Scientists link digestive problems to Parkinson’s disease

New research suggests that digestive problems may be a warning sign of Parkinson’s disease. Scientists have concluded that a higher risk of developing diseases is observed in patients with bowel problems.

Digestive problems, such as constipation or difficulty swallowing, can double your chance of developing Parkinson’s disease, according to new research. The origin of Alzheimer’s disease, strokes and brain aneurysms has also been linked to the gastrointestinal tract. Although there is evidence that Parkinson’s disease can also start in the gut, little research has been done on its association with specific digestive disorders.

Now, a study has established that four bowel conditions may be an early warning sign of Parkinson’s disease. The authors conclude that this is “the first significant observational evidence” that a clinical diagnosis of bowel problems “can specifically predict the development of Parkinson’s disease.”

The researchers compared the medical records of 24,624 people in the US with Parkinson’s disease, 19,046 people with Alzheimer’s disease, and 23,942 people with cerebrovascular disease.

Patients with Parkinson’s disease were matched with patients from other groups by age, gender, race and ethnicity, and duration of diagnosis to compare the incidence of gastrointestinal disease six years prior to diagnosis.

The scientists also compared the medical records of all study participants who were diagnosed with any of the 18 bowel diseases with those who had not had that particular disease for five years to see how many of them developed Parkinson’s disease or other neurological disorders.

Both comparisons revealed a higher risk of being diagnosed with Parkinson’s disease in patients with bowel problems. Patients with constipation, difficulty swallowing (dysphagia), and gastroparesis, in which food takes longer to pass from the stomach to the small intestine, were more than twice as likely to develop Parkinson’s disease five years before diagnosis.

Certain gastrointestinal symptoms, including functional dyspepsia (burning or fullness of the stomach with no apparent cause), irritable bowel syndrome (IBS) with diarrhea, and diarrhea plus fecal incontinence, have been found to be more common in patients who also develop Parkinson’s disease. But they were also more common before the onset of Alzheimer’s disease, aneurysms, or strokes.

However, the study found that other bowel problems, such as inflammatory bowel disease, do not increase the likelihood of developing Parkinson’s disease.

The authors of the study calculated that patients who had their appendix removed were less likely to develop Parkinson’s disease. They added that the findings “require attention” to bowel problems in patients at higher risk of Parkinson’s disease and require further study of the links between gastrointestinal disease and Alzheimer’s disease, strokes and aneurysms.

Parkinson’s UK estimates that by 2030 there will be around 172,000 people with the condition in the UK alone. And according to the World Health Organization, there are 8.5 million people in the world suffering from this disease.

Responding to the findings, Claire Bale, deputy director of research at Parkinson’s UK, said the findings “given extra weight” to the growing evidence that bowel problems “may be an early sign of Parkinson’s disease.”

Claire Bale said: “Understanding how and why gut problems appear in the early stages of Parkinson’s disease could open up opportunities for early detection and gut-targeted treatment approaches to improve symptoms and even slow or halt disease progression.”

Kim Barrett, associate dean of science at UC Davis, said it may be important for clinicians to “take into account” these gut conditions when evaluating patients at risk for Parkinson’s disease, “even before neurological symptoms appear,” but urged caution . She said: “The findings are purely correlational and it remains possible that both gastrointestinal disease and Parkinson’s disease are independently associated with an as-yet unknown third risk factor.”