Does Having Your Appendix Removed Cause Parkinson’s?

There’s a link between appendicitis and Parkinson’s disease, according to a study published this week.

The new research, set to be presented at a conference next weekend, says a person is nearly three times as likely to develop Parkinson’s disease if they’ve had their appendix removed.

Appendicitis, or inflammation of the appendix, is a common condition that causes abdominal pain. It’s usually treated with an appendectomy—surgical removal of the appendix, which isn’t a vital organ.

To be clear, though, your chances of getting Parkinson’s disease are slim to begin with. Having an appendectomy makes them only slightly higher, according to the new research. Dr. Sheriff’s team analyzed the health records of more than 62 million people in the US. They looked at how many of the 488,190 patients who had received an appendectomy went on to develop Parkinson’s at least six months after the procedure.

The answer to that question was 4,470. In other words, 0.92% of the patients who had received an appendectomy went on to develop Parkinson’s at least six months later. The number of patients who did not undergo an appendectomy totaled 61.7 million. Only about 0.29% of those patients developed Parkinson’s. This means the increase in your chances of developing Parkinson’s if you’ve had your appendix removed is slight, jumping only from 0.29% to 0.92%.

But the new study might give doctors a better understanding of how Parkinson’s develops. “This research shows a clear relationship between the appendix, or appendix removal, and Parkinson’s disease, but it is only an association,” Dr. Sheriff said. He added that additional research is essential in order to confirm the relationship between appendicitis and Parkinson’s.

Parkinson’s is expected to affect 930,000 people in the US by 2020, according to the Parkinson’s Foundation.