Share on PinterestRecent research emphasizes the potential role of viral infections and over-the-counter medication in dementia risk. Design by MNT; Photography by alvaro gonzalez/Getty Images, Guido Mieth/Getty Images, Tatjana Zlatkovic/Stocksy & Catherine Falls Commercial/Getty Images.
- Researchers have identified various potential risk factors and causes for cognitive decline, which can sometimes be a sign of dementia. One of these is brain inflammation.
- Some recent studies have looked both at what might trigger this inflammation and at potential avenues to treat or prevent cognitive decline.
- An increasing amount of research has also been linking Alzheimer’s disease to herpes viruses, particularly the one that causes cold sores.
- Other studies have linked the use of vaccines, antibiotics, and even over-the-counter anti-inflammatories, such as ibuprofen and aspirin, to a lower risk of dementia.
While the causes behind cognitive decline and, more importantly, dementia, remain uncertain, researchers have taken huge leaps toward identifying likely contributing factors.
One of these key factors appears to be inflammation and, in particular, neuroinflammation, or brain inflammation, which has been linked with cognitive impairment and the development of dementia.
A question that arises, then, is what may trigger some of these instances of inflammation that end up affecting brain health. An increasing amount of evidence is now linking viral infectionsTrusted Source with the advent of neurodegenerative diseases, including Parkinson’s disease, multiple sclerosis (MS), and also Alzheimer’s disease, the most common form of dementia.
Over the past few months, studies have suggested that one specific virus — the virus that causes cold sores — might trigger Alzheimer’s, but also that common medical treatments like vaccination, antibiotics, and nonsteroidal anti-inflammatory drugs (NSAIDs) are linked to a lower risk of this disease.
Herpes virus may increase Alzheimer’s risk
A study published in the journal Cell ReportsTrusted Source in January 2025 identified a link between infections with the herpes simplex virus-1 (HSV-1), which causes cold sores, and the development of Alzheimer’s disease.
“In our study, we detected HSV-1-related proteins in postmortem human brain samples,” Or Shemesh, PhD, assistant professor in the Department of Ophthalmology at The University of Pittsburgh and senior author of this study, told Medical News Today.
This suggests a possible link between the herpes virus and cognitive decline, which previous studies have also found.
Furthermore, research published in the journal mBio in February 2025, which used animal models, identified the potential route through which HSV-1 can penetrate the brain and lead to cognitive impairment.
In this study, mice became infected with this virus through nose exposure. Once in the brain, the herpes virus caused persistent cognitive problems and anxiety in the mice.
Deepak Shukla, PhD, is the study’s lead author, the Marion H. Schenk Esq. Professor in Ophthalmology for Research of the Aging Eye, and professor of microbiology and immunology at the University of Illinois College of Medicine.
In a press release, Shukla explained how this might work in humans:
“If an infected individual is shedding virus via tears, it could reach the nasal cavity, where it could go more directly to the brain. I think [this infection is] underdiagnosed and understudied, but the neurological consequences, we believe, are much more severe than you would normally see with fever blisters or ocular infection.”
Vaccines, antibiotics, and antivirals may help protect brain health
If viruses such as HSV-1 and potentially other pathogens could increase a person’s risk of cognitive decline, it may not be surprising that according to recent evidence, vaccines, antiviral drugs, and antibiotics could play a protective role in brain health.
That was the conclusion drawn by a review of the existing evidence, which appeared in Alzheimer’s and Dementia: Translational Research & Clinical InterventionsTrusted Source in January 2025, and which analyzed data from 14 studies including over 130 million people.
The review found that antimicrobial medication, vaccines, and NSAIDs were linked to reduced dementia risk.
Ben Underwood, MA, PhD, FRCPsych, from the Department of Psychiatry at the University of Cambridge and the Cambridgeshire and Peterborough NHS Foundation Trust in the United Kingdom, who was one of the review authors, stressed in a press release that “we urgently need new treatments to slow the progress of dementia, if not to prevent it.”
According to Underwood:
“If we can find drugs that are already licensed for other conditions, then we can get them into trials and — crucially — may be able to make them available to patients much, much faster than we could do for an entirely new drug.”
