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This adds to compounding evidence that cognitive decline (including dementia and Alzheimer) is significantly delayed by mental stimulation.

Hearing is just part of it.

After watching my formerly very sharp grandparents retire from very active and stimulating jobs (nursing, and investing respectively) decline hard I've soured to the idea of the standard retirement.
Counter-anecdote: my grandfather retired "early" (in today's view) at 55 and dementia wasn't a major problem until his 80s. He had several great decades of retirement. (Partly because he had several pensions and good social security.)

If anything, "standard retirement" of people only allowed to retire at 65 or 70 seems to intentionally pushing up against the limits of human stamina and decline hitting hard soon after retirement almost an intentional "feature" of the current standard because society can spend less on pensions and social security if we just require everyone to work until they break.

Anecdotally feels to me like more evidence we should roll back the decadal encroach of retirement age into way too late in life to enjoy it and return to better pensions and social services.

This may be true in some cases, but there are aggressive forms of cognitive decline that are not affected by mental stimulation. Early-onset Alzheimer's tends to be a very good example of this.
Terry Pratchett was about as mentally stimulated as a human being can be.

Perhaps that helped delay his case, perhaps it didn't, but it's very clear that stimulation is no guarantee.

This is an example of sitting on the couch all day vs getting hit by a car for physical decline. Sure, there are extreme cases, but consistent long-term inactivity causes decline in every area of life. This is very well-known in circles researching stroke recovery - a lot of functionality can be restored, but only with significant active effort (both mentally and physically).
Mental stimulation is discussed here in the comments, and that makes sense, but I wonder if social connection could be a factor as well.

Loneliness and disconnection with others seems correlated with all kinds of declines. If you can't hear people it's very hard to participate, which could make you more disconnected.

I read that hearing aids might be deregulated soon, which might mean lower prices and more innovation there.

I feel like this has happened with my grandmother. She’s in her 90s and mostly still there, but she has outlived my grandfather and most of their friends. She’s also quite feeble and didn’t leave the house, and broke her hip this year (and miraculously made it through a very risky surgery). Family members in the area visit her often and she has a live in care taker, but the last few years she’s started to have minor delusions. Mostly, she’ll talk about seeing “little people” in the yard. If you have a conversation with her, she’s as present as most people that age I’ve interacted with.

I suspect she basically has low-grade cabin fever. The delusions only started shortly after her husband passed and she was alone. Even putting aside the concerns about the elderly driving, my grandfather insisted on driving everywhere so she essentially couldn’t drive to see people. She hasn’t been strong enough to really cook or clean outside of very simple tasks in a while. Her only real stimulation is / was when we visit.

I was going crazy when quarantining with Covid for 7 days, and I felt any mild social interaction taxing afterward for another week or so because that muscle was atrophied (I’m not particularly introverted or shy). I can’t imagine being confined to one room of a house hoping someone visits me for an hour each day as my only source of interaction with the world.

On the flip side, I did some work for an emeritus professor when I was in undergrad. The guy was 89, came in 4 days a week to work on his (successful) hobby project invention, was sharp as a tack, and could solder SMD components with steadier hands than me. The only reason he even needed my help was he never learned to code (he was well into tenure by the time programming a PC became necessary for his research so grad students handled that and then hired undergrads when he stopped running a lab).

Both examples are anecdotal evidence, and maybe I’ll have a different opinion when I’m older, but the traditional full retirement if you are otherwise healthy seems like a good way to waste away. I think having some responsibilities keeps you connected, energized, and motivated to keep living.

I have pretty bad hearing loss, I'm "insured", but after insurance my prescription hearing aids would cost me 12k. I guess I'll add dementia to my bucket list
In the US, hearing aids are now available without a prescription or audiologist. From what I've been reading, some are quite good and others are crap, but perhaps you can find something reasonable.
Many are quite good, drop-in replacements for the doctor-prescibed ones of yesterday.

Tuned by you, at home via your phone.

I would also encourage you to check them out!

That’s wild and unfortunate. Just curious: don’t you hit your deductible far before paying the full 12k? Or is there an exception for hearing aids. Also, isn’t the prescription requirement for hearing aids being waved?
How do deaf people play into this? I know they use sign language to communicate but what about all the other stimulation they miss like being able to hear radio, tv, music, random conversations, etc.
Doubt it applies. Growing up deaf, you'd have wired your brain to pay attention to other information sources than the audio stream.
I understand, but I was under the impression the article is attributing a degraded audio stream as a greater chance or risk of Alzheimer's.
There have many studies over the past decade to try to determine why people with hearing loss tend to have worse cognition...

The article doesn't make that assertion. It does provide three plausible explanations for increased cognitive decline in people with hearing loss.

my father has had hearing loss for over two decades now, slowly starting in his early forties. it's so bad now in his early 60s that it's almost impossible to have a conversation with him. he's also been laid off of his tech job a couple of years ago and has retreated into isolation with his dogs. my mother thankfully still exists in his life but his cognitive decline is so noticeable it's extremely sad. he misunderstands everything, and english as a second language has made his life in the USA that much more difficult. it's quite insane the difference between him now and him even 10 years ago when he had a job and somewhat of a community.

he's bought some hearing aids but it doesn't help that he's a cheap person and spent a grand total of ~90$ on them from some random store (amazon?) so suffice to say they do almost nothing aside from make high pitched sounds. I've told him to go to the doctor to buy something a bit more advanced, really look into it, but he won't and i think his decision making is part of the cognitive decline. he simply doesn't seem to care anymore. if it were up to me i would buy him some really amazing ones, but he won't even go to the doctor to seek help to diagnose what type of hearing loss he has so it'd be a waste of money.

i've had this theory that his hearing loss is isolating him so much that it's affecting his ability to think, so i am not surprised at all by this study

I don’t know if it will help, but if going to a doctor is something he resists, an alternative depending on where you are might be to go to Costco and get a hearing test, and buy a hearing aid from them.

