70 years after water fluoridation began, there remains a scarcity of research investigating the toxic effect of fluoride on liver function.
We do know that fluoride exposure at levels currently deemed safe by the US Environmental Protection Agency, .7 ppm, can damage liver function in children. Altered liver function can impact bodily fluoride absorption and metabolic processes. Children drinking water with more than 2 ppm fluoride, particularly those with dental fluorosis, were found to have increased levels of lactic dehydrogenase in their blood (an indicator of liver damage).
In 2006, researchers at Tongji Medical College in China studied fluoride exposure and liver function, stating that:
“A fairly substantial body of research indicates that patients with chronic renal insufficiency are at an increased risk of chronic fluoride toxicity. These patients may develop skeletal fluorosis even at 1 ppm fluoride in the drinking water.” (Dr. Helmut Schiffl, 2008)
Those researchers reported that liver damage in chronic fluoride intoxication was shown by Frada et al among persons with endemic skeletal fluorosis in Northern Sicily, and provided another reference to liver damage in chronic fluoride poisoning was made at an air pollution District trial in an Oregon court.
Because of the scarcity of research on fluoride’s effect on the liver, the National Academies of Science recommended that:
“The effect of low doses of fluoride on kidney and liver enzyme functions in humans needs to be carefully documented in communities exposed to different concentrations of fluoride in drinking water.”