In the party that is your body, your appendix can seem like a wallflower. After all, you may not really notice your appendix until it gets inflamed. Then, it can get promptly removed. Otherwise what else does a dangling out-pouching from your large intestine really do?
Well, a study just published in Science Translational Medicine suggests the appendix may have more than meets the eye. Could microscopic findings in the appendix have something to do with the cause of Parkinson’s Disease?
As you may know, Parkinson’s Disease is a nervous system disorder that eventually affects the ability to move different parts of the body. Symptoms include shaking or tremors, muscle stiffness, slowing of movement, balance problems, and difficulty speaking and writing and can get progressively worse over time. These symptoms seem to result from the gradual loss of nerve cells in the brain that produce a neurotransmitter called dopamine. Neurotransmitters are chemicals that help pass electrical signals from nerve cell to nerve cell. Losing neurotransmitters disrupts these electrical signals and the movements that they govern. Actors Alan Alda and Michael J. Fox and singers Neil Diamond and Linda Ronstadt have raised needed awareness of Parkinson’s Disease by going public with their diagnoses.
Researchers are still trying to uncover the causes of Parkinson’s and this latest study offers some potential clues. Even though the damage in Parkinson’s Disease seems to be occurring in the brain, the research team led by Bryan Killinger and Viviane Labrie from the Van Andel Research Institute in Grand Rapids, Michigan, pursued a gut feeling. They wanted to further explore the theory that Parkinson’s Disease may start in the gut and then eventually climb into the brain.
How did this theory arise? Gastrointestinal symptoms like constipation can occur relatively early on in the course of Parkinson’s Disease. Also, cutting the vagus nerve used to be a treatment for stomach ulcers. The vagus connects the gut to the brain. There has been the observation that those who underwent such vagotomies seemed to have lower likelihood of eventually developing Parkinson’s. But again, the gut-brain connection for Parkinson’s Disease is still a theory without enough strong scientific evidence yet.
This newest study actually consisted of 3 parts. The first part involved analyzing data from the Swedish National Patient Registry (SNPR) and Statistics Sweden on 1.698 million individuals who had been followed for up to 52-years. Of them, 551,647 had undergone an appendectomy at some point their lives. These people were 19.3% less likely to eventually develop Parkinson’s Disease than those who never had their appendixes removed and a 16.9% less likely than the general population. For those who ended up developing Parkinson’s Disease. Among those who had had an appendectomy, 1.17 out of every 1000 people ended up having a Parkinson’s Disease diagnosis compared to 1.4 out of every 1000 in the general population.
Part two of the study entailed analyzing data on 849 Parkinson’s Disease cases from the Parkinson’s Progression Markers Initiative (PPMI). Those who had had an appendectomy at least 30 years before the diagnosis tended to develop Parkinson’s Disease at a later age, on average 3.6 years years later, than those who had never had an appendectomy.
The third part of the study took samples of the appendixes of 48 people without Parkinson’s Disease and used immunohistochemistry to look for a protein called α-synuclein. Prior studies have found accumulations of this protein in the substantial nigra, a part of the brain that helps control body movement, of people with Parkinson’s Disease. Indeed, the research team for this study found collections of α-synuclein in the sample appendix tissues. Additionally, the team found that the amount of α-synuclein was increased in 6 samples of appendixes from patients with Parkinson’s.
Are these study findings strong enough for you to get an appendectomy just to prevent Parkinson’s Disease? Absolutely not. This study doesn’t even prove that the appendix has any relation to Parkinson’s Disease. The first 2 parts of the study merely showed correlations or associations. And as I have said time and time again, associations do not prove cause-and-effect. Remember, there is an “ass” in associations if you believe they do. People who are more likely to get appendectomies may have very different surrounding situations or life courses than those who don’t.
Regarding the third part of the study, the role of α-synuclein in Parkinson’s Disease is still unknown. Could it somehow cause the damage in Parkinson’s Disease or could it be a byproduct? There is always the chance that it could be just a bystander. More research is needed to know.
This study is a reminder that the connections between the gut and the rest of the body are probably more complex than we realize. Having your head up your “you know what” may not be just a saying. Your brain and your intestines are connected in many different ways. And your intestines are not just like a tube of toothpaste. They may be playing many complex roles, ranging from regulating your metabolism to helping your immune system. That makes what you are putting in your mouth, whether it’s food, beverages, medications, or smartphones, even more important. Stay tuned as this study only begins to get into the guts of Parkinson’s Disease research.