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Sugar industry sponsored research to downplay sugar's role in heart disease
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The Sugar Association, previously known as the Sugar Research Foundation, funded research that promoted fat as the leading dietary cause of coronary heart disease, according to a historical analysis published in JAMA Internal Medicine.
The analysis found that the sugar industry sponsored a program aimed at influencing research to challenge the dangers of sucrose consumption and its association with coronary heart disease, Cristin E. Kearns, DDS, MBA, from the University of California, San Francisco, and colleagues wrote.
Researchers reported that high rates of CHD deaths in men in the United States spurred studies of potential dietary factors in the 1950s.
"By the 1960s, two prominent physiologists were championing divergent causal hypotheses of CHD: John Yudkin identified added sugars as the primary agent, while Ancel Keys identified total fat, saturated fat, and dietary cholesterol," Kearns and colleagues wrote. "However by the 1980s, few scientists believed that added sugars played a significant role in CHD, and the first 1980 Dietary Guidelines for Americans focused on reducing total fat, saturated fat, and dietary cholesterol for CHD prevention."
They noted that the sugar industry "steadfastly denies that there is a relationship between added sugar consumption and CVD risk," despite the ongoing debate of dietary sugars and CHD risk.
Kearns and colleagues identified correspondence between the Sugar Research Foundation and a professor, as well as correspondence between the foundation and the codirector of their first CHD research project, in addition to annual reports, internal reviews of research and symposia proceedings. They also reviewed relevant statements and reports issued by the National Academy of Sciences-National Research Council, U.S. Public Health Service, the American Heart Association and the American Medical Association from the 1950s and 1960s.
Their analysis showed that the Sugar Research Foundation began funding CHD research in 1965 and its first project, a literature review published in The New England Journal of Medicine, was published in 1967. The review, 'Dietary Fats, Carbohydrates and Atherosclerotic Disease,' focused on the role of dietary cholesterol and saturated fat and downplayed the role of sugar as a risk factor for CHD.
Correspondence between the foundation's director of research and a codirector of the project demonstrated how the Sugar Research Foundation guided the objective of the study, contributed articles to the review and received drafts, the authors wrote. However, the foundation's participation in and funding of the review was not disclosed.
Kearns and colleagues also found other examples of the sugar industry's funding of research, noting that it has previously influenced the National Institute of Dental Research and an FDA evaluation and currently criticizes evidence that links cardiovascular disease and sucrose. This indicates "the industry may have a long history of influencing federal policy," the researchers suggested.
They called for future reviews to be written by authors without conflicts of interest and clear financial disclosures, as the research informs further investigations and policy. Kearns and colleagues noted that the NEJM has required disclosures since 1984.
The researchers acknowledged that the did not find "direct evidence that the sugar industry wrote or changed the NEJM review manuscript" and that their report is based on circumstantial evidence.
"This study suggests that the sugar industry sponsored its first CHD research project in 1965 to downplay early warning signals that sucrose consumption was a risk factor in CHD," Kearns and colleagues concluded. "As of 2016, sugar control policies are being promulgated in international, federal, state and local venues. Yet CHD risk is inconsistently cited as a health consequence of added sugars consumption."
They continued: "Because CHD is the leading cause of death globally, the health community should ensure that CHD risk is evaluated in future risk assessments of added sugars. Policymaking committees should consider giving less weight to food industry-funded studies, and include mechanistic and animal studies as well as studies appraising the effect of added sugars on multiple CHD biomarkers and disease development."
In an accompanying editorial, Marion Nestle, PhD, MPH, from New York University, discussed the still-relevant harms of nutrition research and the "compelling evidence" discovered by Kearns and colleagues.
"Industry-sponsored nutrition research, like that of research sponsored by the tobacco, chemical, and pharmaceutical industries, almost invariably produces results that confirm the benefits or lack of harm of the sponsor’s products, even when independently sponsored research comes to opposite conclusions," she wrote. "Although considerable evidence demonstrates that those industries deliberately influenced the design, results, and interpretation of the studies they paid for, much less is known about the influence of food-company sponsorship on nutrition research."
Nestle noted that their report is a "smoking gun" that proves such influence and acknowledged that "the practice continues."
"In 2015, the New York Times obtained emails revealing Coca-Cola’s cozy relationships with sponsored researchers who were conducting studies aimed at minimizing the effects of sugary drinks on obesity," she wrote. "Even more recently, the Associated Press obtained emails showing how a candy trade association funded and influenced studies to show that children who eat sweets have healthier body weights than those who do not. The results of such studies have obvious implications for public health."
