Parkinson's disease has long been considered brain disease, but several studies have pointed to the role of the digestive system. The study published Wednesday in the United States is particularly interested in a small body that is considered unnecessary addiction.
The authors of this study, which are based on the 1.7 million Swiss medical records that have been following for half a century, have found that those who had the supplement removed early in life Parkinson's disease is reduced by 19%. The effect seems to be specific to Swedes living in rural areas. For them, the risk is reduced by 25%, while in urban areas there is no risk reduction.
As for those who have developed Parkinson's disease, researchers have found that apendectomy (removal of supplements) is associated with later on average three and a half years on average, said principal author Viviane Labrie, from the Van Andel research institute in Michigan during a conference call in print on Tuesday.
"Our work suggests that the supplement may play a role in the onset of Parkinson's disease," she explained, pointing out that this role is unlikely to be exclusive.
Parkinson's patients also suffer from gastrointestinal problems, such as constipation, decades or more prior to symptoms such as tremor and other motor problems. This has prompted the scientific community to become interested in the role of the digestive system.
The supplement is a place for intestinal bacteria storage and also seems to play a role in immune response. It is also a "container" of the key protein in Parkinson's disease, called alpha-sinuklein, especially in abnormal form.
But this protein is abundant in addition to all, ill or not. This suggests to researchers that an abnormal protein sometimes manages to escape from the finger to the brain, where this would cause damage.
"This protein does not like to stay in one place," Viviane Labrie said. "She moves from neuron to neuron".
And precisely, the nerve, the vagus nerve connects the digestive tract with the brain. Experiments have shown that the protein can take this time.
"If it enters the brain, it can be set up and developed until it has neurotoxic effects that can lead to Parkinson's disease," says the researcher.
The authors of the study warned journalists that it was not a recommendation to remove the add-on. "We do not say that if you had the removal, you will not have Parkinson's disease," warns Viviane Labrie.
But this work gives a further insight into the role of a small organ that could one day lead therapies to neutralize this reservoir.
Currently, the causal relationship has not been established. As with studies of this kind, many factors that did not take into account could explain the difference between those who were ablated and others.