Appendix linked to Parkinson’s
Some still dismiss the appendix as an organ that has outlived its usefulness. But new research suggests it may play an active – and detrimental – role in the development of Parkinson’s.
In a finding that extends the link between gut and brain health, scientists found that people who had their appendix removed were 20 per cent less likely to develop the neurodegenerative disorder than people who did not have appendectomies.
What’s more, among older patients in whom Parkinson’s was eventually diagnosed, those who’d had their appendix removed experienced their first symptoms 3.6 years later, on average, than people who retained the tiny organ.
The authors of the new study, published recently in the journal Science Translational Medicine, stressed that their findings do not make the case for appendectomies as a strategy to prevent Parkinson’s.
Scientists suspect that proteins – called alpha-synuclein – migrate to the brain and, in Parkinson’s, somehow get ‘‘misfolded" and contribute to the formation of clumps called Lewy bodies, which invade and damage a site in the brain that helps regulate movement.
This emerging picture of Parkinson’s has focused scientists on ways they might detect and treat it before it harms the brain.
Gastrointestinal symptoms such as chronic constipation are often evident in people years before they are diagnosed with Parkinson’s, which has fostered interest in the brain-gut connection.
But there are still many mysteries to unravel. Scientists must nail down the full cast of characters – including genes, environmental toxins and misfolded proteins – implicated in the condition.
The new findings suggest the
The removal of the appendix is a robust finding but it leaves much to be explained.
appendix should be a special place of interest in this hunt.
‘‘It’s a piece to the puzzle,’’ said Dr Rachel Dolhun, a neurologist and vice president for medical communications at the Michael J Fox Foundation, a major funder of Parkinson’s research.
Scientists first observed two decades ago that abnormal alpha-synuclein proteins were evident in the brains of people with Parkinson’s.
Suspicions have increasingly fallen on the appendix as a nursing ground for the potentially troublesome proteins. A thumb-like protuberance from the large intestine, the appendix is a common site of acute inflammation. Surgeons routinely remove it.
If alpha-synuclein is created there, or if the appendix spawns the misfolded proteins that are the hallmark of Parkinson’s, the presence or absence of an appendix should make a difference.
It was a hypothesis they could test, using meticulous medical records kept in Sweden. One database contained records for 1.6 million Swedes over many decades. Many had appendectomies and far fewer were diagnosed with Parkinson’s.
The analysis revealed that removing the appendix early in life was associated with a roughly 20 per cent reduced risk of developing Parkinson’s.
The effect was magnified in people who lived in rural areas. Environmental contaminants are known to drive up Parkinson’s risk. In that population, appendectomies were associated with a 25 per cent lower risk of Parkinson’s.
But the decline in Parkinson’s risk was apparent only when the appendix was removed early in life. Removal of the appendix after the condition process starts had no effect, they found.
This doesn’t mean the riddle of Parkinson’s, first described in 1817 by Dr James Parkinson, is close to being solved. Coincidentally, Parkinson was the first to describe acute appendicitis, in 1812.
‘‘There could be many origins of the condition,’’ said co-author Viviane Labrie, a neurogeneticist at the Van Andel Research Institute in Michigan. The removal of the appendix is a robust finding, she said, but it leaves much to be explained. – Los Angeles Times