A recent study, reported on the BBC Web site, has linked the bacteria that cause stomach ulcers to Parkinson’s Disease.
To my mind, it’s not a very conclusive finding. The researchers, based in Louisiana, gave mice large doses of the bacteria Helicobacter pylori and the “middle-aged” mice went on to develop “Parkinson’s like symptoms”, while younger mice did not. The researchers have also identified a chemical route by which H. pylori can cause loss of neurons.
- The abstract for this study can be read here. It gives additional details on the methods used in the mouse experiments.
Now, humans are the only animals that get Parkinson’s – so any study using mice cannot be conclusive by itself. There are, of course, several causes in humans of “Parkinson’s like symptoms” that are not, actually, Parkinson’s Disease. In fact, the researchers themselves cite one such example; H. pylori is, apparently, able to generate a neurotoxic chemical “almost identical to one found in seeds from the cycad plant, which had been shown to trigger a Parkinson’s-like disease among people in Guam.”
I would also note that, as I understand it, current thinking is that there are likely to be several triggers that are suspected of causing Parkinson’s. Head trauma is one, inflammation another, and it is likely that some cases may be genetic. Environmental factors are also suspected, notably pesticides (one study based on farming communities in California’s central valley is particularly well known for promoting this link).
To mitigate my scepticism, it should be noted that a correlation between Parkinson’s and stomach ulcers has been observed in the past:
“Physicians have noted a correlation between stomach ulcers and Parkinson’s disease as far back as the 1960s, before it was even known that H. pylori was the cause of ulcers. More recently, a number of studies found that people with Parkinson’s disease were more likely to be infected with the bacterium, and that Parkinson’s patients who were treated and cured of infection showed slight improvement compared to controls that continued to deteriorate.”
However, Dr Kieran Breen, director of research at Parkinson’s UK, is quoted in the BBC article as saying that “no strong evidence that people who have H. pylori in their gut are actually more likely to develop Parkinson’s.” And, to be honest, I have a lot of faith in the people at Parkinson’s UK. They have a great deal of experience and knowledge on the topic.
Personally, I have never had a stomach ulcer. I have never experienced any notable head trauma. I do not believe that I have had a large exposure to pesticides. There is no history of Parkinson’s in my family. My health has, in general, always been good; I have certainly not had any extended periods of illness. The only factor I have come across so far that seems in any way relevant to my own case is the very tentative link that was made with hay fever.
As a Young Onset Parkie, I feel uncomfortable about the noted differences between the young and the “aged” mice and the way in which this is held up as being further evidence to support the link with Parkinson’s. Parkinson’s is not exclusive to older people, and careless reporting like this will only reinforce the public’s perception that it is a disease of old age.