New research highlights a link between the removal of the appendix and a reduced risk of developing Parkinson's.
Researchers at the Van Andel Research Institute in America have discovered that removing the appendix in early life reduces the risk of developing Parkinson's by 19 to 25 percent.
The study, which analysed data from more than 1.6million people, also investigated how the appendix may be contributing to the condition and identified the presence of clumps of alpha-synuclein protein in the appendixes of healthy people.
Where does Parkinson's start?
Parkinson's is caused by the loss of dopamine-producing brain cells. However, recent research has suggested that the condition may not always start in the brain.
Researchers have become increasingly interested in how sticky clumps of a protein called alpha-synuclein, which is believed to play a role in the progression of Parkinson's, could form in other areas of the body and travel via nerve pathways into the brain.
These clumps of toxic alpha-synuclein, called Lewy bodies, are present in the brains of every person with Parkinson's. But there is evidence that they may originate in other areas of the body and travel to the brain.
Lewy bodies have previously been found in the gut and vagus nerve - the nerve which connects the gut to the brain. And research suggests that a severing this nerve, in a procedure known as a vagotomy, may prevent them spreading into the brain, reducing the risk of Parkinson's.
Now, these results, published in the scientific journal Science Translational Medicine, show clumps of alpha-synuclein can also be present in the appendix and that appendectomy may also reduce risk.
Commenting on the study, Claire Bale, Head of Research at Parkinson's UK, said:
"The finding that removing the appendix early in life can reduce risk of Parkinson's suggests that it may play a contributing role in the loss of brain cells. This builds on previous research indicating that, for some, Parkinson's starts in the gut.
"There is much still to learn about how surgical approaches, such as removing the appendix, may stop the progression of toxic proteins that cause Parkinson's. However, these approaches are unlikely to eliminate the condition, as Parkinson's may also start in other areas of the body or brain.
"In most cases, the causes of Parkinson's are a mystery. But understanding how the condition starts and progresses is the first step to stopping it. If we can couple this understanding with tests that detect the earliest changes and treatments that can stop it progressing, we will have a real pathway to preventing Parkinson's."