At the same time, review co-author Ilianna Lourida, PhD, from the National Institute for Health and Care Research Applied Research Collaboration South West Peninsula (PenARC) at the University of Exeter, U.K., cautioned that people should not alter their medication use based on these findings without first consulting a physician.
“It’s important to remember that all drugs have benefits and risks. You should never change your medicine without discussing this first with your doctor, and you should speak to them if you have any concerns,” she advised in her press release statement.
Aspirin, ibuprofen linked to lower dementia risk
Adding to the evidence highlighted in this review, a study published in the Journal of the American Geriatrics SocietyTrusted Source in March 2025 also found that long-term use of certain NSAIDs is linked to a lower risk of dementia.
The research, which analyzed data collected from 11,745 participants, found that the use of NSAIDs — such as ibuprofen and aspirin — for a period of over 2 years was associated with a reduced dementia risk.
However, NSAID use did not appear to lower the risk for cognitive decline in people who had a genetic predisposition for dementia.
Some anti-inflammatory drugs, like ibuprofen, can help lower levels of beta-amyloidTrusted Source in the brain. Since the overaccumulation of this protein is associated with dementia, this may explain, in part, the protective effect that some NSAIDs appear to have in the long term.
However, the study noted that NSAIDs like aspirin, which do not have beta-amyloid-lowering properties, were actually associated with a greater decrease in dementia risk.
Vernon Williams, MD, a sports neurologist and founding director of the Center for Sports Neurology and Pain Medicine at Cedars-Sinai Orthopaedics in Los Angeles, who was not involved in this research, told MNT that:
“The findings that the association was stronger for non-amyloid-lowering NSAIDs compared to those with known amyloid-lowering properties is interesting in that it implies the mechanism of action may not be entirely related to amyloid reduction. So other anti-inflammatory pathways and/or genetic risk factor effects may be contributing to the benefits.”
However, like other experts, Williams also cautioned that people should not alter their medication regimen without medical supervision, as “there are potential side effects and risks associated with currently available NSAIDs.”
FEATURED
The Difference Between Dyskinesia and Tremors
Learn how to tell if the involuntary movement you’re experiencing is tremor or dyskinesia.READ MORE
- Alzheimer’s / Dementia
- Neurology / Neuroscience
- Seniors / Aging
Share this article
Written by Maria Cohut, Ph.D. on March 18, 2025 — Fact checked by Jill Seladi-Schulman, Ph.D.
Latest news
- Anti-amyloid drug may help reduce the risk of early-onset Alzheimer’s by 50%
- Scientists unveil how key protein malfunctions and leads to Parkinson’s
- Is excessive sleepiness as we age a warning sign of dementia?
- Study finds why ‘night owls’ have a higher risk for depression than ‘early risers’
- Is brain inflammation at the core of cognitive decline? What latest research says
Was this article helpful?
In Conversation: New directions in dementia research
Millions of people around the world live with a form of dementia, which severely affects both their own and their carers’ quality of life. The specific causes behind dementia remain unclear, but researchers are making steady progress in finding out more about its mechanisms. This instalment of In Conversation looks at some of the realities of dementia, and presents new directions in dementia research.
Share on PinterestDesign by Andrew Nguyen.
Dementia is a neurocognitive syndrome that refers to a collection of symptoms related to memory loss and the decline of cognitive function.
The most common form of dementia is Alzheimer’s disease, which affects millions of people worldwide. According to data from the Centers for Disease Control and Prevention (CDC), in the United States alone, in 2020, as many as 5.8 millionTrusted Source people had Alzheimer’s disease.
Research conducted by the Alzheimer’s Society in 2019 indicates that over 850,000 people were living with dementia in the United Kingdom that year, and globally, more than 55 millionTrusted Source people live with dementia, according to the World Health Organization (WHO).
There are some treatments that can help alleviate some dementia symptoms, but most forms of dementia are currently incurable, and researchers continue to investigate the mechanisms through which this syndrome develops with a view to developing better treatments and prevention strategies.
