisome research, a tactic used by the tobacco industry.
The documents show that in 1968 a trade group called the Sugar Research Foundation, known today as the Sugar Association, funded a research project on animals to shed light on the connection between sugar and heart health. But when the research pointed to a mechanism by which sugar might promote not only heart disease but also bladder cancer, the industry group ended the study and never published the results.
The sugar industry has long insisted that sugar has no unique role in promoting obesity, diabetes or heart disease, though numerous studies by independent researchers have concluded otherwise. Stanton Glantz, a professor of medicine at U.C.S.F. and an author of the new report, said that even though the newly discovered documents are 50 years old, they are important because they point to a decades-long strategy to downplay the potential health effects of sugar consumption.
“This is continuing to build the case that the sugar industry has a long history of manipulating science,” Dr. Glantz said.
In a statement, the Sugar Association disputed the new report, calling it “a collection of speculations and assumptions about events that happened nearly five decades ago, conducted by a group of researchers and funded by individuals and organizations that are known critics of the sugar industry.” The current research was funded mainly by the National Institutes of Health and the Laura and John Arnold Foundation, a private foundation that has given money to support taxes on sugary beverages.
The statement said that sugar “consumed in moderation is part of a balanced lifestyle,” and it emphasized that the Sugar Association remained “committed to supporting research to further understand the role sugar plays in consumers’ evolving eating habits.”
The documents described in the new report are part of a cache of internal sugar industry communications that Cristin E. Kearns, an assistant professor at the U.C.S.F. School of Dentistry, discovered in recent years at library archives at several universities.
Last year, an article in The New York Times highlighted some of the previous documents that Dr. Kearns had uncovered, which showed that the sugar industry launched a campaign in the 1960s to counter “negative attitudes toward sugar” in part by funding sugar research that could produce favorable results. The campaign was orchestrated by John Hickson, a top executive at the sugar association who later joined the tobacco industry. As part of the sugar industry campaign, Mr. Hickson secretly paid two influential Harvard scientists to publish a major review paper in 1967 that minimized the link between sugar and heart health and shifted blame to saturated fat.
The new report on Tuesday revealed additional internal sugar industry documents from that era. They showed that Mr. Hickson was worried at the time about emerging studies indicating that calories from sugar were more detrimental to heart health than calories from starchy carbohydrates like grains, beans and potatoes. Mr. Hickson suspected this might be because microbes that reside in the gut, known collectively as the microbiota, metabolized sugar and starches differently.
In 1968, the sugar organization started what it called Project 259. The group recruited a researcher at the University of Birmingham in England, W.F.R. Pover, and paid him the equivalent of $187,000 in today’s dollars to conduct a laboratory study on animals. The goal of the experiment was to test whether “germ-free” rats and guinea pigs that lacked gut bacteria would respond differently to sugar and starches than normal animals.
The initial results, described in a 1969 internal industry report as “of particular interest,” raised a concern. The rats fed sucrose, the main component of cane sugar, had produced high levels of an enzyme called beta-glucuronidase, which three other studies published around that time had associated with hardened arteries and bladder cancer.
“This is one of the first demonstrations of a biological difference between sucrose and starch fed rats,” the internal industry report stated.
The documents show that Dr. Pover found something else “highly significant.” The initial phase of the research appeared to confirm that sugar’s adverse effects on cholesterol and triglycerides were a result of it being metabolized and fermented by gut bacteria. Dr. Pover said at the time that he was nearing completion of Project 259 but needed an extension to prove “conclusively” that the effects he was seeing were mediated by the microbiota.
But despite having granted him a previous extension, the sugar association decided to pull the plug on Project 259 and eliminate its funding. In an internal report in 1970, Mr. Hickson updated fellow sugar executives on studies that could “elicit useful and significant information” for the industry, and described the value of Project 259 as “nil.” The industry report suggested that Dr. Pover was disappointed, noting that he “expressed hopes of obtaining continuing support from other sources.”
He never succeeded. The research was never published, and it is not entirely clear why. Both Dr. Pover and Mr. Hickson are no longer alive.
A Sugar Association spokeswoman said that the group reviewed its research archives and determined that Dr. Pover’s study ended because it was delayed, over budget and had overlapped with an organizational restructuring.
“There were plans to continue the study with funding from the British Nutrition Foundation,” the statement said, “but for reasons unbeknown to us, this did not occur.”
But Marion Nestle, a professor of nutrition, food studies and public health at New York University, said the internal industry documents were striking because they provide rare evidence that the food industry suppressed research it did not like, a practice that has been documented among tobacco companies, drug companies and other industries.
“From what this paper says, the sugar industry was not interested in answering open-ended questions about whether sugar might be harmful to rats or, given preliminary suggestions of possible harm, doing further studies to find out one way or the other,” she said. “Instead, it stopped the research when the results looked unfavorable.”
The New York Times