Was your appendix removed? Your risk of Parkinson's can be reduced by 20%

This can be painful, but appendicitis can present an unusual benefit: people whose appendix has been removed have 20% less risk of developing Parkinson's disease.

This can be painful, but appendicitis can present an unusual benefit: people whose appendix has been removed have 20% less risk of developing Parkinson's disease.

It can be painful, but appendicitis may have an unusual benefit: people whose appendix has been removed have a 20% lower risk of developing Parkinson's disease, according to a new analysis involving more than one million people in Sweden.

The researchers explain that this tiny organ, which attaches to the lower end of the large intestine, opens up on this brain disorder that affects nearly a million Americans. Their study was published Wednesday in the journal Science Translational Medicine.

"Parkinson's disease is a multisystemic disorder," said Viviane Labrie, lead author of the study and assistant professor at Michigan's Van Andel Research Institute. "And so, there will probably be many original sites for the onset of Parkinson's disease, the [gastrointestinal tract] to be one of them. For other people, this can start in the brain. "

"Not just a movement disorder"

Parkinson's disease is not only common, with 60,000 new diagnoses each year, it is also incurable. Symptoms include tremors or tremors of fingers, hands, legs, or feet; rigidity; difficulty balancing; depression; and gastrointestinal disorders, including constipation. Research has shown that gastrointestinal symptoms can begin up to 20 years earlier than movement symptoms.

"Over the past decade, it has become clear that Parkinson's is not just a movement disorder," Labrie said in a podcast. One of the most common non-motor symptoms of Parkinson's disease is the condition of the gastrointestinal tract. Some scientists believe that the disease could start there, she said. In fact, the appendix contains a protein, alpha-synuclein, which is known to accumulate or clump in the brain of patients with Parkinson's disease, she noted.

In search of links between Parkinson's and the appendix, Labrie and her colleagues analyzed the medical data of 1.6 million people in Sweden. This survey of the general population showed that an appendectomy is associated with a 19.3% reduction in the risk of developing Parkinson's disease, according to the researchers.

Separately, they reviewed the records of 849 Parkinson's patients and found that an appendectomy was associated with the delayed onset of disease by 3.6 years on average.

"Alpha-synuclein is a protein that does not like to stay in place. He is able to move from one neuron to another and has been shown to travel, "said Labrie. The protein may eventually ascend the vagus nerve connecting the gastrointestinal tract and the brain.

"If it were to enter the brain, it would then germinate and spread, causing neurotoxic effects that could eventually lead to Parkinson's disease," she said.

The study has been applauded by some and criticized by others.

Do not do an appendectomy to rule out Parkinson's, experts say

James Beck, chief scientist at Parkinson's Foundation and associate associate professor in the Department of Neuroscience and Physiology at New York University School of Medicine, said the new study was "solid."

Although research shows that the disorder "may start in the gut," he said, "this is not an indication that people should have an appendectomy if they are worried about Parkinson's disease."

Beck, who did not participate in the study, said it would lay the groundwork for further research on other factors contributing to Parkinson's disease, including environmental factors. At the same time, he said, research raises issues such as: people with severe gastrointestinal illness that can cause proteins leaving the intestine and entering the brain?

Overall, finding a link between the appendix and Parkinson's disease is important, he said. "Understanding where these 20% come from could be helpful as part of a larger program for all people with Parkinson's disease," Beck said.

Kevin McConway, Emeritus Professor of Applied Statistics at the Open University in the United Kingdom, told the Science Media Center that the study was "competent", but he also made a critique based on the use of statistics by researchers .

"The people whose appendix was removed early in their life will, on average, be different from those who have not been removed in many ways," said McConway, who said not participated in the research. "Any of these differences could be responsible for lowering the risk of Parkinson's disease among those whose appendix was removed, rather than removing the appendix."

The study revealed that "it is not the case that the cause and effect have been established undoubtedly".