Parkinson's disease: the responsible appendix?

Many studies have already revealed that neurodegenerative diseases are related to the digestive system. But recently, a US study relayed in Science Translational Medicine suggests a new starting point for Parkinson's disease: the appendix.

Parkinson's disease affects about 200,000 people in France. Each year there are about 8,000 new cases in the territory. It is the second neurodegenerative disease after Alzheimer's with more than one million patients in Europe.

Digestive tract and neurological diseases

The neurological disease consists of a decrease in the production of dopamine, the neurotransmitter needed to control movement. It is characterized by a progressive loss of mobility, slower and steeper movements, limb tremors. It is on average around 58 years in France, and its causes are still poorly known.

That said, the digestive system is increasingly being studied as a potential cause. The US study published on November 1, which looked at 1.7 million Swedes, followed over a period of half a century, points to the appendix as a possible source of the disease. In particular, it raises the fact that people with early-life appendix surgery reduced their risk of developing Parkinson's disease by 19%.

A protein found in the appendix

The role played by the appendix, according to the researchers, in Parkinson's disease? It is a reservoir of toxins that stores a very important protein in triggering Parkinson's: alpha-synuclein. It is a protein that moves on neurons, forms aggregates, and its action destroys nerve cells little by little. His means of travel? The vagus nerve, the point of contact between the digestive system and the brain. Once reached the end of its course, it can generate neurotoxic consequences.

The study notes that not all carriers of this protein, even in large quantities, have all developed Parkinson's. The researchers believe that environmental factors also play a role in triggering the disease. This would explain that Swedes in rural areas, exposed to pesticides, have seen a 25% reduction in the risk of developing the disease after an appendectomy, while the results are much less convincing in the city.

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