Parkinson’s disease may originate deep in the digestive system, according to a new study by US scientists. The research, published in the journal Science Translational Medicine, found that people who had their appendix removed were less likely to develop this neurodegenerative disease. And the appendix, an organ whose usefulness remains in doubt, also proved to be a reservoir of the substances that kill brain cells.
In Parkinson’s disease, toxic proteins accumulate in the brain and kill nerves, especially those linked to movement. Although it may seem counterintuitive, there is growing evidence that the digestive system has a link to the disease. Professionals at the Van Andel Research Institute in Michigan, USA, analyzed data from 1.7 million people. The analysis revealed that the risk of developing Parkinson’s disease was 20% lower in people whose appendix had been removed.
The appendix is a small pouch located at the entrance to the large intestine. It is probably the best-known vestigial organ in the human body. An analysis of the contents of the appendix showed that it contains the same toxic protein, called alpha-synuclein, found in the brains of Parkinson’s disease patients.
Parkinson’s disease might originate in the appendix, but removing it is not wise, the researchers said
Viviane Labrie, one of the researchers, stressed that she does not recommend that people remove this organ. “We’re not promoting appendectomy as a way to protect against Parkinson’s disease. It would be much wiser to control or reduce the excessive production of alpha-synuclein to reduce its overabundance or potentially prevent it from escaping,” she said.
“This research is significant because it gives us one of the strongest evidence so far that Parkinson’s can start outside the brain, and this is a revolutionary idea that is beginning to emerge in the scientific world,” said Claire Bale of Parkinson UK. “Understanding where and how Parkinson’s disease originates will be absolutely crucial in developing treatments that can stop it and potentially prevent its” she added.
The study showed that almost everyone in this study had alpha-synuclein protein present in their appendix. Also, the scientists found some differences in protein structure between healthy people and people with Parkinson’s disease.