[HN Gopher] Hearing aids slow cognitive decline in people at hig...
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       Hearing aids slow cognitive decline in people at high risk
        
       Author : gardenfelder
       Score  : 120 points
       Date   : 2024-01-31 17:47 UTC (5 hours ago)
        
 (HTM) web link (www.nih.gov)
 (TXT) w3m dump (www.nih.gov)
        
       | gardenfelder wrote:
       | > Hearing aids reduced the rate of cognitive decline in older
       | adults at high risk of dementia by almost 50% over a three-year
       | period.
        
       | m3kw9 wrote:
       | Sounds like if you stimulate your brain more your brian is less
       | likely to "atrophy"
        
         | Night_Thastus wrote:
         | This seems to be backed up by a lot of other things. Social
         | activity especially seems to be useful for preventing decline.
        
         | magicalhippo wrote:
         | Which to me shouldn't be that surprising given that we know
         | neurons seek to connect with other neurons based on activation
         | patterns, and that the brain stays plastic into old age.
         | 
         | I've seen similar with movement. Once they break a hip or
         | something which severely reduces their physical activity level,
         | cognitive abilities usually go downhill fast. Part of that is
         | probably cardio-related, but I've long thought it was related
         | to lack of stimulus.
         | 
         | Just doing the dishes or feeling the wind creates a ton of
         | sensations, and may trigger memories, that sitting in a chair
         | watching daytime TV just won't.
        
           | jeltz wrote:
           | I wonder if some of that could be solved via VR or even just
           | video games. Not as good as the real thing but should be more
           | mentally stimulating than passively watching.
        
             | austinjp wrote:
             | There's a ton of research into this idea, have a search on
             | PubMed.
             | 
             | Unfortunately it suffers from at least two problems.
             | 
             | First, generalisable effects from specific interventions
             | often fail to replicate, so for example subjects tend to
             | get better at a specific task but it doesn't necessarily
             | carry over to real-world contexts. There are a few
             | promising potential directions, although even those results
             | are modest and uncertain.
             | 
             | Second, people with even mild/early signs of dementia are
             | extremely unlikely to continue with an intervention. Even
             | if they do they often modify it, e.g. unplugging a smart
             | device to save energy, or taping over buttons to prevent
             | accidentally pressing them.
             | 
             | I would hunt out references but I'm on mobile, they
             | shouldn't be hard to find.
        
           | FrustratedMonky wrote:
           | Seems like this is saying something different.
           | 
           | If it was purely lack of hearing leads to atrophy and neural
           | decay, then why are deaf not all just in steady decline and
           | dying off?
           | 
           | There must be more to it, why can't people that loose hearing
           | later, learn sign language, and thus stay active, just like
           | the deaf.
        
             | Jensson wrote:
             | > why can't people that loose hearing later, learn sign
             | language, and thus stay active, just like the deaf.
             | 
             | Did their friends and family learn sign language as well?
             | People who are deaf young tend to get a social circle who
             | can communicate with deaf people, while old people are
             | unlikely to rebuild all of that.
        
             | bluGill wrote:
             | Very few adults learn a new language to a high level. It
             | can be done, but most get to the level of ordering a beer
             | and call it good if they get alcohol.
             | 
             | If you don't need to use the language except for a one week
             | tour (where you are still mostly with people who speak your
             | language) this is good enough. However if you are suddenly
             | without ability to communicate you probably can't suddenly
             | learn fast enough to combat decline.
        
       | magicalhippo wrote:
       | Seems rather unsurprising, given what we already know of the
       | brain. Though I guess specific studies like this is more
       | actionable.
       | 
       | Good thing hearing aids have become more affordable lately, from
       | over-the-counter models to DIY style using cheap microcontrollers
       | for developing countries.
        
       | dblohm7 wrote:
       | My spouse is an audiologist, and yes, she has told me (and of
       | course her patients) this is very much a "use it or lose it" type
       | of deal.
        
         | loco5niner wrote:
         | Would you be willing to clarify that? Is she talking about
         | losing cognitive abilities when someone fails to get hearing
         | aids when they should? I'm starting to deal with some hearing
         | issues and would like to make sure to stay on top of this
         | issue.
        
         | TedDoesntTalk wrote:
         | Use what or lose it? Hearing? Cognition?
        
           | chaostheory wrote:
           | Most likely hearing, but that's strongly related to
           | cognition.
        
