Movement difficulties

People with Parkinson's disease often suffered from constipation earlier in life

The Economist, 23 August 2001
ALISON MOTLUK

FEELING a little stopped up? Can't get relief? Research in Hawaii suggests that constipation, especially when it defies laxatives, could be an early symptom of Parkinson's disease. The more constipated you are, the more likely you are to go on to develop the neurological problems that cause the muscular tremors which characterise Parkinson's.

The research, published recently in Neurology by Robert Abbott of the Pacific Health Research Institute in Honolulu and his colleagues, examined data on 6,790 Japanese-American men. These men were participants in a long-term health study as one part of which, from 1971 to 1974, they reported the frequency of their bowel movements. Over the subsequent 24 years, 96 of them went on to develop Parkinson's disease.

That patients with Parkinson's often suffer constipation is well known—James Parkinson himself noted it when he characterised the syndrome in 1817. But Dr Abbott wanted to know if the men who eventually got the disease were blocked in the bathroom long before other symptoms started to show up.

Intriguingly, they were. The fewer their daily bowel movements during the early 1970s, the greater their risk of developing the disease. Those who reported less than one movement a day were 2.7 times more likely to develop Parkinson's than those who had one a day—and 4.5 times more likely to do so than men who boasted more than two each day. Also significant is the finding that men who used laxatives but got little relief from them were the most likely of all to develop Parkinson's.

All this suggests to Dr Abbott that Parkinson's may not be simply a disease of the brain, as is now believed. It may, rather, be something more systemic. The pathology of constipation and the pathology of Parkinson's disease are similar, he says. In particular, Parkinson's is associated with a lack in the brain of a messenger molecule called dopamine. Nerve cells in the colons of constipated people lack dopamine, too. Even more intriguingly, nerve cells in the colons of Parkinson's sufferers who are constipated contain structural abnormalities known as Lewy bodies, which are a hallmark of the affected brain tissue in people with Parkinson's. In other words, the first sign of the movement disorder associated with Parkinson's may be in the gut, not the brain.