Overweight kids have fewer cavities, new study shows

Surprised researchers at the Eastman Dental Centre, part of the University of Rochester Medical Centre in the United States, conducted a secondary analysis of nearly 18,000 children who participated in two separate National Health and Nutrition Examination Surveys (NHANES III and NHANES 99-02).

The study found no differences in rates of caries (tooth decay) among children ages 2-5 in all weight ranges, while children ages 6-18 who were considered overweight and at risk for becoming overweight showed a decreased risk of caries compared to their normal weight peers.

“We expected to find more oral disease in overweight children of all ages, given the similar causal factors that are generally associated with obesity and caries,” said Eastman Dental Centre's Dorota Kopycka-Kedzierawski, DDS, MPH, the lead author.
“Our findings raise more questions than answers. For example, are overweight children eating foods higher in fat rather than cavity-causing sugars? Are their diets similar to normal weight peers but lead more sedentary lifestyles? Research to analyse both diet and lifestyle is needed to better understand the results.”

The study defined overweight children as being at the 95th or higher percentile for their age and sex; children at the 85th or higher percentile and less than 95th percentile for their age and sex were defined as at risk for becoming overweight.

A world leader in residency training and research initiatives, the Eastman Dental Centre each year treats thousands of Rochester-area patients by providing a full range of general and specialised dentistry including paediatrics, periodontology, oral and maxillofacial surgery, orthodontics and prosthodontics. Established in 1941, the Eastman Dental Centre is the only major post doctoral dental education, research and clinical institution in the U.S. within an academic medical centre.