For years, we didn’t really know what the appendix did. A person can survive without it, but it isn’t useless. It’s most likely plays some part in the immune system, and after a study published in 2018, we know that it may affect a person’s risk for Parkinson’s disease.
Viviane Labrie, a neuroscientist from the Van Andel Research Institute, and her team analyzed huge amounts of data gathered from a national registry of Swedes. Some of the people had been tracked for half a century, which was very useful. Long-term studies always provide better information than the short-term. It was a good sample of data, because over half a million people in the registry (out of 1.7 million) had their appendix removed, while over 2,000 of the total got Parkinson’s. What did the analysis reveal?

The appendix is a worm-shaped tube way down by the cecum
Overall, those who had their appendix removed had a 19.3% lower risk of getting Parkinson’s. Interestingly enough, those who lived in rural areas and got their appendix out had a much lower risk: it was 25%. However, in an urban environment, getting your appendix out didn’t significantly lower your Parkinson’s risk. There are other factors at play that may be countering the benefits of an appendix removal.
The scientists made another interesting discovery when they compared samples of healthy appendix tissue and tissue from the brains of those with Parkinson’s. Certain protein clumps were very similar. Is the tissue in the appendix somehow triggering Parkinson’s? Labrie believes those clumps might become deformed and eventually make their way through the nerve that connects the digestive system to the brain. Once there, it triggers Parkinson’s by blocking dopamine production.

The molecular structure of dopamine. When deprived of it, a person gets the definitive tremors and stiffness of Parkinson’s.
If Labrie’s hypothesis turns out to be correct, it makes sense that removing the appendix earlier in life could lower one’s risk for Parkinson’s down the line. Doctors may not even need to remove the appendix, however, if they could prevent a high amount of the protein clumps forming in the organ in the first place. While it doesn’t answer all of scientists’ questions, it does strength the idea that Parkinson’s is linked to the immune and digestive system. With more research, better therapies are bound to follow.