It could still be years before the causal connection between the memory loss diseases and herpes is proven. However, the idea that it’s a possible reason could increase the chances of creating a preventive treatment.
Taiwanese researchers recently published two papers that concluded serious herpes infections raised a person’s chance of being diagnosed with dementia. Other Taiwanese researchers carried out another study where the risk was similar with a different strain of herpes. In the last study, it showed that dementia developed was prevented in most patients using anti-herpes medications.
Britain researchers concluded from these studies that herpes might not just raise a person’s chance of developing dementia but the evidence suggests it can actually cause the disease.
University of Manchester in England Neuroscience Professor Ruth Itzhaki said while it’s not definitive proof, it seems to be very likely the case.
And, it’s not just the studies in Taiwan that are turning heads.
The Icahn School of Medicine at New York’s Mount Sinai as well as Arizona State University looked at the brains of people who died with Alzheimer’s disease. According to their findings, there were elevated levels of herpes viruses in their brain compared to people who didn’t have Alzheimer’s.
Still, it’s all speculation.
Alzheimer’s Association Director of Scientific Programs and Outreach Keith Fargo said the science is still not conclusive enough to say, without a doubt, “Yes, herpes is a cause for dementia-related diseases.”
More research is needed to prove that an anti-herpes vaccine or treatment would help in the decline of dementia diagnosis. And, proving the link and tracking the people who got the vaccine would be difficult and possibly impossible.
However, according to Fargo, there are two possible studies in the U.S. looking to do just that.
Researchers are looking for people who they’ve assessed as being at-risk for having herpes re-appear in their brain and treat them with antivirals before they were diagnosed with having dementia.
There are multiple strains of the herpes virus, and most studies focus on the HSV 1 and HSV 2 strains. However, the HHV 6A, 6B and 7 are being considered as a possibility for dementia.
Fargo said most people have at least one herpes strain in their body.
The virus is usually contracted when a person is a child but can rear its ugly head as they get older in another way. For instance, the chicken pox virus stays dormant until later in life when it causes some people to suffer from shingles. Fargo said this is what the herpes virus is like as well.
The theory goes that the herpes virus could reawaken and inflict its damage on the brain, potentially causing dementia and other cognitive-declining diseases.
According to Itzhaki, herpes is not the only thing that causes dementia, but she’s been looking at the link between the virus and the disease for quite some time.
She said she, along with some colleagues, discovered amyloid plaques in Alzheimer’s patients’ brain that has herpes DNA, but it wasn’t until now that the theory of it causing dementia caught on. Itzhaki said it was a battle for people to recognize the possibility but it seems more people are in agreement to the idea.
Should more research into the possibility reveal that herpes causes dementia, it could mean a person could take a drug that would lower the risk of developing the disease later in life.
According to Itzhaki, if the antiviral drugs given during the Taiwanese study kept the brain safe from the virus, it could work with people who have a mild case of herpes.
Written by Mark Riegel, MD
Here’s what we've been up to recently.