The Not-So-Sweet Link Between Oral and Systemic Health

Dr. Richard ValachovicIn this month’s letter, Dr. Rick Valachovic, ADEA President and CEO, shares new evidence of sugar’s harmful health effects and asks how the dental education community might capitalize on growing public interest in limiting sugar intake.

Public willingness to address the health effects of sugar may be reaching a tipping point. Last month, the city of Philadelphia passed a tax on sugar-sweetened beverages, becoming the first major U.S. city to overcome resistance to such a measure. Berkeley, California’s residents passed a comparable tax in 2014, but according to the New York Times, this liberal enclave’s success was unique. Forty other municipal and state government attempts to pass similar measures all failed—until now.

Philadelphia’s soda tax—which proponents framed not as a public health measure but as a revenue generator for universal preschool—has given hope to advocates who are alarmed about the nation’s obesity epidemic and the growing body of scientific evidence linking excess sugar consumption to a range of systemic ills.

The World Health Organization (WHO); celebrity chef Jamie Oliver; and former Mayor Michael Bloomberg, who attempted to ban the sale of large-size sugar-sweetened beverages in New York City, have all brought much-needed attention to the hazards of sugar consumption, but no one has beaten the anti-sugar drum quite so steadily as Robert Lustig, M.D., M.S.L., a Professor of Pediatrics in the Division of Endocrinology and a member of the Institute for Health Policy Studies at the University of California, San Francisco. Dr. Lustig authored the best-selling book Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease and now serves as President of the Institute for Responsible Nutrition, a nonprofit organization dedicated to reducing the nation’s appetite for sugar.

This past April, Dr. Lustig gave the opening keynote address at the National Oral Health Conference. The title of his presentation was “Tooth Decay and Liver Decay: The Nexus Between Doctors and Dentists.” You can find his slides online if you want a more detailed explanation, but the bottom line is this—added sugars in our diets cause both dental caries and liver disease.

Dr. Lustig doesn’t mince words about the severity of sugar’s impact on human health. In his view, sugar is a “toxic” substance every bit as dangerous as alcohol. He believes public policies should limit the availability of the first just as they do the availability of the second.

I’ll leave it to our endocrinologist colleagues to evaluate Dr. Lustig’s assertions about liver disease, but his points about caries are more than familiar. I saw the effects of sugar first hand as a pediatric dental resident at Children’s Hospital in Boston. It’s hard to imagine now, but the city lacked community water fluoridation at that time, and we saw high levels of childhood caries as a result.

Jessica Lee, D.D.S., M.P.H., Ph.D., Chair and Director of Research for the pediatric dentistry department at the University of North Carolina at Chapel Hill (UNC) School of Dentistry, is outspoken about the need to address sugar’s causal role in tooth decay. She and Beau Meyer, D.D.S., pediatric dental resident, co-authored a commentary in the October 2015 issue of the Journal of Dental Research calling on policymakers to “be courageous” in developing policies to curb sugar intake and urging the scientific community to raise its voice in support of evidence-based policies.

I reached out to get their thoughts on what the dental education community should be doing to raise awareness among students about the effects of sugar on both dental and overall health. Beau, who is currently pursuing a Master of Public Health degree at UNC, told me they would like to see more emphasis on advocacy in the predoctoral curriculum.

“That goes beyond telling students they need to be advocates and meet with their Congressmen,” Beau said. “I’d like to see something that gets down to the nuts and bolts.” He envisions interprofessional workshops, field experiences and informal opportunities to “lunch and learn” that would teach students how to interact with a legislator, make that first phone call, find appropriate resources and build on established relationships between the state dental society and state legislators. But his vision extends beyond these practical concerns.

“Learning how to see beyond the patient in your chair and look at your practice and how it fits into the community as a whole—it’s a different way of thinking,” he told me, “and it’s a challenging way to think.”

Jonathan Shenkin, D.D.S., M.P.H., couldn’t agree more. Jonathan is Clinical Associate Professor in the Departments of Pediatric Dentistry and Health Policy & Health Services Research at the Boston University Henry M. Goldman School of Dental Medicine.

“When I talk to dental students, I beg them not to think of their futures as treating the patients who walk through the doors,” Jonathan told me. “Being able to change policies so you can improve the health of everyone, not just the people who pay you—it’s the most critical thing we teach students.”

