Fluoride ingestion and its correlation with gastrointestinal discomfort

Abstract

This study was carried out to assess the effect on the human gastroduodenal mucosa of drinking naturally fluoridated water and treating patients with 30 mg sodium fluoride for otosclerosis. Ten cases each of skeletal fluorosis and otosclerosis and twenty cases of non-ulcer dyspepsia (NUD) were investigated through routine clinical investigations, chemical investigations of body fluids and drinking water for fluoride, radiographs, stool examination for ova, cysts and worms, abdominal sonography, upper gastrointestinal endoscopy, jejunal aspirates for Giardia lamblia, histopathology of biopsies of intestinal and gastric mucosa and scanning electron microscopy of the mucosa. Patients of all three groups, compared with a control group of normal healthy volunteers, presented gastrointestinal problems and discomfort. Four patients with non-ulcer dyspepsia also presented radiological evidence of skeletal fluorosis. Analysis of ingested drinking water revealed fluoride concentrations of 0.49 - 11.36 ppm. Histopathological studies revealed non-specific lesions. Stool examination revealed ova of Ascaris lumbricoides in two NUD patients, while the rest had normal stool on examination. Jejunal aspirates were negative for Giardia lamblia in all the subjects. Scanning electron microscopic studies revealed widespread damage to the mucosa, viz. (a) mucus droplets were not visible, (b) loss of microvilli, (c) cracked-clay appearance of the duodenal mucosa and (d) desquamated epithelium of gastric mucosa. It is concluded: 1) Ingested fluoride damages gastroduodenal mucosa. 2) Gastrointestinal discomfort can be an early warning sign of fluorosis. 3) Fluoride toxicity should be considered a possible reason for non-ulcer dyspepsia, especially in fluorosis endemic areas. 4) Gastrointestinal discomfort during sodium fluoride therapy calls for extreme caution and close monitoring. 5) Gastrointestinal discomfort in the form of dyspeptic symptoms should be an important diagnostic feature when identifying fluorosis patients and should not be dismissed as non-specific.