Tip Sheets

Resources for reporting on the latest dietary guidelines and oral health

By Mary Otto

As federal officials recommend that Americans limit their sugar intake to help prevent systemic and oral disease, researchers continue to explore how the relationship between diet and tooth decay works.

A study in the February Journal of the American Dental Association (JADA) may offer new clues. Researchers in Mexico examined the prevalence of erosive tooth wear – the irreversible loss of dental hard tissue – in a group of adolescents.

The researchers used a food questionnaire to ask more than 400 teens about their consumption of fruit juice, sports drinks, sweet carbonated drinks and spicy and acidic foods. The adolescents were then examined for tooth wear.

The study found more than 30 percent of the teens had lost enamel. Researchers concluded that among the beverages and foods the students consumed, sweet sodas contributed to the most to the students’ tooth erosion.

Another paper in the February JADA looked at the diet-oral health connection from a different angle.

Research suggests that many children who are overweight face an elevated risk of tooth decay, wrote authors, Jane Zeigler and Christopher Hughes, both professors at Rutgers University.

Oral health professionals can play a role in addressing both pediatric obesity and tooth decay by incorporating weight screening into dental visits.

“Pediatric obesity is a public health concern requiring an interprofessional approach to care,” they wrote. “Routine weight screening of pediatric patients and early intervention through education and referral of patients to a registered dietician nutritionist and physician for more in-depth evaluation may help reduce disease risk.”

In their newly issued dietary guidelines for the nation, federal experts also hope to help address both systemic and oral disease by urging Americans to limit sugar to no more than 10 percent of daily calories consumed.

In announcing the new guidelines, they spoke about evidence linking sugar consumption to elevated risk of obesity, diabetes, cardiovascular disease and tooth decay.  

In an appendix to the dietary guidelines, they explained how they drew their conclusions about the relationship between sugar and tooth decay.

Resources included a systematic review conducted by the World Health Organization (WHO).

Last year WHO called upon countries to limit sugar intake as a way of addressing obesity and tooth decay worldwide.

“We have solid evidence that keeping intake of free sugars to less than 10 percent of total energy intake reduces the risk of overweight, obesity and tooth decay,” said Francesco Branca, director of WHO’s Department of Nutrition for Health and Development, said in a news release about the guidelines. “Making policy changes to support this will be key if countries are to live up to their commitments to reduce the burden of noncommunicable diseases.”

The organization found that a further reduction to below 5 percent or roughly 25 grams (6 teaspoons) per day would provide additional health benefits.

“Much of the sugars consumed today are 'hidden' in processed foods that are not usually seen as sweets,” WHO stressed in the release. “For example, 1 tablespoon of ketchup contains around 4 grams (around 1 teaspoon) of free sugars. A single can of sugar-sweetened soda contains up to 40 grams (around 10 teaspoons) of free sugars.”

Noting that oral conditions affect 3.9 billion people across the globe, authors of a major 2014 study published in BMC Public Health have made a case for the drastic reduction of sugars worldwide. The authors contended “the current approaches to controlling dental caries are failing to prevent high levels of caries in adults in all countries and this relates to the current high level of sugar intake across the globe.”

Tooth decay has been termed a multi-factorial disease, with diet playing a role along with oral bacteria and other host factors. Many studies have examined the workings of decay, and the role that diet plays in caries. The impact of sugar sweetened beverages, or SSBs have been widely researched.    

“Numerous studies …have linked SSBs with an increased risk of tooth decay among children, and some have found that the acidity levels commonly found in sodas and sports drinks erode tooth enamel,” summarized a Robert Wood Johnson Foundation research synthesis on the impact of sodas on children’s health. “Children who consume more soda and sucrose, which many SSBs contain, are at increased risk of decayed, missing and filled teeth.”

And here is one more interesting piece of related news.

In Mexico, where the JADA study found more than 30 percent of teens with eroded teeth, a soda tax imposed in 2014 may be working to reduce sugar consumption.

Over the first year the tax was in effect, sales of sugary beverages in the country fell by as much as 12 percent, a study has found. Meanwhile, bottled water purchases rose 4 percent, the New York Times reported.

Is your community discussing a soda tax? What do your local dentists have to say about weight screening as a way of addressing both tooth decay and obesity? Is there a new story about sugar and oral health that you can tell?