The U.S. Food and Drug Administration might soon decide to put a cap on daily sugar intake to help Americans cut down on it. Pixabay

Sugar companies played a large role in shaping early federal research policy on dental care in ways that still hinder American public health, according to an analysis of hundreds of documents tracing an industry advisor's correspondence from the late 1960s. The documents show a clear link between the industry's suggested research priorities and those adopted by a federal program created to research tooth decay prevention.

Though producers acknowledged as early as the 1950s that sugar is linked to tooth decay, industry leaders refuted suggestions that Americans should cut back on sugar. Instead, they promoted investment in the development of sealants and a tooth decay vaccine so as not to conflict with the marketing of their products.

Meanwhile, the industry leveraged its close ties to the National Institute of Dental and Craniofacial Research (NIDCR) to ensure that federal research funding reflected its priorities. The methods the sugar industry deployed to win favor with federal agencies are similar to those that the tobacco industry relied on to push its pro-smoking agenda at the time.

The researcher who uncovered the documents says the priorities set by the sugar industry in the late 1960s have had long-lasting effects on how sugar fares in federal policy on nutrition and dental health. Today, sugar lobbyists are challenging scientifically based recommendations put forth by the U.S. government to limit sugar intake and more clearly label its presence in foods.

Dr. Cristin Kearns, a dentist and postdoctoral researcher at the University of California, San Francisco (UCSF), accessed the records of Roger Adams, a chemist and former advisory board member of a leading industry group known as the International Sugar Research Foundation, through a public archive housed at the University of Illinois. Adams’ private correspondence provided a window into the methods lobbyists used to shape an initiative to fight cavities and other cases of tooth decay called the National Caries Program of the NIDCR, a division of the National Institutes of Health, in the late 1960s. Kearns outlined her research in an article published Tuesday in PLOS Medicine.

As early as 1950, the sugar industry admitted that sugar caused tooth decay, according to an annual report of the Sugar Research Foundation, a predecessor of the organization that Adams served. “There is evidence tending to show that carbohydrates, including sugar, and perhaps other food types, are implicated in tooth decay,” the report states.

The authors of that same report also outlined a pro-sugar research agenda that would be closely followed for decades to come, and largely adopted by federal researchers. Instead of limiting sugar intake – perhaps the simplest, cheapest and most effective way to avoid the associated tooth decay – leading sugar organizations partnered with the chocolate and confections industries to sponsor research on ways to prevent tooth decay while still allowing people to continue eating as much sugar as they wished. Or, as the annual report put it, “The ultimate aim of the Foundation in dental research has been to discover effective means of controlling tooth decay by methods other than restricting carbohydrate intake.”

Years later, when federal administrators at agencies including the NIDCR (then known as the National Institute of Dental Research) began to hint that they were interested in funding research to prevent cavities, the sugar industry began to push harder for an agenda to fight tooth decay through technologies that would eliminate the agencies’ need to suggest a reduction of sugar as part of a tooth-friendly diet.

To advance that idea, the Sugar Research Foundation co-sponsored a project to study enzymes that would break up the plaque that forms on teeth and traps in the harmful acids acquired by eating sugary substances. The group also funded attempts to develop a vaccine against tooth decay. The project’s leader, Bertram Cohen from the Royal College of Surgeons of England, once explained his research focus by saying, “Why should people be denied pleasure? It would obviously be far better to eliminate the harmful effects,” according to Kearns’ findings.

Eventually, that approach also made its way into the agenda set by federal researchers for the National Caries Program, which was meant to investigate the causes of tooth decay and develop ways to prevent it. Kearns’ research suggests a private-public overlap may have grown from a series of meetings separately held by the steering committee of the National Caries Program and a task force on tooth decay convened by the International Sugar Research Foundation. Both groups met in October 1969, and every member of the federal program also served on the industry’s task force -- except for Robert J. Fitzgerald, a microbiologist at NIDCR whose research had helped to establish the link between sugar and tooth decay.

