Pesticides, cleaning products, contaminated food… Exposure to environmental toxins, inhaled or ingested, can cause predisposition to Parkinson’s disease, according to a study.
- Researchers suggest that Parkinson’s disease is the result of processes that begin either in the brain’s smell center (brain first), or in the digestive tract (body first), or both. But the cause would be common: exposure to toxic substances found in the environment.
- Pesticides, cleaning products, air pollution, but also contaminated food: exposure to environmental toxins can be the cause of the formation of the alpha-synuclein protein, the accumulation of which in the brain is a characteristic key to Parkinson’s disease.
- “Our study further reinforces the idea that the pathology can be fueled by toxic substances present in the environment, and therefore largely preventable,” say the authors.
In the nose or the intestines? While the question of the origin of Parkinson’s disease has tormented science for decades, researchers from American and Danish universities now argue that the neurodegenerative condition is the result of processes that begin either in the center of the disease. sense of smell in the brain, or in the digestive tract, or both.
The fact remains that the cause would be common: exposure to toxic substances found in the environment. Their work was published in the Journal of Parkinson’s Disease this April 11, on the occasion of World Pathology Day.
Parkinson’s disease: a link with inhaled and/or ingested toxins
The scientific community has known for 25 years that one of the key features of Parkinson’s disease is the accumulation in the brain of a misfolded protein called alpha-synuclein, which causes progressive dysfunction and death of nerve cells, including in regions that control motor function.
However, the new study argues that certain toxins encountered in the environment can be the cause of the formation of alpha-synuclein: this is the case of dry cleaning and degreasing chemicals based on trichloroethylene (TCE ) and perchlorethylene (PCE), but also paraquat, a herbicide widely used in agriculture, and more generally, toxins associated with air pollution.
When inhaled, in fact, these toxic substances can enter the brain via the nerve responsible for smell and, “from the olfactory center of the brain, alpha-synuclein spreads to other regions of the brain”can we read in a communicated. When ingested, for example through contaminated food or water, these toxins pass through the lining of the digestive tract and, “from the intestinal nervous system, alpha-synuclein spreads to the brain and spinal cord”.
The origins of Parkinson’s associated with environmental factors
“Our study suggests that Parkinson’s disease is a systemic disease that originates in the nose and intestine and whose roots are linked to environmental factors recognized as major contributors, if not causes, of the pathology, say the researchers. This further reinforces the idea that the disease may be fueled by toxic substances, and therefore largely preventable.” This, according to them, is the main interest of their work: encouraging prevention.
There remains one unknown in the equation: “These environmental toxins are very prevalent, and yet not everyone has Parkinson’s disease.” According to scientists, “the timing, level and duration of exposure, but also the interactions between genetic and environmental factors” could explain why certain people are more at risk of developing the pathology. There is always that “In most cases, these exposures surely occurred years or even decades before the first symptoms appeared.”
