Researchers simulated the impact of head injuries on brain cells (Image: Getty)
Repeated head injuries could trigger disease by awakening a dormant virus in the brain, a study suggests.
Many people are infected with the virus that causes cold sores – herpes simplex virus type 1 (HSV-1) – during their lifetimes.
It can cause blisters and ulcers or simply remain dormant in the body. But previous research has also linked it to an increased risk of Alzheimer’s disease in certain people.
In the latest experiment, researchers led by Tufts University in Massachusetts, , grew stem cells in a lab which were reprogrammed to mimic brain cells.
The cells were infected with HSV-1 virus and then poked or hit to mimic repeated blows to the head. The impacts were found to reactivate the virus and led to an accumulation of proteins linked to brain damage.
Don’t miss…
Writing in the journal Science Signalling, the researchers said: “We thus propose that after repeated mechanical injuries to the brain, such as from direct blows to the head or jarring motions of the head, the resulting reactivation of HSV-1 in the brain may contribute to the development of [Alzheimer’s disease] and related diseases in some individuals.”
British experts cautioned that the research could not prove the link between the virus, head injuries and Alzheimer’s, but may open up new lines of progress.
Dr Julia Dudley, head of research strategy at Alzheimer’s Research UK, said: “The researchers used cell models for their experiments, and further investigation is needed to see whether these results apply to people.
“That said, studies like these highlight new treatment avenues, such as using medicines that target these viruses or reduce harmful inflammation in the brain.
“Understanding the first changes in Alzheimer’s disease could help provide the crucial first steps towards a cure.”
Don’t miss…
Professor Robert Howard, an expert in old age psychiatry at University College London, said: “The study is interesting and raises a potential mechanism for the observed association between infection with the cold sore virus, brain injuries and Alzheimer’s disease.
“However, as so often in science, it is very important to bear in mind that association does not mean causation. Much more research will be needed before this can be seriously considered a plausible mechanism for the development of dementia.
“Avoidance of brain injuries, such as those encountered in some contact sports, is already known to be an important way to prevent dementia and I’m unconvinced that this reflects anything more complicated than mechanical damage causing death of brain cells.”