Not long after, the NIDCR adopted a set of research priorities that closely reflected those proposed by the industry. In fact, an analysis that Kearns ran of the two proposals showed that 78 percent of the industry’s recommendations were “directly incorporated” into the NIDCR’s research outline for the National Caries Program in 1971. Fully 40 percent of the language that appeared in the federal program’s outline was lifted verbatim from or closely paraphrased the industry document. These priorities emphasized the need for research into enzymes, tooth decay vaccines and protective sealants.

“It was pretty shocking to see three-fourths of the sugar industry report incorporated into our most venerable research institution, which is funded by taxpayer dollars and not acting in the public's best interest," Kearns says.

The industry's success was celebrated in a document sent to Adams and other advisory board members by the International Sugar Research Foundation right before the NIDCR's research priorities were made public. "The correlation between sugar and tooth decay -- a practical concern of the sugar industry for many years -- may become a purely academic issue within the foreseeable future," the report stated.

This connection brings to light the role of the sugar industry in shaping federal research priorities decades ago – an influence that Kearns says still weighs heavily on the government's recommendations for sugar intake.

Since the government has hesitated to highlight the direct link between sugar intake and the risks of tooth decay, the responsibility for making that connection has fallen largely to parents and dentists.

“I think the dental community has always been behind restricting sugar intake -- no one would argue with that -- but it’s really fallen to individual dentists to educate their patients,” she says. “We haven't really had any federal policy to help consumers be aware of how much sugar they’re actually eating." Still today, tooth decay remains the most common chronic disease in children and adults in the U.S., according to the NIDCR.

Only this year, a federal advisory committee has suggested the nation’s dietary guidelines recommend that Americans cut back their intake of added sugars to no more than 10 percent of total calories consumed in a day, and the Food and Drug Administration is considering whether “added sugars” should be listed in a separate line on nutrition labels. The Sugar Association, a leading industry group that spun off from the Sugar Research Foundation but has engaged in similar work, has opposed both measures along with other industry groups.

The Sugar Association responded to Kearns’ research by referring to a passage from the U.S. Dietary Guidelines for Americans that deflects blame for tooth decay onto non-fluoridated bottled water. “We question the relevance of attempts to dredge up history when decades of modern science has provided answers regarding the role of diet in the pathogenesis of dental caries,” the organization said in a statement. “The reality is experts in this field agree: Cavities are lessened by a combination of smart snacking choices, whether sugar, starches, juices or any other fermentable carbohydrate; and responsible dental care, particularly reducing the time of carbohydrate exposure to the teeth before brushing.”

Kearns draws a parallel between the tactics of the sugar industry and those of the Tobacco Industry Research Committee, the group formed by tobacco companies in 1954 to counter claims that its products were harmful, with industry sponsored scientific research focused on dispelling safety concerns without scaling back sales. Kearns’ co-author, Dr. Stanton Glantz, a researcher focused on tobacco control at UCSF, once helped reveal the role of the tobacco industry in shaping public health and has assisted with the publication of 80 million pages of industry documents in the Legacy Tobacco Documents Library housed by UCSF.

"Our findings are a wake-up call for government officials charged with protecting the public health, as well as public health advocates, to understand that the sugar industry, like the tobacco industry, seeks to protect profits over public health," Glantz said in a statement.

The NIDCR, which invested $37 million into research on tooth decay in 2014, says that today the sugar industry may only weigh in on research priorities and policies through the agency’s public comment process. “There are many protections in place to make sure there are no conflicts of interest among the researchers or others advising the Institute,” Dr. Lillian Shum, director of research grants for NIDCR, says. She adds that while the agency does publish educational materials that recommend limiting sugar intake in order to maintain dental health, the agency also suggests other measures including protective sealants and regular visits to a dentist as part of a holistic approach.

Kearns says she hopes her work will bring industry interests to light at a critical time for public health, and while 92 percent of adults suffer from some form of tooth decay, according to the NIDCR. She supports the FDA’s revised nutrition label and the suggestion made by the advisory committee to place a limit on the amount of added sugars in a healthy diet. "We have another shot at it here,” she says.