Dementia is linked to the cold sore virus
ALZHEIMER’S disease may be caused by the virus that triggers cold sores, researchers say.
If proved, the discovery could open the door to preventing the devastating neurological condition with just a jab or anti-viral medication.
Professor Ruth Itzhaki, of the University of Manchester, said a Taiwan study found anti-viral drugs drastically reduced the risk of dementia in patients with severe herpes infections.
It follows a lifetime of evidence that the virus, best known for its role in cold sores, fuels rogue amyloid beta proteins that destroy neurons.
Prof Itzhaki’s review, published in Frontiers in Ageing Neuroscience, raises the tantalising prospect of a simple preventive treatment for one of humanity’s most costly and cruel disorders.
Strain
Herpes viruses remain for life in our neurons and immune cells, reactivating and resurfacing in characteristic blisters when we are run down.
Most people are infected by the cold sore virus HSV1 (Herpes Simplex Virus 1) by the time they reach old age. It could be behind more than half of Alzheimer’s cases.
It is a different strain from the HSV2 virus that causes genital sores.
Prof Itzhaki, who has spent more than 25 years investigating the potential link, said: “HSV1 could account for 50 per cent or more of Alzheimer’s cases.”
Her previous work has shown cold sores occur more frequently in carriers of a gene mutation called APOE-e4 that increases the risk of Alzheimer’s.
She said: “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.”