Had your appendix removed? Your Parkinson's risk may be 20% lower

The tiny organ, which is attached to and opens up to the end of the large intestine, can only contribute to a million Americans, the researchers say. Their study was published in the journal Science Translational Medicine.

"Parkinson's disease is multisystem disorder," said Viviane Labrie, senior author of the study and an assistant professor at the Van Andel Research Institute in Michigan. "And so there is likely to be many sites where Parkinson's disease starts, the [gastrointestinal tract] being one of them. For other people, it may begin in the brain. "

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

"In the last decade, it's becoming apparent that Parkinson's disease is not just a movement disorder," Labrie said in a podcast. One of the most common non-motor symptoms of Parkinson's is gastrointestinal tract issues, so some scientists believe the disorder might begin there, she said. In fact, the appendix contains a protein, alpha-synuclein, which is known to accumulate in the brains of Parkinson's patients, she noted.

Searching for connections between Parkinson's and the appendix, and 1.6 million people in Sweden. This general population has been shown to be associated with a 19.3% reduced risk of developing Parkinson's disease, according to the researchers.

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

"Alpha-synuclein is a protein that is able to move, it is able to move to neuron to neuron, and it has been shown that it can travel," Labrie said. Potentially, the protein of the vagus nerve connecting the gastrointestinal tract and the brain.

"If it was to enter the brain, it was possible that it could eventually lead to Parkinson's disease," she said.

The study earned applause from some and criticism from others.

Do not get an appendectomy to Parkinson's ward off, experts say

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

Beck, who was not involved in the study, said it lays the foundation for Parkinson's disease, including environmental factors. At the same time, he said, are people having bad gastrointestinal illness issues that lead to getting away from the brain and getting into the brain?

Overall, finding a link between the appendix and Parkinson's is significant, he said. "Understanding where that is coming from," Beck said.

"People who had their appendices removed in early life," said McConway, who was not involved in the research. "Any of these differences may be the cause of the decreased risk of Parkinson's disease in those who had their appendix out, rather than the removal of their appendix."

He said that it is "not the case that the cause has been established beyond the doubt" by the study.