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 for HSV-1 in AD.”
The field of Alzheimer’s research is literate with false starts and dashed hopes. It has also recently been hit by more bad news: reports of a fraud investigation into a key 2006 study. Nobody should get their hopes up too high.
On the other hand, when it comes to Alzheimer’s, we are currently dealing with a very simple aspect of game theory. Right now, nothing works. We don’t know how to treat the disease, nor stop it or reverse it. Breakthrough drugs are currently very rare.
Yet already about 6.5 million Americans have this terrible disease, and the number will rise steadily as the number of old, and “old old,” goes up. Alzheimer’s is a disease that is not only fatal but kills slowly and in a crippling manner, maximizes the pain of death to a patient’s family and friends, and soaks up vast amounts of precious nursing and medical attention that then cannot be applied elsewhere.
So anything that might be good news is better than what we have.
If someone actually developed a vaccine for herpes simplexit would also help in the fight against Alzheimer’s.
The study on shingles and cold sores adds to growing evidence that Alzheimer’s may be caused or triggered by regular infections (possibly through inflammation that reactivates dormant herpes simplex). This is an area of growing interest in researchers. The researchers report that vaccination against shingles reduces the risk of developing Alzheimer’s. So, too, research has suggested, do vaccinations against flu, diphtheria, tetanus and other diseases.
With this disease it’s two inches forward, one inch back. But we’ll take what we can get, and keep hoping.