       | sp332 wrote:
       | Interesting that another Lancet paper on this topic was recently
       | retracted. https://news.ycombinator.com/item?id=38894636
        
         | AlexErrant wrote:
         | The retracted paper discusses an _association_ since it was
         | _observational_ :
         | 
         | > We used Cox proportional hazards models to estimate hazard
         | ratios... between self-reported hearing aid use status (hearing
         | loss with or without hearing aids) at baseline and risk of
         | dementia
         | 
         | The top-level article discusses a _randomized controlled study_
         | and therefore can make a much stronger claim of _causality_ :
         | 
         | > The researchers randomly assigned participants to one of two
         | interventions. About half received hearing aids and instruction
         | in how to use them. The other half were assigned to a health
         | education program focused on promoting healthy aging. Both
         | groups received follow-up visits every six months to reinforce
         | the training.
        
       | augustk wrote:
       | What about people who are completely deaf since birth?
        
         | robg wrote:
         | Different mechanisms, you're born with ~100x the amount of
         | neurons you'll have as an adult, those normally used for
         | hearing get adapted and trained on other stimuli.
        
         | jauntywundrkind wrote:
         | Make sure their glasses prescriptions are up to date & that
         | they are engaged with the world (and not slipping away) too.
        
         | wirrbel wrote:
         | I would assume they compensate with other senses and so if they
         | get blind at high age they are at equal risk.
        
         | thomastjeffery wrote:
         | There is no pre-existing neutral training in a newborn's brain.
         | 
         | Adults who become deaf lose a stimulus that their brains are
         | already trained to use.
        
       | wirrbel wrote:
       | Isn't that common knowledge? Or let me rephrase this: this can be
       | observed by laypeople in their communities.
       | 
       | I am glad that it's also scientifically studied if the body of
       | evidence hasn't been large enough so far
        
         | ben_w wrote:
         | I suspect most people think that both are caused by old age,
         | rather than that deafness causes (or accelerates) dementia.
         | It's not like there's a well known group of congenitally deaf
         | people who get dementia young to inspire a causal connection.
         | 
         | My mum started noticeably losing her hearing _after_ her
         | dementia symptoms got quite bad. She may well have lost her
         | hearing sooner and we just didn 't notice, just as in
         | retrospect there were huge warning signs of dementia well
         | before the diagnosis and we just didn't realise what we were
         | observing.
        
           | joombaga wrote:
           | May I ask what the huge warning signs were?
        
             | ben_w wrote:
             | Thinking I was born 3 years earlier than I was. Forgetting
             | how to read maps. Higher anxiety causing her to ask me to
             | drive dangerously _slowly_ , and in so doing revealing she
             | didn't know the speed limit on that category of road.
             | Forgetting to renew her road tax (I have no idea how she
             | wasn't fined for that, given the rest of the family noticed
             | this six months after it was due).
        
           | jdietrich wrote:
           | _> It's not like there's a well known group of congenitally
           | deaf people who get dementia young to inspire a causal
           | connection._
           | 
           | Hearing ability and cognitive ability are significantly
           | correlated, independent of age.
           | 
           | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8581793/
        
             | ben_w wrote:
             | The important point was "well known", in this context by
             | the general population rather than to subject experts.
        
       | bilsbie wrote:
       | Alternate headline: people who take actions to be more social
       | slow cognitive decline.
        
         | jeltz wrote:
         | Yes, but this is also a very concrete solution to encourage
         | people to take more actions.
        
         | rqtwteye wrote:
         | It's not that simple. If you have hearing problems it can be
         | quite difficult to be social no matter how hard you try.
        
       | waterhouse wrote:
       | A randomized intervention! Huzzah!
       | 
       | > The researchers randomly assigned participants to one of two
       | interventions. About half received hearing aids and instruction
       | in how to use them. The other half were assigned to a health
       | education program focused on promoting healthy aging.
        
         | olliecornelia wrote:
         | What are you advocating
        
           | waterhouse wrote:
           | I'm advocating that people do studies with randomized
           | interventions--an approach that is capable of proving
           | causation--and not being satisfied with purely observational
           | studies that look at correlations, which are often hopelessly
           | confounded and can't distinguish between "X causes Y" and "Z
           | causes both X and Y". I was pleasantly surprised to find that
           | this study was of the first type rather than the second.
        
             | hombre_fatal wrote:
             | While this take seems popular, this isn't a good way of
             | looking at it because, in my experience, it seems to lead
             | to the dismissal of good evidence or it suggests that we
             | can't build confident causal inferences without a certain
             | study. For example, RCTs are also observational, and it's
             | incorrect to say they can uniquely detect causation.
             | 
             | I think a more helpful way to look at research is to look
             | for a convergence of outcomes across the evidence, like a
             | bunch of needles of various sizes pointing in the same
             | direction (or not) on a gauge. And where there are
             | divergences, and there always will be, which differences in
             | methodology can explain them.
        
