Herpes exists in two common forms. Most people who are exposed to HSV-1 do not develop Alzheimer's. LaFerla explains this apparent paradox by citing recent studies showing that people genetically disposed to Alzheimer's are more likely to develop the disease if they are exposed to herpes. Herpes is one of a growing number of factors believed to contribute to Alzheimer's, a poorly understood, incurable form of dementia that primarily strikes the elderly and causes severe memory loss. In about 10 percent of cases there is a family history of the disease.
Researchers believe that the majority of the cases involve multiple factors.
While genetic predisposition has been well established, other potential risk factors include stress, prior head injury and an abnormal concentration of metals in the brain, including zinc, copper and lead. The study was supported by the National Institute on Aging, the Alzheimer's Association, and the State of California. It appears in the May 16 issue of Biochemistry.