Hearing aids are also available over the counter in the US and I haven’t tried them. My understanding is that you need to do the hearing test yourself and they guide you through it.

I can’t tell from your description if it’s anything wrong with the hearing aids or it’s about getting them adjusted properly. Feedback will happen even with pricey hearing aids, but a decent pair will automatically cut out before it gets too bad, and it should go away if you have them in your ears far enough.

Would this suggest that having background noise on in your home (e.g. music, TV, podcast, etc.) is beneficial?

Our home is generally pretty quiet. I occasionally listen to music, but we only have the TV on when we're actually watching something (which isn't often).

Compared to growing up (and even still today) my Mom would leave live TV on constantly in the background.

Obviously we still have mental stimulation through work, cooking, board games, reading, etc., but not much audio (aside from conversing and the occasional video game/TV show).

Yes, in theory. Not so much noise, but speech. And specifically speech that you are engaged with, most likely. Versus speech to which you aren't paying much attention.

Normal child development is uniquely contingent on the child hearing a lot of speech.

It is known that unless deaf people get cochlear implants at the youngest possible age, their intellectual development risks being stunted due to lack of heard language.

Which begs the hypothesis that a positive effect of hearing aids in prevention of cognitive decline is due to maintenance of heard speech.

A related hypothesis might be that any correlation between a high degree of social activity and less cognitive decline is, at least in part, due to the same mechanism. As could be any correlation to playing chess, etc, due to this hidden variable.

Children need to be exposed to language. It doesn't need to be a spoken language. Deaf people can do very well.
> my Mom would leave live TV on constantly in the background.

What on earth? I've never heard of anyone doing this. Why would one want this?

I know some people do that with the radio which I also consider really annoying.

Both of my parents (long ago divorced) do this. I have always thought of it as a generational thing.
I saw that white noise was suspected of increasing the risk of dementia. I wonder if hearing aids improving the clarity of background noise might offset that risk.
Is this a correlation->causation thing, where people who experience significant hearing loss also experience dementia more than healthier people who have healthy ears and healthy brains?
Irrespective of the (possible) causative link between hearing loss and dementia, the argument is that hearing loss treated with heating aids reduces the likelihood of dementia.

Anecdotally, I wear hearing aids. I'm always amazed at how much more in contact with the world I feel when wearing them. Without them, all the little background sounds that you perceive are gone. E.g. People chatting. The rustling of your clothes. Birdsong. Running taps. The knocking sound in your car, etc etc. I am totally prepared to believe that the loss of this stimulation increases mental isolation and atrophy.

As a child (with good hearing) I always assumed that I would choose eyesight over hearing if I had to make a choice. Nowadays, it would be a much closer run thing.

I tend to isolate myself from the environment using noise-cancelling headphones.

Now I'm wondering if this might be a bad idea, neurologically speaking...

Depends… what are you listening to on your headphones? Or maybe it doesn’t matter.
I've had hearing loss my whole life and I wear them all the time on most days.

However, I do find a sort of peace not wearing my hearing aids. If the house is empty I usually don't put my hearing aids on for hours in the morning.

Thank you for sharing that I will be thinking about it all day.
How about this, people who experience hearing loss are more likely to have a /diagnosis/ of dementia? Because hearing loss causes them to underperform on the verbally administered evals.

My father in law got a dementia diagnosis, after this my wife and I started going with him to his appointments - and discovered why he had such a diagnosis. He's the type of person who'll nod and pretend to hear/understand when he doesn't. We know this just from our interactions with him. The tool they use to eval is verbal question/answer and he did much better on the evals when we were with him and keyed the doctor in on that they ensure he hears the question or they give it to him in written form.

According to the journal article, they had a control group that didn't receive hearing aids. Also, all the participants in the study had hearing loss.

"Participants were randomly assigned (1:1) to a hearing intervention (audiological counselling and provision of hearing aids) or a control intervention of health education (individual sessions with a health educator covering topics on chronic disease prevention) and followed up every 6 months." from https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

The opening sentence in the article says that introducing hearing aids to high risk dementia patients reduces cognitive decline by up to 50% so I think your question is misguided.
I wear them for tinnitus. But with having ADHD hearing all the background noise so sharp is actually not helping.
Man, I read that wrong
Yet another worthless study proving nothing. Why do we keep funding these? Either show causation of don't bother publishing.
From reading the abstract, the study was a randomized controlled trial. As far as I know, that's the best way to show causation.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

What would make correlation research worthless? Wouldn't that just be a first step to see if researching causation is even worth it?
This is pretty much a canned response from LatteLazy. It ignores the fundamental fact that science has never “proved causation” of anything ever. All we have is lower and higher confidence correlations and that’s all we’ll ever have.
I'll take any confidence at all. This has a zero percent confidence because causation is fundamentally different to correlation. And showing causation is pretty much the whole point of experiments in science. Hence, this is not even science really. Just advertising...
I would not call study worthless, but to establish causation one could do an experiment where elderly adults are given (1) an opportunity for a free hearing test and hearing aids if needed (2) the equivalent amount of cash. Then follow up the two groups to see if group 1 is less likely to develop dementia. My guess is that the results will not be strong.
It becomes worthless when we never take the second step.

It is worthless because why not just jump straight to step 2?

The answer of course is that that would be expensive and hard and might not prove anything. Much safer and cheaper to NOT actually test you hypothesis and you can still use it to up your publication figure and your funder can still use it to sell hearing aids etc...

> It is worthless because why not just jump straight to step 2?

Can you explain what this means?