Aug. 25, 2023 – A large, well-designed new study links Parkinson’s disease with gastrointestinal problems.
Parkinson’s is the second most common neurodegenerative disease in the U.S. after Alzheimer’s disease. An estimated 90,000 people each year are newly diagnosed with it.
The most common symptoms affect a person’s movements and can result in tremors, slowed movement, or trouble walking. The Parkinson’s Foundation estimates 1 million people in the U.S. have the disorder, which can also cause sleep problems, depression, and speech issues.
This latest study was published Thursday in the journal Gut. Researchers sought to investigate a theory known as Braak’s Hypothesis that suggests sporadic Parkinson’s disease is caused by a pathogen that enters the body through the nose, is swallowed, and then enters the gut. The pathogen could be a virus, bacteria, or some other microorganism.
Researchers compared health records for 24,624 people with Parkinson’s disease in the U.S. to more than 8 million people without Parkinson’s who were matched as having similar demographics.
Comparisons were also made to people with cerebrovascular disease, which includes strokes, aneurysms, and Alzheimer’s disease. These conditions already have established associations with the gastrointestinal tract.
Researchers found that people diagnosed with Parkinson’s were significantly more likely to have experienced four specific GI conditions leading up to a Parkinson’s diagnosis.
Specifically, researchers found that having:
- Gastroparesis, also known as delayed gastric emptying, more than quadrupled the odds of developing Parkinson’s.
- Swallowing difficulties, known as dysphagia, more than tripled the odds of developing Parkinson’s.
- Irritable bowel syndrome without diarrhea also more than tripled the odds.
- Constipation also more than tripled the odds of developing Parkinson’s.
The study also showed that having an appendectomy appeared to result in protective benefits.
“These findings warrant alertness for GI syndromes in patients at higher risk for [Parkinson’s disease] and highlight the need for further investigation,” the authors wrote.