Methods: 780 subjects (Males =52.94%) aged 12 to 15 years were selected by household survey in nine villages having varying fluoride concentrations in drinking water (high 2.80 ppm, optimum 1.50ppm, and low 0.80ppm) from Davangere, India. Exposure ascertainment of Jowar consumption was done by 24-hour diet recall and Food frequency Questionnaire. The subjects were requested a mid morning spots urine samples (50ml) in non reactive plastic containers. Ion selective electrode method was used to estimate the fluoride level in spot urine samples of subjects and drinking water collected from villages. Independent sample t test were done to find the difference in urinary fluoride level using SPSS version 11.5.
Results: Jowar consumers were 50.51% (n= 394). The mean urinary fluoride level of subjects was 1.00±0.33 ppm, 1.39±0.63 ppm and 1.93±0.71 ppm in low fluoride (0.80ppm), medium fluoride (1.50ppm) and high fluoride (2.80ppm) villages respectively. The mean urinary fluoride level was significantly (p=0.001) less in Jowar consumers (1.24±0.54ppm) compared to non jowar consumers (1.51±0.75ppm). The difference in mean urinary fluoride level between jowar consumers {1.20± 0.50ppm (medium fluoride), 1.67±057ppm (high fluoride village)) and non jowar consumers (1.57±0.69ppm (medium fluoride)}, {2.25±0.75ppm (high fluoride village)} were consistently significant with increasing fluoride level in drinking water. The frequency of jowar consumption is negatively correlated with the mean urinary fluoride level among jowar consumers. There was no difference in urinary fluoride levels between sexes and ages.
Conclusions: The Jowar diet alters the metabolism of fluoride which tends to explain the enhanced effect of fluoride (dental fluorosis) among jowar consumers.