Cold sore drug ‘could prevent Alzheimer’s due to herpes link’

A COMMON treatment for cold sores could help to prevent Alzheimer’s disease, it was claimed today.

Professor Ruth Itzhaki said the herpes antiviral drug acyclovir, also called Zovirax, could prevent dementia-causing plaques from forming in the brain. Her research “strongly implicated” the herpes simplex virus type 1 (HSV1) — which causes cold sores — in Alzheimer’s.

This may pave the way to preventing Alzheimer’s by vaccinating children against the virus, though there is no vaccine at present. Many experts are sceptical of her claims. Alzheimer’s Research UK said the study did not mean having cold sores increased dementia risk.

Manchester University’s Professor Itzhaki, in the journal Frontiers in Ageing Neuroscience, said “strong evidence” for HSV1 being a “major risk” forAlzheimer’s had emerged in three studies this year.

The most recent found 8,362 people aged 50 or older with herpes were 2.5 times at greater risk of developing senile dementia than the general population. Less than six per cent of the patients who received Zovirax or a similar drug developed dementia, compared to more than 28 per cent who did not get the drug.

Herpes infects most humans in infancy and can be reactivated by stress, causing cold sores. Professor Itzhaki said: “We propose that HSV1 enters the brain in the elderly as their immune system declines... [and] repeated activation causes damage, leading eventually to Alzheimer’s.”

John Hardy, professor of neuroscience at UCL, said: “None of the evidence she cites is, on its own, convincing, but there is evidence of links between inflammatory processes and Alzheimer’s.”