Could cold sores plus shingles lead to Alzheimer’s? New research from Tufts and Oxford universities adds to the growing evidence that they might — and how. And the implications are both good and bad. Good, because it means vaccines could help prevent Alzheimer’s, for which there is very little medication and no known cure. Bad, because somewhere between 50% and 80% of the population has the herpes simplex, the virus that causes cold sores.
The issue is that herpes simplex mostly lies dormant in the body and very rarely reactivates. Studies in cell cultures found that adding the shingles virus, Varicella zoster, or VZV, to cells that contained herpes simplex 1 or HSV-1 “causes reactivation of HSV-1 and consequent AD [Alzheimer’s or dementia]–like changes,” including the beta-amyloid protein and p-tau tangles widely associated with the disease, write Dana Cairns and David Kaplan of Tufts and Ruth Itzhaki of Oxford. The method for reactivating herpes simplex was probably through inflammation, the researchers report. They concluded that shingles on its own, which has previously been implicated in the development of Alzheimer’s, likely does not cause the disease. But it can if a person already has herpes simplex. The researchers report that “over four hundred publications, using a variety of approaches, have provided further support for a major role f …