Do viruses trigger Alzheimer's?

economist.com

211 points by helsinkiandrew a month ago


helsinkiandrew - a month ago

https://archive.ph/bxpk0

A_D_E_P_T - a month ago

Very interesting.

Memantine is an antiviral/nootropic (NMDA agonist) that's considered one of the best conventional therapies for Alzheimer's. For e.g., https://pubmed.ncbi.nlm.nih.gov/32914577/

Amantadine is a related compound that's seemingly more potent as an antiviral, and less potent at the NMDA receptor.

Medical hypothesis: This makes me wonder if amantadine might be an effective drug in Alzheimer's treatment. It would come as a total shock to the med chem community if memantine's activity had to do with its suppression of viral replication, and much less to do with its activity at the NMDA receptor.

As an aside, the Russians have a similar drug called bromantane which is sold OTC as a sort of mental energy booster. It's not really a stimulant, and its effects are mild enough for daily use. It might also be very interesting in this context. https://en.wikipedia.org/wiki/Bromantane

zhivota - a month ago

I think there is something to viruses being a big agent of aging. I'm 40 and recently came down with a bad case of norovirus, followed by some kind of flu-like thing. 3 weeks of illness. Afterwards, I felt as if I had aged 10 years, and looking into the mirror it was like looking at what I will probably look like at 50.

It made me wonder how much of aging is mediated by damage from infection, which we fight off, but come out of weaker for it.

It certainly makes me want to double check all my vaccines, and once my kids are older, practice a little better hygiene including things like masking up in tight spaces (pretty much impossible with a 6 and 9 year old in the house, they are the vector right now).

acallaha - a month ago

> A group of researchers mostly based at Columbia University are testing whether valacyclovir, an antiviral used against HSV1, can slow down cognitive decline in people with early stage Alzheimer’s. Between 2018 and 2024, the researchers recruited 120 patients and treated half with the antiviral.

Outsider view: while I'm excited we're making progress, I can't shake a feeling of sadness that the best we could manage was a study this small, started 7 years ago. If it's as pivotal as the article suggests, one would hope we could get more than 60 people in the experimental arm (IIUC this antiviral is widely prescribed, well-tolerated, and off-patent). Nonetheless, excited to see the outcome

pedalpete - a month ago

We cannot ignore that we know so little about how Alzheimer's works, we are potentially lumping multiple diseases under the same label.

The amyloid hypothesis doesn't have to be wrong for the T3D to be true, and the viral potential to also be true if we are looking at 3-5 different diseases that have similar presentations. This also somewhat suggests why it may be the most common form of dementia.

I work in the neurotech/sleeptech space (https://affectablesleep.com) and there is a strong link between sleep quality and Alzheimer's. It is theorized that AD is more common in women due to the lack of sleep through child-rearing and menopause, which decreases the brain's ability to remove amyliod/tau. Of course, this is only relevant to the amyliod hypothesis.

vjk800 - a month ago

I don't know what it looks like from the perspective of someone in the field, but just as someone who is interested in this sort of stuff, it seems more and more plausible that quite many of diseases that have grown more prevalent in the last century, especially autoimmune diseases, are cause by viruses.

It makes sense: the viral pressure has increase by a lot due to both increase in population density and increased travel across the world. At the same time there has been an increase in many autoimmune diseases, many types of cancer, Alzheimer's disease, etc. Also, from some proven cases, we know that viruses can trigger serious diseases (MS disease, type 1 diabetes).

roenxi - a month ago

The part of these sort of conversations that makes me wary is this understanding that "Alzheimer's" is a disease with a single cause. I think it is beyond question that some viruses trigger Alzheimer's, because viruses can do pretty much anything. The real question that they're studying is to what extent do viruses cause Alzheimer's. If it turns out that most Alzheimer's cases are a Herpes symptom then that sounds big.

tim333 - a month ago

Along similar lines there was a good article in the Guardian: The brain microbiome: could understanding it help prevent dementia? https://www.theguardian.com/lifeandstyle/2024/dec/01/the-bra...

Apparently viruses and also bacteria and fungi getting in the brain and causing problems are quite common.

MPSFounder - a month ago

Can someone explain to me how it can be so hard to track down the exact cause for this disease? My grandma passed from it. It seems to be relatively common. What makes this so difficult to treat relative to other diseases? Freshman year of college I was told it was amyloid proteins. Then make a drug to eliminate them. I am having difficulty seeing how 20 years since my grandmother passed, the cause still shows as unknown on reputable sources.

paul_h - a month ago

"Alzheimers-like" is a thing too: https://www.research.uky.edu/news/uk-researchers-find-alzhei... (after covid). I am sure there were other studies, but I'm darned if I can find them after searching just now.

ekianjo - a month ago

> Two other studies, one by GSK, a pharmaceutical company, and another by a group of academics in Britain, also reported that a newer “recombinant” vaccine, which is more effective at preventing shingles than the live version, appeared to confer even greater protection against dementia.

"confer" is something you use for a proven link with an interventional study, not for some random link you found within the thousands of variables you went fishing for in your observation study dataset.

torcete - a month ago

Wouldn't this theory be easy to prove by sequencing brain tissue samples from deceased patients?

Probably more than 90% of the reads would be human, but still.

elif - a month ago

Do we really need questions as headlines?

It's bad enough that people fail to contextualize or deeply consider the reality behind sensational headlines, but when you open the door to vague questions as headlines, you are somehow journalistically allowed to memetically plant a known lie into the zeitgeist of the majority of internet users who read the headline but dont click to read the article.

nraynaud - a month ago

It's really surprising that with all the statistical tools we have, the signal for the link between a common virus and a disease is unclear. Even if the road to a proven intervention is long, you'd think at least the link would be clear.

SubiculumCode - a month ago

and 20ish percent of autism. See maternal immune over-activation.

mariaerica - a month ago

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mariaerica - a month ago

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patriciarudh234 - a month ago

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narrator - a month ago

This is why methylene blue has been so successful in Alzheimer's research. It's antimicrobial and gets into the brain easily.

smeeger - a month ago

the debunked theory that certain diseases like alzheimer's and autism are caused by viruses cannot be true because that would mean that they are caused by inflammatory insult and that would mean that vaccines contribute to or cause certain diseases. this is dangerous thinking and should not have a platform anywhere