The incidence of Parkinson’s disease which affects 100,000 Spaniards keeps going on the rise. This disease usually appears associated with people of more than 65 years of age (70% of the affected ones), but also appearing at a much younger age (30% of the cases, half of them at 45 and the other half even earlier). This is how, among the famous people who have suffered from it, there are cases like that of Muhammad Ali, Debora Kerr, or Katherine Kepburn, there are also cases like that of actor Michael J. Fox who was diagnosed as young as 30. Although it has been frequently said that this is a disease of an unknown cause—something lamentably applicable to many a common disease nowadays—in fact, there is a great deal of researches pointing to a certain number of likely contributing factors; among these and in a remarkable manner, jointly or not with other elements, the exposure to a series of environmental factors.
In this line, for instance, the Journal of the American Medical Association published a particularly eloquent article on Parkinson’s disease in identical twins. It was proved that even when one of the twins had Parkinson’s disease—despite the shared genome—the other twin would not have any greater chance of developing the disease than that of an average person. In short, Parkinson’s disease was not a genetic disorder, in most cases, but environmental factors were to be referred to, such as toxins.
A great percentage of the risk of developing Parkinsons’s disease may be attributable to environmental exposure.
Here it is important, as well, the Consensus Statement on Parkinson’s Disease and Environment subscribed by a team of experts on toxicology, epidemiology, genetics, neurosciences, and medical doctors stressing the same, that “A great percentage of the risk of developing Parkinson’s disease may be attributable to environmental exposure”, that only a small percentage, not higher than 10%, could be referred to genetic factors, and that “it is not only about developing more effective treatments, but also about prevention”.
It is not only about developing more effective treatments, but also about prevention.
Nevertheless, prevention is not something precisely dominating a great deal of modern medicine’s view when it comes to avoiding exposure to chemical contaminants. Something that triggered the thinking that there could be a relationship between Parkinson’s disease and the exposure to some chemical substances was the case with a substance called MPTP which is a subproduct emerging while producing some synthetic drugs. It was observed that some youths in Northern California who had been injecting themselves drugs contaminated with this specific compound were exhibiting Parkinson’s symptoms. Later on, this connection was confirmed when experimenting with monkeys.
Curiously, MPTP’s chemical structure is similar to that of some pesticides which made scientist intrigued. This led to numberless studies on the matter. Some of these studies, for instance, point to the fact that people exposed to herbicides may get to suffer up to four times more risk of developing the disease, and the people exposed to insecticides, up to 3.5 times more. The United States Center for Disease Control and Prevention assessed that farmers exposed to pesticides had a 2.8 higher risk of developing the disease.
A certain number of substances have been referred to as associated with Parkinson’s disease, with a more or less substantial evidence; among these, manganese (a metal very widely used in industrial production), MPTP (abovementioned), methanol, paraquat (one of the most worrisome, dubious pesticides), dieldrin, glyphosate (one of the most used pesticides the world over), lead, mancozeb, maneb (a pesticide containing manganese), organophosphorus and organochloride compounds, PCBs, etc.
The power of the evidence that a series of contaminants could influence on the development of the disease, far from waning, has been getting stronger every day. Thus, for instance, researchers of the universities of Duke and Miami have established an association between pesticides and Parkinson’s disease pointing to the fact that, even when some genes have been identified as predisposing to the disease, this would only be the case with a minor percentage of the affected ones; and, not only this, but that the only thing existing in such cases would be an interaction between the predisposing genes and environmental factors. Moreover, this interaction is a constant thing with other diseases, too, in which the genetic factors alone cannot account for the rapid expansion of a certain number of pathologies in the last decades.
The most diverse research has been made with the widest range of toxic substances in relation to this disease. Very interesting are, for example, those studies on the toxins found in the brain of dead people who had suffered Parkinson’s disease, as compared with the brains of other dead people who had not suffered the disease. The former presented considerably higher concentrations of toxins, such as organochloride pesticides, or PCB (polychlorinated biphenyl 153), among others.
Some of the scientific experiments show that, beyond the effect of the exposure to toxins such as pesticides along one’s life, the inflicted damage leading to the development of Parkinson’s disease may have occurred as early in life as during the intrauterine period due to the an exposure suffered by the mother, even when the most evident symptoms made their appearance at different ages later on. A greater effort towards prevention may be required here as that of banning the exposure to a series of contaminants, besides improving the treatments that, many times, only palliate the symptoms rather than cure the disease, for such as the saying goes: “Prevention is better than cure”.
Carlos de Prada
Director of “Hogar sin Tóxicos” (Toxin-free Home)
Author of the book “La Epidemia Química” (Chemical Epidemics) – Ediciones i
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