Facteurs environnementaux impliqués dans la maladie d'Alzheimer. Le mercure dentaire, probable déterminant majeur

Seen as a real sanitary curse in developed countries, Alzheimer's disease is about to create pandemonium on a worldwide scale. The outburst of this epidemic cannot only be explained by the ageing population and could, in decades to come, severely jeopardize the social security systems. The causes of this pathology are still largely unknown but epidemiological studies have proved the importance of environmental factors, whose effects depend on the presence of disease susceptibility genes. Numerous publications have underlined in particular the influence of toxic factors of chemical or physical kind: metals (mercury, lead, aluminum…), pesticides, electromagnetic waves… Among these risk factors, exposure to elemental mercury, whose main source is found in dental amalgams, seems to be particularly implicated. Indeed, scientific tests have clearly indentified that inorganic mercury induces harmful biological effects in the brain that can be compared to those observed in Alzheimer's patients. Several mechanisms explaining these disturbances have now been clearly identified: induction of oxidative stress, destruction of neuronal cytoskeleton, inhibition of the activity of enzymes which play a vital role in brain functions, disturbances in glutamate - a neuromediator - metabolism, etc. Research must therefore be more orientated towards the identification of the causes of this illness and not only towards palliative therapies such as drugs and vaccination. The level of our exposure to mercury and other neurotoxic substances can only be reduced by rapidly applying the precautionary principle, therefore delaying cerebral ageing.