Over the years, people have suggested many different causes for MS. Here are some of the most popular theories that have been proved incorrect:
- Owning a dog or other small pet
Some years ago, canine distemper, a virus carried by dogs, was proposed as a cause of MS, but research has since ruled out household pets as the culprit.
There is no evidence that MS is triggered by a reaction to a specific environmental allergen. Since allergies are common in the general population, allergies can occur in a person with MS.
- Exposure to heavy metals
Although poisoning with heavy metals such as mercury, lead or manganese can damage the nervous system and produce symptoms such as tremor and weakness, both the process and the symptoms are different from what occurs in MS. There is no evidence that heavy metal exposure causes MS.
- Physical trauma
A 1999 report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology, based on a comprehensive study of the literature on the subject, concluded that "the evidence supports no association between physical trauma and either MS onset or MS exacerbation." Read their report in the journal Neurology or read more about trauma and MS.
No scientific evidence supports the claims on several Web sites that aspartame, an artificial sweetener used in many diet soft drinks and other foods, causes MS. For more information about aspartame, check out the following Web sites: