Does herpes cause Alzheimer's?

What causes Alzheimer's disease? The answer could be right under our noses, says leading expert Professor Ruth Itzhaki. Her latest paper presents a lifetime of research evidence that the herpes virus responsible for cold sores can also cause Alzheimer's - and new data which show antiviral drugs drastically reduce risk of senile dementia in patients with severe herpes infections. The review in Frontiers in Ageing Neuroscience raises the tantalizing prospect of a simple, effective preventive treatment for one of humanity's costliest disorders.

The HSV1 theory of Alzheimer's disease






Proving the theory

Few countries collect the population data required to test this theory - for example, to find out whether antiviral treatments reduce dementia risk.


"The striking results include evidence that the risk of senile dementia is much greater in those who are infected with HSV, and that anti-herpes antiviral treatment causes a dramatic decrease in number of those subjects severely affected by HSV1 who later develop dementia."

Previous findings from Itzhaki's own research group provide a mechanistic link which supports these epidemiological findings. They found that HSV1 causes protein deposits characteristic of Alzheimer's: 'plaques' between neurons, and 'tangles' inside of them.


Towards a cure

"It should be stressed that the results of these Taiwanese studies apply only to severe HSV1 (or VZV) infections, which are rare," admits Itzhaki. "Ideally, we would study dementia rates amongst people who have suffered mild HSV1 infection, including herpes labialis (cold sores) or mild genital herpes, but these are far less likely to be documented."


"Considering that over 150 publications strongly support an HSV1 role in Alzheimer's, these Taiwan findings greatly justify usage of antiherpes antivirals - which are safe and well-tolerated - to treat Alzheimer's disease.

"They also incentivize development of an HSV1 vaccine, which would likely be the most effective treatment."

This echoes the growing use worldwide of human papillomavirus (HPV) vaccination to prevent cervical cancer - another virus-disease link which emerged in a similar process of research.