Gut Damage May Boost Risk of Parkinson's

In the puzzle that is Parkinson's disease, there are dueling camps: "brain-first" versus "gut-first." The former proposes that Parkinson's starts in the brain with the loss of dopamine-producing neurons ultimately linked to muscle stiffness and tremors. The latter suggests the problem begins with abnormal proteins in the nerves of the gastrointestinal tract, which work up to the brain. It's partly based on patients reporting gastrointestinal symptoms, including constipation, years before neurological symptoms appear and the fact that constipation is a major risk factor for Parkinson's. Now, a new study indicates upper gastrointestinal conditions are a risk factor, too, per the Washington Post.

Harvard Medical School professor Subhash Kulkarni and colleagues found that people who had upper gastrointestinal conditions—for example, a stomach ulcer or damage to the lining of the esophagus or small intestine—were much more likely than others to develop Parkinson's. They analyzed data on 9,350 mostly middle-aged patients with no history of the disease who had an upper endoscopy with biopsy between 2000 and 2005. Those who suffered damage to the mucous lining of the gastrointestinal tract had a 76% greater risk of developing Parkinson's during the follow-up period (15 years on average).

This backs the theory that damage to the gut lining could trigger an avalanche of misfolded alpha-synuclein proteins that eventually spread from the gastrointestinal tract to the brain via the vagus nerve, the Post reports. For those with upper gastrointestinal conditions, there's "cause to worry but there's no cause to panic," Kulkarni tells KCBS Radio, calling for timely treatment as well as heightened monitoring of patients. The good news is that if researchers can show mucosal damage is an early warning sign of Parkinson's, vigilant doctors could potentially deliver neuroprotective treatments before motor symptoms appear. The average time between a patient's reporting of mucosal damage and a Parkinson's diagnosis was more than 14 years. (More Parkinson's disease stories.)