A new commentary by scientists at the Universities of Manchester and Edinburgh on a study by Taiwanese epidemiologists supports the viability of a potential way to reduce the risk of Alzheimer’s disease.
When the Taiwanese authors looked at subjects who suffered severe herpes infection and who were treated aggressively with antiviral drugs, the relative risk of dementia was reduced by a factor of 10.
“This article and two others by different research groups in Taiwan provide the first population evidence for a causal link between herpes virus infection and Alzheimer’s disease, a hugely important finding,” said Professor Ruth Itzhaki from the University of Manchester.
“These safe and easily available antivirals may have a strong part to play in combating the disease,” she said.
“It also raises the future possibility of preventing the disease by vaccination against the virus in infancy.
“Successful treatment by a specific drug, or successful vaccination against the putative microbe, are the only ways to prove that a microbe is the cause of a non-infectious human disease.”
Most Alzheimer’s disease researchers investigate its main characteristics – amyloid plaques and neurofibrillary tangles; however, despite the vast amount of research, the causes of their formation are unknown.
The herpes simplex virus type 1 (HSV1), which has been found to lead to an increased risk of developing Alzheimer’s, infects most humans in youth or later, and remains lifelong in the body in dormant form.
From time to time, the virus becomes activated and, in some people, it then causes visible damage in the form of cold sores.
The Taiwanese study identified 8362 subjects aged 50 or more during the period January to December 2000 who were newly diagnosed with severe HSV infection.
The study group was compared to a control group of 25,086 people with no evidence of HSV infection.
The authors then monitored the development of dementia in these individuals over a follow-up period of 10 years between 2001 and 2010.
The risk of developing dementia in the HSV group was increased by a factor of 2.542. But, when the authors compared those among the HSV cohort who were treated with antiviral therapy versus those who did not receive it, there was a dramatic tenfold reduction in the later incidence of dementia over 10 years.
Professor Richard Lathe from the University of Edinburgh said the findings were encouraging.
“Not only is the magnitude of the antiviral effect remarkable, but also the fact that – despite the relatively brief duration and the timing of treatment – in most patients severely affected by HSV1, it appeared to prevent the long-term damage in the brain that results in Alzheimer’s,” he said.
Do you suffer from cold sores? Are you worried about an increased risk of dementia as a result? Would you consider taking antiviral medication to reduce that risk?