A new paper provides compelling evidence that the herpes virus responsible for cold sores may also be linked to Alzheimer's disease. The findings show that antiviral drugs drastically reduce the risk of senile dementia in patients with severe herpes infections.
Frontiers in Aging Neuroscience raises the tantalizing prospect of a simple, effective preventive treatment for one of humanity's most debilitating and costliest neurological disorders.
Herpes viruses are notoriously persistent. They remain lifelong in our neurons and immune cells, reactivating and resurfacing in blisters when they are under stress or illness.
"HSV1 could account for 50% or more of Alzheimer's disease cases," says Professor Ruth Itzhaki, of Alzheimer's expert who has spent over
Itzhaki has been shown to cause more often in carriers of APOE-ε4 ̵
19659002] "Our theory is that APOE-ε4 carriers are more susceptible to HSV1-infected brain cells, which causes Alzheimer's disease."
Taiwan is one of the few countries in the world to collect the population data needed to test the HSV1-Alzheimer's theory. There, 99.9 percent of the population is enrolled in a National Health Insurance Research Database, which is extensively mined for information on microbial infections and disease.
In 2017-2018 three studies were published describing Taiwanese data on the development of senile dementia – of which Alzheimer's is the main cause – and the treatment of patients with HSV or varicella zoster virus (VZV, the chickenpox virus).
"The striking results include evidence that the risk of senile dementia is HSV1 who later develops dementia. "
Itzhaki's research provides a mechanistic link which supports it these epidemiological findings. Alzheimer's, including 'plaques' between neurons and 'tangles' inside of them.
"Viral DNA is located in plaques in postmortem brain tissue from Alzheimer's sufferers. Thus, HSV1-infected cell cultures and antiviral drugs can not prevent this, "Itzhaki says."
HSV1 (or VZV) infections, which are rare, "Itzhaki says. "HSV1 infection, including herpes labialis (cold sores) or mild genital herpes, but these are far less likely to be documented."
and define a causal link between HSV1 infection and Alzheimer's, Itzhaki is enthusiastic about the treatment prospects.
"Considering that over 150 publications strongly support HSV1 role in Alzheimer's well-tolerated – to treat Alzheimer's disease. "