Fluoride content of school lunches from an optimally fluoridated and a fluoride-deficient community

This study was conducted to compare contemporary dietary fluoride intake to surveys conducted a decade ago. It also served as a means of evaluating the difference in fluoride intake between residents of an optimally fluoridated and a fluoride-deficient community. Forty-four type A school lunches were collected from an optimally fluoridated (n = 24) and a fluoride-deficient (n = 20) community and analyzed for fluoride content. Fluoride analysis was accomplished using a microdiffusion technique to assay the acid-diffusible fluoride fractions. The mean total fluoride content of the lunches from the optimally fluoridated community was 227 μg. This was significantly higher than the mean fluoride content of 54 μg from the lunches in the fluoride-deficient community. The mean fluoride concentrations of the solid food from the optimally fluoridated and the fluoride-deficient communities were 0.53 and 0.23 μg fluoride/g, respectively. This difference was also statistically significant. The differences between the two communities in fluoride content of the lunches may be due to differences in the processing and cooking of the samples, primarily in the use of optimally fluoridated water for preparing some foods. In addition, the fluoride content of the lunches from the optimally fluoridated community was higher than expected on the basis of previous reports from similar communities. This difference may be related to differences in analytical techniques, changes in dietary habits, and an increase of fluoride in the food chain.