The herpes virus could account for at least half of Alzheimer's cases, according to a new review of the findings of three recent studies examining links between Alzheimer's and herpes.
The new paper, published in the Frontiers in Ageing Neuroscience journal, also suggests that antiviral drugs may reduce the risk of senile dementia — which is mostly caused by Alzheimer's disease — among people who have severe cases of herpes. Herpes simplex virus 1 (HSV1) is the type of herpes that results in cold sores. HSV1 is a common virus, and the majority of people will have contracted it by the time they reach old age. However, the virus remains permanently in the body and cannot be decisively removed either by the body's natural defense mechanisms or by drugs.
The virus is inactive most of the time, but when a person has HSV1, they may find that flare-ups occur when they are stressed or sick, resulting in characteristic blisters. Medical News Today have reported on several studies this year alone that have provided evidence of a connection between Alzheimer's and herpes. In June, we looked at a study in which postmortem tests on brain tissue support a mechanistic link between Alzheimer's and the herpes viruses HHV-6A and HHV-7. And in July, we brought you news on a study that found the use of antiherpetic medication may dramatically reduce dementia risk.
Study author Professor Ruth Itzhaki, from the University of Manchester in the United Kingdom, found in previous studies that cold sores caused by HSV1 are more prevalent among people that carry a gene variant called APOE-e4, which may increase a person's risk of developing
Alzheimer's. "HSV1 could account for 50 percent or more of Alzheimer's disease cases," she states. Our theory is that in APOE-e4 carriers, reactivation is more frequent or more harmful in HSV1-infected brain cells, which as a result accumulate damage that culminates in development of Alzheimer's."
For this review, she looked at three recent studies on the relationship between Alzheimer's and herpes or chickenpox that analyzed population data from Taiwan, a country which enrolls almost all citizens in the National Health Insurance Research Database.
Because this database is so comprehensive in collecting health data from the Taiwanese population, it has become an important resource for researchers who are interested in examining the relationships between microbial infections and diseases. Itzhaki says that these studies provide "striking" evidence that people who have herpes viruses are at a much higher risk of developing senile dementia. Also, the results of these studies suggest that the use of antiviral medication may result in "a dramatic decrease" in dementia risk.
However, researchers need to conduct further studies to confirm that HSV1 causes
Alzheimer's. So far, these studies can only show that there is a relationship between the two conditions. Despite this, Itzhaki believes that the data so far supports the case of using antiviral drugs to deter Alzheimer's.
I’ve written several blogs on Alzheimer’s disease. To review them, just enter “Alzheimer’s” in the search box in the upper left hand corner of by blog page.
The prevalent theory on autoimmune disease and Alzheimer’s is that low grade infections in the body act as a triggering mechanism to the immune system. EBV (Epstein-Barr), CMV (cyclomegalovirus), Lyme disease and herpes have all shown to be potential triggers for these chronic diseases.
Environmental factors, specifically DDT and Round-up, have also been cited as toxins that facilitate these infections. In the case of Alzheimer’s disease, these toxins are known to uncouple copper from the nervous system, allowing the formation of amyloid plaque clusters found in the brain of Alzheimer’s victims.
However, I am not yet convinced that antiviral medication will reduce the incidence of these diseases.
More research is needed into the role of low-grade viral infections and chronic disease. Please hold off on preventative treatment with anti-viral medications.
Source: October 19, 2018 NIH