Cutting-edge research suggests that a virus that infects a million Americans each year could increase the risk of dementia.
Stanford researchers found that shingles, a virus that causes a painful rash, could increase the risk of developing Alzheimer’s, such as People who received a vaccine were 20 percent less likely to develop the disorder years later.
This emerging field of research, linking the viruses that cause chickenpox, herpes and shingles to dementia, could be the key to breakthroughs in the mystery of Alzheimer’s, experts say.
Shingles is a viral infection caused by the same virus responsible for chickenpox. Victims develop blistering rashes that are painful and may be itchy.
Researchers have recently begun to investigate the link between viruses, such as varciella-zoster, which causes shingles, and neurodegenerative diseases. They are also looking at the virus that causes herpes, which is in the same family as varciella-zoster.
Shingles is caused by the same virus that causes chickenpox. After you get chickenpox, the virus, called varicella zoster, hides in the nervous system for life.
Randomly, as a person ages, the virus can reactivate and travel along the nervous system to the skin. according to the mayo clinic. Doctors aren’t sure what causes the virus to reactivate, but it tends to occur in people as they get older or sicker, suggesting it could have to do with a weakened immune system.
About a million people in the US get shingles each year, According to the Centers for Disease Control and Prevention.
At the same time, 500,000 Americans are diagnosed with Alzheimer’s every year. Despite how common the disease is, research into its cause has made little progress in recent decades.
Dr. Geldsetzer’s study, which represents a new theory for studying the disease, has not yet been reviewed by other scientists.
Still, it is available online through National Institute of Health since May 2023, and widely approved by other scientists in public.
The study analyzed 300,000 medical records of people born in Wales between 1925 and 1942 and tracked them over time, looking for their shingles vaccination, their diagnosis and their diagnosis of dementia.
In Wales, they designed shingles vaccination guidelines to have an age limit, based on data showing that vaccination was not effective in people over 80 years of age.
So the researchers had two groups to study: those born before 1933 who did not get vaccinated and those born after 1933 who did.
The groups were otherwise similar in age, preexisting conditions, and other health history.
They found that vaccination reduced the risk of developing dementia by 20 percent in the seven years after the injection.
‘We are seeing a causal effect. And it is specific to dementia. It’s clear that something is going on here. Pascal Geldsetzer, epidemiologist at Stanford University said STAT.
To make sure what they were seeing wasn’t specific to Wales alone, Dr Geldsetzer and his team ran similar analyzes in the UK and Australia, and found the same trend.
At the same time, researchers at the University of Oxford were conducting studies that added to the theory linking shingles to Alzheimer’s.
A study from 2024 published in the journal Nature analyzed the health records of 200,000 Americans and saw how they fared after receiving a form of shingles vaccine approved in 2017 called Shingrix.
A 2024 study showed that the Shingrix vaccine was linked to a “significantly” lower risk of dementia compared to Zostavax and shots for other diseases. This adds weight to other emerging research suggesting a link between shingles and dementia.
The vaccine reduced the risk of dementia by 17 percent over the six years after it was administered compared to older shingles vaccines that were less effective.
Paul Harrison, lead author and professor of psychiatry at the University of Oxford, told STAT: “I have always believed in vaccines, but the Covid vaccine reinforced to me that vaccination can have long-term benefits beyond simply stopping them in the short term. “. effects.”
Because the link between shingles and dementia is still so new, research has yet to explain how shingles may be causing some cases of the disease.
They think it may have to do with the length of time the virus hides in the nervous system after getting chickenpox.
Although the virus may seem harmless, Netherlands research suggests that your immune system is actively working to keep it in check while it remains in the body.
When you get older, sick, or the immune system is busy, this gives the virus a chance to attack other parts of the body.
This includes blood vessels, which neurologists at the University of Alabama has discovered that it can cause alterations in blood flow to the brain.
Reducing or cutting off blood flow to the brain for a prolonged period can put stress on the brain’s delicate cells, causing damage or death that could accumulate over time, contributing to an increased risk of dementia.
Whatever the cause of viral dementia, scientists like Dr. Maria Nagel, a neurovirologist at the University of Colorado who studies shingles, are excited that researchers are investigating it.
For a long time, most Alzheimer’s research and funding focused on a single theory.
Therefore, studying the link between neurodegeneration and viruses is a new opportunity, bringing new scientific minds to the puzzle that is Alzheimer’s.
Thinking about all the new people who have joined Alzheimer’s research in recent years, Dr. Nagel told STAT: “I really believe that in the next 10 years we will see great advances in finding new mechanisms and new ways to try to slow things down.