In our latest instalment of In Conversation, we spoke with Paula Field, who is a caregiver for her mother who lives with Alzheimer’s disease, and with Dr. Kamar Ameen-Ali, who is a lecturer in biomedical science at Teesside University in the United Kingdom, and who specializes in neurodegenerative diseases, including Alzheimer’s.
This article provides an edited and shortened record of this instalment of our podcast. We have added reference links to key research findings mentioned in it. Please listen to the podcast — below or on your preferred platform — for the full discussion.
Dementia: Definition and genetic risk
Dr. Hilary Guite: Let’s start with an overview of dementia and its causes.
Dr. Kamar Ameen-Ali: I always think that it’s good when we are discussing dementia to start off with a definition of what we mean by it. Often you might hear people use it interchangeably with things like Alzheimer’s disease, but they’re very distinct things.
Dementia, we kind of describe it as an umbrella term. It describes a set of symptoms, it’s a clinical syndrome — those symptoms are often associated with memory impairment. But for a diagnosis of dementia, you also have to have an impairment in one or more other cognitive domains as well — this might be personality, it might be visual-spatial skills, for example.
And as I mentioned, dementia as a clinical syndrome is distinct from something like Alzheimer’s disease, which is a type of brain disease that leads to dementia.
Dr. Guite: Is dementia hereditary?
Dr. Ameen Ali: It depends on what brain disease we’re talking about. So if we’re going to talk about Alzheimer’s disease — which I think is a good idea, because it’s the most common brain disease that leads to dementia — there are some types of Alzheimer’s disease that are hereditary and some types that aren’t.
The most common type of Alzheimer’s disease is what we call sporadic Alzheimer’s disease, and that counts for 97% of Alzheimer’s disease cases. So 3% of cases of Alzheimer’s disease will have that known genetic origin, and this is caused by genetic mutations.
So only a small percentage of actual Alzheimer’s disease cases have got that genetic, known hereditary link.
The real-life impact
Dr. Guite: Thank you. So Paula, you’ve been looking after your mother with dementia alongside working. Can you tell us what you first noticed?
Paula Field: Yes, I am. I think my sister and I first noticed that there were some issues with her memory after my father had died. I think that she had started to develop some form of dementia before that, but [our parents] sort of helped each other out. And I think [our father] helped her through a lot of those daily things.
After he died, I think it became much more obvious [that something was wrong], but, you know, at that stage, we weren’t sure whether [her symptoms were] sort of a grief thing. But it gradually progressed. And it probably took us about 6 months or so after he died to realize that, you know, we probably did need to take her to the doctor, and to find out what was happening.
Dr. Maria Cohut: Paula, how did this affect you and your sister financially and during day to day life?
Paula: Well, I think in the early days, you could have a conversation [with our mother]. [My sister and I] were both working full-time, we’d go visit weekends, so we were there really regularly. In terms of financial impact, at that stage, there wasn’t very much, we just carried on as usual. We didn’t have any [additional] carers or anybody at that stage, we used to just go in as often as we could.
Then, once it got to the point when we had to take her to the doctors for her first memory test, and once the results came back, that’s when we had to start thinking about [arranging] more care. And that’s resulted in my sister having to take a day off a week from her work and spend two afternoons a week with my mom.
She has been doing that for nearly 4 years now. And we have other carers going in about twice a day now want to make sure that she gets up, and give her some lunch and the other one in the evenings, to give her some dinner. They do that about 4 days a week, and we pick up the rest.
Learn More About Alzheimer’s
0 seconds of 0 secondsVolume 0%
…
[Message clipped] View entire message
https://meet.google.com/call?authuser=0&hl=en-GB&mc=KAIwAZoBFDoScGludG9fZW15MzQwand1YnVzogE7GgIQADICUAA6AhABSgQIARABWgIIAGoCCAFyAggBegIIAogBAJIBAhABmgEEGAEgAKIBAhAA4gECCACyAQcYAyAAKgEwwgECIAHYAQE&origin=https%3A%2F%2Fmail.google.com&iilm=1742567591911
Leave a Reply