               | waterhouse wrote:
               | > RCTs are also observational
               | 
               | The key phrase is "purely observational". Now,
               | occasionally you end up with a "natural experiment" in
               | which some accident has effectively done the
               | randomization for you--specifically, where the mechanism
               | that puts people in the treatment group vs the control
               | group is something you can be very confident has no other
               | causal interactions. This was a good example: https://twi
               | tter.com/PGeldsetzer1/status/1661776663074738176
               | 
               | "Causal evidence that herpes zoster vaccination prevents
               | a proportion of dementia cases [...] To provide causal as
               | opposed to merely correlational evidence on this
               | question, we take advantage of the fact that in Wales
               | eligibility for the herpes zoster vaccine (Zostavax) for
               | shingles prevention was determined based on an
               | individual's exact date of birth. Those born before
               | September 2 1933 were ineligible and remained ineligible
               | for life, while those born on or after September 2 1933
               | were eligible to receive the vaccine."
               | 
               | But any time you're looking at a scenario where treatment
               | vs non-treatment was the result of individual human
               | choices, that opens up a potentially very wide range of
               | ways for something you didn't know about (and potentially
               | something difficult to accurately control for even if you
               | do know about it) to cause treatment and cause the
               | outcome, instead of the treatment causing the outcome.
               | 
               | > it suggests that we can't build confident causal
               | inferences without a certain study
               | 
               | I do think there's an upper limit to the confidence you
               | can justifiably hold, and that it's often not very high.
               | Consider the studies that observe "A bit of alcohol
               | correlates with better health than zero alcohol". You
               | control for wealth, education, and maybe other things,
               | and the apparent effect remains. How high confidence
               | should you have in the result? Then someone realizes:
               | Some fraction of people who consume zero alcohol do so
               | under doctor's orders because they have health problems,
               | and if you exclude those people then the effect
               | disappears.
               | 
               | No matter how many causal pathways you think you've
               | controlled for, how confident can you really be that
               | there isn't a new one you haven't thought of? (And
               | controlling has its own perils: if your measurements are
               | noisy, or if you end up controlling for the outcome.)
               | 
               | > it's incorrect to say they can uniquely detect
               | causation
               | 
               | Oh, correlational studies can "detect" causation, but the
               | hard part is being certain that the thing detected isn't
               | a false positive.
        
               | TylerE wrote:
               | And it'll also include some number of alcoholics in
               | recovery who are currently consuming no alcohol, but
               | who's bodies have hard years on them, and you'd expect to
               | do worse than overall population average in outcomes.
        
             | LeifCarrotson wrote:
             | I completely agree that randomized intervention studies
             | have enormous value when compared to observational studies.
             | 
             | In this example, it would be particularly hard to establish
             | a causative relationship that said "hearing aids inhibit
             | dementia" or "hearing loss causes dementia" if instead all
             | you had was a population, some of whom used hearing aids,
             | and some of whom had varying levels of hearing abilities,
             | and some of whom developed dementia. In all the noise,
             | you'd be very fortunate to find that a control group of
             | people with undiagnosed (how would you ever measure that!)
             | hearing loss who failed to get hearing aids had cognitive
             | decline in excess of that experienced by those who did get
             | hearing aids. Here, instead, the intervention is "the coin
             | flip said you're in the hearing aid group/you're in the
             | health education group."
             | 
             | Of course, the murky ethical issue here is that this
             | randomized intervention resulted in some people having
             | poorer hearing, perhaps permanently (use it or lose it!)
             | and some people having more rapid cognitive decline. This
             | randomized intervention directly caused real suffering.
             | Nearly 125 people in the heart-health group with increased
             | risk of dementia onset were assigned to a study that just
             | received health education. For at least three years, they
             | had reduced hearing and a reduced ability to communicate,
             | and after three years, they had significantly greater
             | cognitive decline.
             | 
             | Caution is good, but in general I have no problem
             | personally with the 'shut up and multiply' application of
             | ethics in this case. There are 8 billion people all getting
             | old, and more being born every day who will eventually get
             | older. It's very important as a species to know that
             | hearing aids slow cognitive decline, and if that meant that
             | 119 people were placed at a slightly increased medical
             | risk, 119 divided by 8 billion is a pretty small number,
             | and 7.999999881 billion who are now more likely to get
             | hearing aids and have slower cognitive decline is a lot of
             | positive utility. But it wasn't me or my mom who can no
             | longer hear and who is suffering from dementia, and some
             | will draw a hard line and say that you can't perform
             | studies that will put even a small number of people at
             | increased risk.
             | 
             | We should be careful to evaluate merit and limit harm, but
             | we should perform more randomized intervention studies.
        
