Could cold sores and shingles lead to Alzheimer’s disease?
New research from Tufts and Oxford universities adds to growing evidence that they could – and how.
And the implications are both good and bad. Good, because it means vaccines could help prevent Alzheimer’s disease, for which there are very few drugs and no known cure. Bad, because somewhere between 50% and 80% of the population has herpes simplex, the virus that causes cold sores.
The problem is that herpes simplex is mostly dormant in the body and very rarely reactivates.
Cell culture studies have revealed that adding the shingles virus, varicella zoster, or VZV, to cells containing herpes simplex 1 or HSV-1 “causes reactivation of HSV-1 and AD which result”. [Alzheimer’s or dementia]– like changes,” including 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 likely through inflammation, the researchers report.
They concluded that shingles alone, which has previously been implicated in the development of Alzheimer’s disease, probably does not cause the disease. But it is possible 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 the major role of HSV-1 in AD.”
The field of Alzheimer’s disease research is littered with false starts and dashed hopes. He was also hit with other bad news recently: investigative reports of fraud in a key 2006 study. No one should set their hopes too high.
In contrast, when it comes to Alzheimer’s, we are currently faced with a very simple aspect of game theory. So far, nothing is working. We don’t know how to treat the disease, stop it or reverse it. Breakthrough drugs are currently very rare.
Yet around 6.5 million Americans already have this dreadful disease, and that number will steadily increase as the number of old people and “old old women” grows. Alzheimer’s disease is a disease that not only kills, but kills slowly and cripplingly, maximizes the pain of death for a patient’s family and friends, and absorbs vast amounts of valuable nursing and medical care that cannot then be applied elsewhere.
So anything that could be good news is better than what we have.
If someone actually developed a vaccine for herpes simplex, it would also help in the fight against Alzheimer’s disease.
The shingles and cold sores study adds to growing evidence that Alzheimer’s disease can be caused or triggered by regular infections (likely by inflammation that reactivates dormant herpes simplex). This is an area of increasing interest to researchers. Researchers report that vaccination against shingles reduces the risk of developing Alzheimer’s disease. Likewise, research has suggested doing vaccinations against influenza, diphtheria, tetanus, and other illnesses.
With this disease, it’s two inches forward, one inch back. But we’ll take what we can and keep hope alive.