Blood is thicker than water: Flaws in a National Toxicology Program study

Municipal fluoridation was a mid-twentieth century innovation based on the medical hypothesis that consuming low doses of fluoride when young provided protection against cavities with only a small risk of mild dental fluorosis, a cosmetic effect. In the 21st century, more than half of American teens are afflicted by dental fluorosis with approximately one in five having moderate to severe dental fluorosis in at least two teeth. Scientific literature since the 1990s has found that even low doses of fluoride adversely affect cognitive-behavioral development and that deficits are correlated with the severity of dental fluorosis in afflicted individuals. Evidence of neurotoxic impact from low dose systemic exposure to fluoride prompted an investigation by a branch of the governmental agency that has promoted fluoridation policy since its 1940's inception. This review identifies ten significant flaws in the design of an animal experiment conducted by the U.S. National Toxicology Program as part of that investigation into the neurotoxic impact of systemic prenatal and postnatal fluoride exposure. The authors hypothesize that organizational bias can and does compromise the integrity of fluoride research.