How sugar industry influenced the National Caries Program research

Plos: Recnt findings highlight the need to carefully scrutinize industry opposition to the proposed WHO and FDA guidelines on sugar intake and labeling, respectively, to ensure that industry interests do not interfere with current efforts to improve dental public health.

Tooth decay (dental caries) is the leading chronic disease of children and adolescents. Although largely preventable, 42% of children in the US have some decay in their baby (primary) teeth, and 59% of adolescents have cavities in their permanent teeth. Tooth decay occurs when the hard enamel covering the tooth surface is damaged by acid, which is produced by bacteria in the mouth. Plaque, a sticky substance of bacteria, food particles, and saliva, constantly forms on teeth. When you eat food—particularly sugary foods and drinks—the bacteria in plaque produce acids that attack the tooth enamel. The stickiness of the plaque keeps the acids in contact with the teeth. Plaque buildup can be prevented by regular brushing and flossing. Dentists can detect tooth decay before it causes toothache through visual examination or by taking dental X-rays, and can treat the condition by removing the decay and plugging the hole with a “dental filling.” However, if the decay has damaged the nerve in the center of the tooth, root canal treatment or removal of the tooth may be necessary.

 

Why Was This Study Done?

Experts generally agree that sugars play a causal role in tooth decay. Consequently, in 2014, the World Health Organization (WHO) issued a draft guideline that recommended a daily limit on the consumption of “free” sugars (sugars added to food by manufacturers, cooks, or consumers). Also in 2014, the US Food and Drug Administration (FDA) proposed that the nutrition facts panels on US packaged food products should list added sugars. As with similar proposals made in the past, the World Sugar Research Organisation, a trade organization that represents companies with economic interests in sugar production, is challenging these proposals, arguing that, rather than trying to limit sugar intake, public health interventions to prevent tooth decay should focus on reducing the harms of sugar consumption. Here, the researchers explore how the sugar industry has historically sought to undermine or subvert policies to restrict sugar consumption, by examining internal industry documents related to the launch of a targeted research program to identify interventions to eradicate tooth decay—the National Caries Program (NCP)—by the US National Institute of Dental Research (NIDR) in 1971.

 

What Did the Researchers Do and Find?

The researchers analyzed an archive of 319 internal sugar industry documents from 1959 to 1971 (the “Roger Adams papers”) and NIDR documents to explore how the sugar industry sought to influence the setting of research priorities for the NCP. Their analysis indicates that, as early as 1950, sugar industry trade organizations had accepted that sugar damaged teeth and had recognized that the dental community favored restricting sugar intake as a key way to control caries. The sugar industry therefore adopted a strategy to deflect attention towards public health interventions that would reduce the harms of sugar consumption. This strategy included tactics such as funding research into enzymes that break up dental plaque and into a vaccine against tooth decay, and cultivating relationships with the NIDR leadership. Notably, 78% of a report submitted to the NIDR by the sugar industry was directly incorporated into the NIDR’s first request for research proposals for the NCP, and research that could have been harmful to sugar industry interests (specifically, research into methods to measure the propensity of specific foods to cause caries) was omitted from the research priorities identified at the launch of the NCP.

 

What Do These Findings Mean?

These findings, although limited by the researchers’ reliance on a single source of industry documents and by the absence of interviews with key actors in the launch of the NCP, reveal an alignment of research agendas between the NIDR and the sugar industry in the early 1970s. The findings also suggest that the NCP was a missed opportunity to develop a scientific understanding of how to restrict sugar consumption to prevent tooth decay. Indeed, although tooth decay declined by 20% between 1971/1973 and 1980, 64% of children still developed caries a decade after the NCP was launched. Most importantly, these findings illustrate how the sugar industry has protected itself from potentially damaging research in the past; a similar approach has also been taken by the tobacco industry. These findings highlight the need to carefully scrutinize industry opposition to the proposed WHO and FDA guidelines on sugar intake and labeling, respectively, to ensure that industry interests do not interfere with current efforts to improve dental public health.