         | bluGill wrote:
         | there needs to be at least 3 groups, with the third assigned to
         | both. Otherwise you know one is better than the other, but not
         | if both are good/better
         | 
         | Ideally we would have a 4th: control that we do nothing with -
         | but this is not ethical so we can't. Where you can do this
         | ethically you should do it.
        
       | aksss wrote:
       | Wait, isn't the retraction of this old news by now?
       | 
       | "We should have followed up': Lancet journal retracts article on
       | hearing aids and dementia after prodding"
       | 
       | https://retractionwatch.com/2024/01/04/we-should-have-follow...
       | 
       | "When the paper first appeared, it seemed to confirm a widely
       | held belief - that hearing loss is associated with developing
       | dementia, and using hearing aids can help to reduce risk - about
       | which the scientific evidence has been mixed, Blustein, the
       | hearing loss researcher, told Retraction Watch. In her view,
       | public health messaging and media coverage of the question has
       | been "misleading."
       | 
       | The findings were picked up quickly and disseminated among the
       | community of people following the question of hearing loss and
       | dementia, she said. "I don't think people are necessarily aware
       | of retractions."
       | 
       | Another pull quote:
       | 
       | "Most notably, he found that hearing aid use did not correspond
       | to a lower rate of dementia for people with hearing loss, as the
       | authors reported. He found the opposite: among people with
       | hearing loss, the dementia rate was higher for those using
       | hearing aids."
        
         | sp332 wrote:
         | That one was from UK BioBank data and published in April. This
         | one is from John Hopkins in the USA and was published in July.
        
           | aksss wrote:
           | In context, I would be careful taking this conclusion at face
           | value quite yet, though it does seem intuitive, just as the
           | other one was.
           | 
           | "About 250 healthy older adults came from a long-term study
           | of heart health ... 739 people were newly recruited. . . .
           | Participants recruited from the heart-health study had more
           | risk factors for developing dementia, including being older
           | and having faster rates of cognitive decline than those from
           | the general community.
           | 
           | In the main analysis of all study participants, the
           | researchers saw no difference in the rate of change in
           | cognitive functioning between people who received the hearing
           | aids and those who didn't.
           | 
           | However, when the analysis focused on people from the heart-
           | health study, who had a higher risk of dementia, the benefit
           | of the hearing aids was substantial. Those who received
           | hearing aids had an almost 50% reduction in the rate of
           | cognitive decline."
        
       | Vicinity9635 wrote:
       | Fun fact: auditory signals are the fastest path to human
       | reflexes, way faster than vision. I forget the exact numbers, but
       | visual reactions are on the order of 300ms whereas auditory
       | reactions are sub 100 IIRC. Feel free to correct me if anyone can
       | find numbers.
       | 
       | So all those blind fights in the matrix cartoons or daredevil are
       | sill, but not quite as silly as you might have expected. There is
       | actually a significant reaction time advantage. But good look
       | hearing a sword swing at your face vs your leg lol
        
         | gpt5 wrote:
         | There is a difference, but not that dramatic. You can try it on
         | yourself here - https://playback.fm/audio-reaction-time
        
           | Vicinity9635 wrote:
           | There's a lot more between the actions there image to
           | display, mouse to computer that have nothing to do with
           | internal meatbag reactions. Especially when we're already
           | measuring in milliseconds.
        
             | gpt5 wrote:
             | I'm referring to the paper cited in the linked site, which
             | quotes about 50ms of difference in reaction time between
             | auditory and visual, not 200ms like stated in the comment
             | above.
        
       | nyrikki wrote:
       | As social isolation was associated with about a 50% increased
       | risk of dementia this isn't surprising.
       | 
       | https://nap.nationalacademies.org/catalog/25663/social-isola...
        
         | Overtonwindow wrote:
         | Makes you wonder if social isolation is a cause of dementia,
         | thinking less means less brain stimulation.
        
       | mrangle wrote:
       | Deaf-infant cochlear implants can make a significant difference
       | in IQ (less language audio input affects IQ if not mitigated
       | ASAP: a principle that extends from deaf to normal hearing
       | children). With this principle in mind, it isn't surprising that
       | hearing aids slow cognitive decline later in life. Though, I'm
       | not implying that it may be a 1:1 mechanism.
        
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