Studies looking at the dangers of fluoride typically investigate its effects in isolation.
This can grossly underestimate the true risk as different neurotoxins in combination can result in greatly enhanced toxicological effects in a process known as synergism. In this 2023 study with 72 albino rats, researchers exposed animals to both fluoride and the pesticide rotenone in either isolation and in combination. Levels of exposure included that which could equal fluoride levels found in humans. When animals were exposed to both chemical compounds simultaneously, far greater levels of damage were detected compared to what each chemical was causing individually. This included a significant reduction in the critically important antioxidant glutathione, which functions to remove cell damaging free radicals and recently shown to detoxify environmental toxins as well. . Along with the reduction in glutathione, the two chemical combination was found to damage DNA in subsequent brain tissue analysis. The observation of fluoride causing increased damage to cells in combination with another chemical would suggest the true harm from fluoride is grossly underestimated and highlights the importance of incorporating synergism into future toxicological studies of neurological effects.
ABSTRACT:
Objective: Environmental toxins are known to be one of the important factors in the development of Parkinson's disease (PD). This study was designed to investigate the possible contribution of fluoride (F) exposure to oxidative stress and neurodegeneration in rats with PD induced by rotenone (ROT).
Materials and methods: A total of 72 Wistar albino male rats were used in the experiment and 9 groups were formed with 8 animals in each group. ROT (2 mg/kg) was administered subcutaneously (sc) for 28 days. Different doses of sodium fluoride (NaF) (25, 50 and 100 ug/mL) were given orally (po) for 4 weeks. Malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO), oxidative DNA damage (8-OHdG) and cholinesterase (AChE/BChE) enzyme activities were evaluated in serum and brain tissue homogenates.
Results: Rats treated with ROT and NaF had significant increases in serum and brain MDA, NO content, and decreases in GSH. In addition, the combination of ROT and NaF triggered oxidative DNA damage and resulted in increased AChE/BChE activity.
Conclusions: Findings suggest that NaF and ROT may interact synergistically leading to oxidative damage and neuronal cell loss. As a result, we believe that exposure to pesticides in combination with NaF is one of the environmental factors that should not be ignored in the etiology of neurological diseases such as PD in populations in areas with endemic fluorosis.