Will the Herpes Virus Give You Alzheimer's?
An editorial by dementia experts has sparked concern, but fears may not be justified
An alarming editorial in London's Telegraph newspaper in March said a team of 31 dementia experts have warned that microbes — including the viruses that cause cold sores and chlamydia — could cause Alzheimer's disease.
"We are saying there is incontrovertible evidence that Alzheimer's disease has a dormant microbial component," Professor Douglas Kell of the University of Manchester's School of Chemistry was quoted as saying. "We can't keep ignoring all of the evidence."
Scientists have been trying to find a treatment for the build-up of plaques in the brain that muck up the communication among neurons, leading to memory loss. The editorial in the Journal of Alzheimer's Disease suggested that a viral or bacterial infection triggers that build-up — and that antimicrobial drugs targeting those infections might stop dementia.
The writers called for new research in the area.
A Link Ignored?
"We write to express our concern that one particular aspect of the disease has been neglected, even though treatment based on it might slow or arrest Alzheimer's disease progression," the editorial said. "We refer to the many studies, mainly on humans, implicating specific microbes in the elderly brain, notably herpes simplex virus type 1, chlamydia pneumoniae and several types of spirochatete."
Herpes simplex virus type 1 is the kind usually associated with cold sores on the lips. Type 2 is the sexually transmitted variety, though oral sex can also transmit type 1.
Following the Telegraph story, The Washington Post urged readers to "calm down."
"The editorial — not a new study, but essentially an open letter to the medical community based on previous (inconclusive) research — was covered in fairly alarmist fashion by the Telegraph. Many outlets, including TIME and several men's websites, followed suit," the Post wrote.
But it pointed out that the Telegraph itself included this quote farther down in the story:
"This is a minority view in Alzheimer research," John Hardy, a professor of neuroscience at University College London. "There had been no convincing proof of infections causing Alzheimer disease. We need always to keep an open mind but this editorial does not reflect what most researchers think about Alzheimer disease."
Not Proof, Newspaper Says
Rather, the Post said, "It's all correlative. That means that a handful of studies have shown that older folks with active HSV infections (the virus lies dormant most of the time) are more likely to be diagnosed with Alzheimer's than those without. But no one has shown why this would happen, or given any evidence that it's the HSV causing the Alzheimer's.
"For all we know, the correlative relationship is pure coincidence — some estimate that 80 percent of the U.S. population has HSV-1, and that's a big chunk. There could be other, as-yet-uncovered risk factors that these individuals also had in common."
Read the Telegraph and the Washington Post articles here:
Alzheimer's disease could be caused by herpes virus, warn experts
Calm down: Herpes probably isn't going to give you Alzheimer's
