That is the tantalizing promise of a body of scientific research that points to microbes, including the ubiquitous herpes virus, as a possible cause of the disease.
The link between microbes and Alzheimer’s could pave the way for eventual treatments or a cure, something that continues to elude the medical world at a time when there is growing concern about skyrocketing rates of the disease.
Some of the leading researchers into the connection between infections and Alzheimer’s, known as the pathogen theory, were in San Francisco at the World Congress of Gerontology and Geriatrics in late July — the largest gathering yet of scientists in the aging field — to talk about their work.
Those studying the microbe-Alzheimer’s connection have long fought skepticism. Their work bumps against the dominant theory that Alzheimer’s disease is caused by the accumulation of plaque-forming beta-amyloid and tangles in the brain.
Researchers studying the microbe link believe those are downstream effects, either caused by infection, or the body’s immune response, and not the disease’s root cause.
Researchers took a dramatic step last year in an effort to get more support for their work. Thirty-one Alzheimer’s researchers from around the world made a plea for more focus on the microbe-Alzheimer’s connection. Their editorial in the Journal of Alzheimer’s Disease urged the science world, in a controversial editorial, to change its focus when it comes to the disease. After decades of failed attempts to treat and prevent the disease, they wrote, it is time to reassess the evidence that Alzheimer’s could be connected to microbes.
Neurologist Brian Balin, of the Philadelphia College of Osteopathic Medicine, who coauthored the editorial, said he believes that shift in thinking about possible causes is happening.
“We are closing in on what could actually cause the problem. The public should embrace that and feel that we can start to do something about it,” he said.
That could mean vaccines and also better diagnostics, which could lead to earlier treatment.
Prevailing Theory Remains Unproved
So far, the prevailing theory that plaque causes Alzheimer’s has not led to promise of either a cure or effective treatment.
“Alzheimer’s is ripe for a breakthrough, which I will predict is going to come in (this area of research), said Annelise Barron, a professor of bioengineering at Stanford University.
Still, scientists researching the links between microbes and the disease have long been outsiders in the world of Alzheimer’s research.
They compare themselves to Barry Marshall, the Australian physician who won a Nobel Prize for his discovery that bacteria cause most peptic ulcers, a theory he proved by experimenting on himself.
His finding — which ran counter to the prevailing view of the time that gastric disorders had a physiological basis, rather than being infectious diseases — was met with extreme skepticism, even hostility.
The Royal Society wrote that his work — which also paved the way for a breakthrough in stomach cancer — “produced one of the most radical and important changes in medical perception in the last 50 years.”
Alzheimer’s researchers working on the pathogen theory are hoping for the same kind of change.
“The World Health Organization has declared Alzheimer’s disease a priority,” said Swiss researcher Judith Miklossy, who studies the link between bacteria and Alzheimer’s disease. “If we can find the link, we can help a lot of people. This is the reason more of us are trying to do something.”
Prevention
The conference on aging also heard from researchers looking at ways to prevent dementia. Among factors associated with a higher risk of dementia are poor sleep quality, depression, social isolation, lack of education and head injury, the conference heard.
Dan Blazer, professor of psychiatry emeritus at Duke University, noted there is no good evidence that vitamins, supplements or even cardiovascular drugs reduce a person’s risk of dementia. Nor is there conclusive evidence about the benefit of brain games.
“We are still looking for a magic bullet, but we have not found it,” Blazer said.
Elizabeth Payne wrote this article for the Ottawa Citizen with the support of a journalism fellowship from New America Media, The Gerontological Society of America and the Silver Century Foundation.