Nestle stated that industry-sponsored nutrition research compromises public health in a variety of ways and agrees with advice to view such research skeptically.
"Disclosure of funding sources helps but is not sufficient to address the potential conflicts that can occur with such funding," Nestle concluded. "These authors have done the nutrition science community a great public service by bringing this historical example to light. May it serve as a warning not only to policymakers, but also to researchers, clinicians, peer reviewers, journal editors, and journalists of the need to consider the harm to scientific credibility and public health when dealing with studies funded by food companies with vested interests in the results — and to find better ways to fund such studies and to prevent, disclose, and manage potentially conflicted interests."
The Sugar Association released a statement regarding the report, acknowledging that the foundation should have "exercised greater transparency in all of its research activities," but noting that today's standards differ from the period in question. The association also stated that "it is challenging for us to comment on events that allegedly occurred 60 years ago, and on documents we have never seen."
"Generally speaking, it is not only unfortunate but a disservice that industry-funded research is branded as tainted," they said in the release. "What is often missing from the dialogue is that industry-funded research has been informative in addressing key issues. We question this author’s continued attempts to reframe historical occurrences to conveniently align with the currently trending anti-sugar narrative, particularly when the last several decades of research have concluded that sugar does not have a unique role in heart disease."
The association continued: "Most concerning is the growing use of headline-baiting articles to trump quality scientific research—we’re disappointed to see a journal of JAMA’s stature being drawn into this trend. The Sugar Association is always seeking to further understand the role of sugar and health, but we rely on quality science and facts to drive our assertions." – by Chelsea Frajerman Pardes
Disclosures: Nestle reports salary from New York University that supports research, manuscript preparation and website. She also reports royalties from books, and honoraria and travel, from lectures about matters relevant to the editorial.
Perspective
Back to TopWalter Willett, MD, DrPH
The historical account is interesting in multiple ways.
Conflict-of-interest standards throughout the academic world have changed dramatically since the 1960s. It is an additional useful warning that industry funding is a concern in research, as it may bias what is published, and it is doubly a concern in reviews because this inevitably involves some judgment about interpretation of data. This is also a very strong reason why research should be supported by public funding rather than depending on industry funding. Unfortunately, with the steady decline in funding of research by Congress over the last decade, many investigators have had to accept industry funding or get out of research. The problem is getting worse, not better.
This is also interesting from a historical perspective because the standards for conflict of interest and disclosure were very different than today. As noted in the paper, it wasn’t until 1984 that NEJM implemented its disclosure rules, and also that for reviews, there could be no financial conflict of interest, even if it was disclosed. Thus, this review would presumably not be published by NEJM today, given its current standards, which are not universal among journals. The authors were certainly not punished by our school because they broke no rules; industry funding was standard practice at that time and disclosure was not required. Also, as the JAMA authors say, they do not know whether the industry funding actually influenced the conclusions of the review.
In part because of the history showing that industry funding can bias research, and can certainly lead to the perception of possible bias, I have avoided this.
This is also interesting historically because D. Mark Hegsted, PhD, and colleagues were struggling to interpret data that are much more limited than what we have today. I would agree with most of the interpretations of Hegsted and colleagues. What they describe as epidemiological evidence was very crude data on comparisons among countries and time trends. Overall, I would agree with their conclusion that there was not sufficient evidence to say that sugar was a causal factor in CHD risk, although there were suggestions that this should be studied further. They did not have the larger prospective studies that we have today: Trans fat was not on the radar screen, the importance of cholesterol subfractions was not appreciated, and the importance of carbohydrate quality was not documented or appreciated.
Given the data that we have today, we have shown the refined carbohydrates (glycemic load) and especially sugar-sweetened beverages are risk factors for CVD, but that the type of dietary fat is also very important (for example, Wang DD, et al. JAMA Intern Med. 2016;doi:10.1001/jamainternmed.2016.2417). The JAMA review had some errors, for example the statement that only Hegsted’s study showed that replacing saturated fat with polyunsaturated fat lowered blood cholesterol. Many studies had shown this, including those of Keys. In fact, Keys and Hegsted had developed competing equations based on meta-analyses describing the effects of types of fat on serum cholesterol levels, but both the equations showed that replacing saturated fat with polyunsaturated fat reduced serum cholesterol.
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