By the mid-1960s, scientists had identified both sugar and saturated fat as potential dietary risk factors for heart disease and early death.
By 1980, however — the year the first “Dietary Guidelines for Americans” was published — the role of sugar in heart disease was being discounted. Health officials had switched their focus almost exclusively to getting people to reduce their consumption of dietary fat.
Today, the link between heavy sugar consumption and heart disease is widely — although not universally — acknowledged. Most major health organizations, including the American Heart Association, warn against consuming too much of the sweetener.
So, what happened between 1965 and 1980? Why did concern about sugar suddenly disappear?
A troubling discovery
A new set of recently discovered documents provides a stunning — and troubling — answer. They show that, starting in 1965, a trade group for the sugar industry paid three influential nutrition professors at Harvard to downplay the association between sugar and heart disease.
The first effort from this group was a major literature review, published in two parts in the New England Journal of Medicine (NEJM) in 1967. In that review, the Harvard professors apparently cherry-picked the research to not only understate the role of sugar in the development of heart disease, but also to overstate the role of fat.
Because the review came from such prominent researchers, it helped to shape dietary recommendations for decades — and with devastating results. In fact, many health officials and others believe that the minimization of the unhealthy role of sugar in the diet has been a major factor in the obesity and diabetes epidemics.
The Harvard researchers’ financial ties to the Sugar Research Foundation, now known as the Sugar Association, were not revealed in the NEJM article. That journal did not require such disclosures until 1984.
More public relations than science
The Harvard professors who wrote the 1967 NEJM literature review were Frederick Stare, chair of Harvard’s School of Public Health Nutrition Department, and two of his departmental colleagues, David Mark Hegsted and Robert McGandy. Hegsted later became head of nutrition at the United States Department of Agriculture.
All three men have died, and thus were not interviewed by the authors of the JAMA Internal Medicine paper. Its authors also stress that there is no direct evidence in the newly discovered documents that sugar industry officials wrote or changed the Harvard professors’ NEJM manuscript.
Yet, “the documents leave little doubt that the intent of the industry-funded review was to reach a foregone conclusion,” writes Marion Nestle, a professor of nutrition and food sciences at New York University, in a commentary that accompanies the article. “The investigators knew what the funder expected, and produced it. Whether they did this deliberately, unconsciously, or because they genuinely believed saturated fat to be the greater threat is unknown. But science is not supposed to work this way. The documents make this review seem more about public relations than science.”
A continuing problem
This troubling 50-year-old incident is relevant today, Nestle argues, for it provides yet more evidence of how food companies have manipulated research over the years to favor their products.
“And the practice continues,” she writes. “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. 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.”
“Today, it is almost impossible to keep up with the range of food companies sponsoring research — from makers of the most highly processed foods, drinks, and supplements to producers of dairy foods, meats, fruits, and nuts — typically yielding results favorable to the sponsor’s interests,” Nestle adds.
A need for more skepticism
The USCF researchers urge health officials to be skeptical of industry-funded studies and to make sure that heart disease risk is included in all future risk assessments of added sugars in the diet.
“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 [coronary heart disease] biomarkers and disease development,” they conclude.
“These authors have done the nutrition science community a great public service by bringing this historical example to light,” writes Nestle. “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.”