Not surprisingly, Jonathan is excited by the implementation of the soda tax in Philadelphia, and believes such measures will begin catching on around the country. He sees an opportunity for dental professionals to join in this effort to curb sugar consumption and hopes it will have the same impact that tobacco taxes had on smoking.

“We have parallel etiology—sugar—for obesity and for tooth decay. This is a great opportunity to engage the public health and medical communities in helping our patients address the obesity crisis and the oral health crisis at the same time. It can only be positive,” Jonathan believes.

I agree, but given all the attention currently focused on sugar’s contributions to obesity and other aspects of overall health, the challenge may be to keep tooth decay in the conversation. There’s no doubt that it deserves the attention of the dental community. In the same issue of the Journal of Dental Research mentioned earlier, two London-based researchers remind readers that “free sugars” (those found in processed foods, syrups and juices) are the principal (and in their view, the only) cause of caries. They argue that our focus on the other factors—fluoride, bacteria—that mitigate and feed the disease, have taken our eye off the primary culprit. The authors conclude, “Dental caries is a diet-mediated disease,” and they add that “to stress the multifactorial effects on the sugars-induced causal process muddies our understanding and misdirects policy.”

Might it also suggest that we need to reevaluate the role of nutrition and its relationship to the oral-systemic connection in our curricula? I called Rebecca Wilder, B.S.D.H., M.S., another Professor at the UNC School of Dentistry who serves as Director of both Faculty Development and Graduate Dental Hygiene Education. She and her colleagues conducted a survey of North Carolina dentists and dental hygienists to ascertain their knowledge, attitudes and practice behaviors related to oral-systemic disease. They found that respondents were generally knowledgeable but often fell short when it came to putting their knowledge into practice.

“In dental hygiene, we’ve observed these connections for years,” Rebecca told me. “To finally have some science to say yes, these connections have been validated, has been a relief in some respects. Now the challenge is figuring out how to incorporate this into patient care.”

She is encouraged by the recent willingness of pediatric dentists to counsel the parents of their overweight patients about the risks associated with obesity, and she sees room in the curricula to encourage similar efforts for oral-systemic disease.

“I could envision an interprofessional course on oral-systemic disease where sugar is discussed extensively. Students would learn about its detrimental effects—not only orally, but systemically—so they could collaborate on patient care and patient education in the future. Once we have evidence-based knowledge, we have to take the onus as professionals to be assertive and talk to our patients about these issues.”

This fall, I’ll be attending a conference sponsored by a coalition of oral health and pediatric groups with support from the Robert Wood Johnson Foundation. The goal of this meeting is to engage the oral health community in efforts to prevent childhood obesity. Judging from the preliminary agenda, sugar-sweetened beverages will take center stage.

As for the value of soda taxes, it’s too soon to know what their impact will be on the residents of Berkeley or Philadelphia, but we might infer a few things from our neighbor south of the border. Mexico leads the world in soda consumption, and its rates of obesity and diabetes are similar to those in the United States. After Mexico instituted a tax on sugar-sweetened beverages at the start of 2014, researchers at UNC and Mexico’s National Institute of Public Health found a 6% drop in soda purchases compared with previous years. Mexican cola bottlers begged to differ, citing rising sales, but the researchers are sticking by their methodology and offer even brighter news for 2015. They say soda sales were 8% lower than pre-2014 averages, and bottled water purchases were up 4%. In the years ahead, I’ll be watching to see whether the incidence of caries falls as well.

Related content from previous issues of Charting Progress

Setting the Record Straight on Fluoride
Managing Caries Risk: A Paradigm for the 21st Century? 

1 comment
  1. Trisha OHEHIR said:

    Thank you Dr. Valachovic for shedding light on the sugar issue for dental and dental hygiene educators. Sugar is the link between oral and systemic disease and this information is missing from both undergraduate and graduate dental education. Sugar and fermentable carbohydrate consumption leads to dental disease followed by systemic disease. Dental disease is the alarm bell for future diabetes, heart disease, cancer and obesity. This is an entirely new concept for clinicians and one that is difficult to swallow – based on the amount of sugary treats found in dental office break rooms. 🙂

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