A small organ that’s often considered useless might play a major role in whether or not a person develops Parkinson’s disease, according to a new study.
Scientists have long believed that Parkinson’s, an incurable neurodegenerative disease that affects more than 100,000 Canadians, may begin in the brain.
But a new study suggests that the tremor-inducing illness could have roots in an entirely different site much lower in the body: the appendix.
Researchers analyzed more than 1 million medical records and found that people who had their appendixes surgically removed had a lower risk of developing the brain disease.
“We found that removing the appendix was associated with a decreased risk of Parkinson’s disease, as high as a 20 per cent decrease,” Viviane Labrie, a Canadian neuroscientist and geneticist who led the research team out of Michigan’s Van Andel Research Institute, told CTV News.
“It also delayed the progression of the illness, so in patients who did go on to develop Parkinson’s disease, we had a 3.6-year delay in the onset of Parkinson’s.”
Researchers made the finding after combing through Sweden’s national health database, which keeps medical records of almost 1.7 million people going back to the mid-1960s.
One of the key findings, Labrie said, is that a clump protein considered the “hallmark pathology” of Parkinson’s was found in the appendixes of all individuals studied – no matter their age or health.
Researchers consider the appendix a “hub” containing the potentially dangerous protein, known as the alpha-synuclein.
“It’s present in everyone,” Labrie said. “And we think only in rare instances would it be able to accumulate excessively and escape the appendix and potentially enter the brain and cause Parkinson’s disease.”
Alpha-synuclein is known for its ability to move around the body. The protein can jump from neuron to neuron, and research has shown that it’s capable of travelling up the gastrointestinal tract and entering the brain.
Labrie likens the protein to a “seed” that can potentially spread once inside the brain.
Scientists have hypothesized a link between the gastrointestinal tract and Parkinson’s disease before, but the new study is the first to conduct a thorough investigation that examined human tissue samples.
And while researchers say they’ve found a source of the harmful proteins, there could be more sources of alpha-synucleins within the GI tract.
Because of this uncertainty, researchers say it’s far too soon to call your surgeon and schedule an appendectomy.
Instead, Labrie said more research is needed to find ways to control the rogue protein.
“I think a much better intervention is to dampen down the levels or excess clump protein associated with this illness,” Labrie said.
One of the more quizzical findings: people living in rural areas who underwent appendectomies appeared to benefit most from the reduced risk.
Researchers suggest that this link could point to the role of environmental factors, such as pesticides or herbicides, in the disease’s genesis.
Dr. Anthony Lane, a neurologist at Toronto Western Hospital, said more research is necessary before doctors establish the best way forward.
“We’ve got a very complicated situation that we still don’t fully understand. Our understanding is quite rudimentary. So this is one additional piece of information that has us interested and encourages further research.”
Parkinson’s disease is the second-most common neurodegenerative disorder, following Alzheimer’s disease.
According to Statistics Canada, the average age when Canadians first experience the disease is 64. About 5 per cent of people living in residential care facilities in Canada are diagnosed with the illness.
Individuals with Parkinson’s disease can experience a range of debilitating symptoms including tremors, slurred speech, restricted muscle movements and inhibited reflexes.
With a report by CTV News’ medical affairs specialist Avis Favaro and producer Elizabeth St. Philip