Could Cold Sores Lead to Alzheimers?
Last Updated on Tuesday, 09 December 2008 17:00
The research that was published in the Journal of Pathology showed a frighteningly high percentage of Alzheimer’s patients had contracted the herpes simplex virus (HSV) type 1, frequently associated with cold sores.
AD is the most common form of dementia and leads to a loss of mental capacity, in particular the loss of memory. Alzheimer’s is caused by clumps of plaques which form around the brain cells and slowly erode them; destroying connections which allow the chemical transfer of messages in the brain.
Whilst scientists have known for a long time that AD is caused by plaque in the brain, this new research revealed the type of plaque. The research found DNA evidence that 90 per cent of plaques in the brains of Alzheimer’s patients were infected with HSV type 1.
The research was led by Professor Ruth Itzhaki, an expert biophysicist who has worked in Radiotherapeutics, Optometry and Neuroscience. Professor Itzhaki has specialised in DNA genetics but recently turned her attentions to viral infections in DNA, in particular to Alzheimer’s disease.
In an extract from the research paper, the research revealed: “We discovered a striking localization of herpes simplex virus type 1 DNA within plaques”.
The research showed that in a normal brain, 80 per cent of plaques were infected with the virus, but the Alzheimer’s patients had a full 10 per cent extra than a normal brain with 90 per cent containing the cold sore herpes.
The paper went on to say “Obviously, association does not prove causality. However, alternative explanations for viral presence in plaques are very unlikely.” The other possible explanations of how the virus could manifest were disregarded in the paper as “doubtful” and “very improbable”.
The findings of the research indicated “the likely cascade of events leading from HSV1 infection” and suggested that, “the virus enters the brain in the elderly as their immune systems decline and then establishes a latent infection, from which it is repeatedly reactivated by events”.
The weaker immune systems of the frail and elderly allow the herpes virus to bypass the body’s defences. Once the virus takes hold, it is incubated through periods of stress and brain inflammation.
Professor Itzhaki concluded that, “the present data strongly implicate HSV1 in sporadic AD as an actual cause of, and a pathway for, amyloid plaque formation, and hence a likely major cause of the disease.” On the basis of this research, the biophysicists at the University of Manchester hope to test antiviral drugs that are currently used to treat cold sores. The hope is that the drugs which help to block the herpes virus might provide the first step to a cure for Alzheimer’s. Over the counter treatments like Zovirax may hold the key to beating AD.
Rebecca Wood from the Alzheimer’s Research Trust told the BBC: “This could lead to new treatments for Alzheimer’s based on existing antiviral agents.” She warned though that, “much more research is needed if we are to offer hope to the 700,000 people in the UK who live with Alzheimer’s and related dementias.”
