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How Big Sugar killed a 1968 study that pointed to a heart disease link

[NEW YORK] It's no secret that big industries have long devoted tremendous resources to shaping scientific debates that may threaten profits, from Big Oil countering how fossil fuels cause climate change to Big Tobacco pushing back on how smoking will kill you.

This corporate stratagem, manifesting itself as subsidised scientists or lobbyists masquerading as researchers, can also lead to unexpected results. So when it comes to sugar and whether the sweet stuff does a lot more than rot your teeth, a discarded 50-year-old research project may have come back to haunt Big Sugar.

An investigation published Tuesday in the journal PLOS Biology reveals internal emails obtained from public libraries that illustrate how, almost 50 years ago, the International Sugar Research Foundation (ISRF) terminated funding for its own study-one that, according to the PLOS Biology report, was on the verge of linking sugar with bladder cancer and coronary heart disease.

"The sugar industry has maintained a very sophisticated program of manipulating scientific discussion around their product to steer discussion away from adverse health effects and to make it as easy as possible for them to continue their position that all calories are equal and there's nothing particularly bad about sugar," said Stanton A Glantz of the University of California at San Francisco, one of the PLOS Biology study's authors.

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In a copy of a statement obtained by Bloomberg News, the Sugar Association-the current lobbying arm for the industry-called the new report "a collection of speculations and assumptions about events that happened nearly five decades ago".

According to its own review, the industry group said in the statement, the study in question ended because it was delayed, over-budget and overlapped with organisational restructuring.   

Rats fed sugar produced an enzyme associated with bladder cancer. In 1968, the Sugar Research Foundation, a predecessor to the ISRF, launched "Project 259" to answer questions raised by outside researchers about the role gut bacteria played in how humans digest sugar, compared with how they digest starch. Triglycerides that result from the process, in high enough amounts, are a recognized risk factor for heart disease. At the time, evidence was already suggesting the link.

W F R Pover, at the UK's University of Birmingham, was selected to lead the research with about US$29,000-or US$187,000, in 2016 dollars-in funding.

In September 1969, an internal report at the ISRF noted that rats who were fed sugar had higher levels of a particular enzyme, beta-glucuronidase, in their urine.  This discovery wasn't central to the purpose of the research, but the study published Tuesday noted the red flag it should have represented at the time: By the late 1960s, other scientific publications had found a positive association between higher levels of urinary beta-glucuronidase and bladder cancer.

By August 1970, Mr Pover told the SRF that he had almost answered the study's original question. He told the group that his work so far suggested that gut bacteria were, in fact, impacted differently, depending on whether the rats consumed starch or sugar, and that this would likely explain the higher triglyceride levels in sugar-eaters. But he needed a further three months of funding to reach this conclusion more definitively.

The next month, as the Sugar Research Foundation was becoming the International Sugar Research Foundation, Vice President of Research John Hickson described Project 259's value as "nil", and funding for the study's final 12 weeks was cut off. It was never finished, and no results were ever published.

The study "would have added to the evidence that sugar was influencing heart disease risk".

Four years later, though, an ISRF report interpreted the near-finished project's findings, according to the new study: Rats with conventional microbiomes fed a high-sugar diet had elevated serum triglyceride levels, "suggesting the triglycerides were formed from fatty acids produced in the small intestine by the fermentation of sucrose."

In other words, the ISRF was saying, a high-sugar diet may have impacted the rats microbiomes and raised their triglycerides. 

"(The study) would have added to the evidence that sugar was influencing heart disease risk by increasing triglycerides," said Mr Glantz.

"My sense is that this would have represented a substantial contribution at the time. Sugar was saying, 'Don't worry about the sugar-heart disease connections'; this paper would have said, 'Yes, worry.'"

The sugar industry has resisted efforts to declare a link between sugar consumption and heart disease. On Tuesday, the Sugar Association said in a statement that to "allude to a potential connection between sugar and cancer is irresponsible and misleading." 

But Cristin Kearns, a lead author of the new study, said the findings were "just one more piece of information that would have added to the picture that was forming." The implications of what happened to Project 259 go beyond its particular findings, she said. "The sugar industry probably knows more about the health effects of their products than they're letting on."