Can Germs Cause Alzheimer's Disease?

A debate is being waged among scientists as to whether Alzheimer's may have a microbial cause, reports the Philadelphia Inquirer . A recent Mount Sinai-Arizona State University study found the brains of people with Alzheimer's contained more of two types of herpes viruses — HHV-6 and HHV-7 — than the brains of people without dementia. In addition, Harvard University researchers discovered that amyloid clumps are part of the body's innate immune system in lab studies and mice. Earlier studies by the Philadelphia College of Osteopathic Medicine's Brian Balin determined the presence of chlamydia disproportionately in brains of persons with Alzheimer's, and also implicated the herpes virus that causes cold sores. Judith Miklossy with the Prevention Alzheimer International Foundation and International Alzheimer Research Center in Switzerland says the pathology in brains of people with late-stage syphilis is virtually indistinguishable from that in Alzheimer's. "It is clear that there are more and more data being accumulated that point to a connection of some kind between viral sequences and Alzheimer's in the brain," admits National Institute on Aging Director Richard Hodes. However, he stresses that a correlation between the presence of microbes in the brain and Alzheimer's pathology does not prove one leads to the other.