The Connection Between Hearing Loss and Dementia

John Horton:

Hey there, and welcome to another Health Essentials Podcast. I'm John Horton, your host.

Your ears are closely linked to your brain, and we're not just talking about their location on your head. You see, when your hearing fades, it forces your brain to work harder to keep up with everything happening around you. Over time, this can lead to issues, including dementia. Why does this happen? We're going to dig into that today with neuropsychiatrist Dylan Wint, a specialist in degenerative brain diseases. Dr. Wint is one of the many experts at Cleveland Clinic who pop into our weekly podcast to give us a better understanding of our health. So if you're ready to listen closely, let's learn how hearing loss can affect your brain health and what you can do about it.

Welcome back to the podcast, Dr. Wint. I am always happy to see your name on the guest list.

Dr. Dylan Wint:

Thanks, John. Always happy to get invited.

John Horton:

Well, it's an open invitation, trust me.

Now, when we talk about hearing loss, most people just think of it as an ear issue. But from the sound of it, we've learned that losing your hearing can have a ripple effect on brain health. I don't think that's a one-to-one connection that most folks really make.

Dr. Dylan Wint:

You're right. It's not a one-to-one connection that most folks make. And it also isn't a one-to-one connection that was really being made in the medical community until recently. And even now in the medical community, I think that it's under-recognized. So hearing loss turns out to be one of the largest modifiable risk factors for dementia. So people who have hearing loss have at least twice the risk of developing dementia of those without hearing loss.

John Horton:

Wow, that's a big number.

Dr. Dylan Wint:

It is. And to be honest, if you have mild hearing loss, you have twice the risk. If you have moderate hearing loss, then it's three times the risk. And if you have severe hearing loss, you have five times the risk of developing dementia of someone who has normal hearing.

John Horton:

Wow. Well, this is why we're talking about this. So let's break it down a little bit and get into how hearing loss actually affects our brains. I mean, is it creating changes upstairs there? I mean, what's happening in our noggins when our ears stop working so well?

Dr. Dylan Wint:

Yeah, it's a great question, and one that we didn't understand for a long time. There had been this association between hearing loss and cognitive decline in dementia, but we didn't really understand why. So there are a few things that we can talk about, although this isn't fully understood still.

So one is that when you lose auditory input, when you lose sound, you're not just depriving your ears of sound; you're depriving your brain, specifically your auditory cortex, the area that's responsible for processing sounds into meanings. You're depriving that area of the brain of input. And when you deprive an area of the brain of input, it actually starts becoming … not exactly lazy, but your brain has a lot of stuff to do. And if this part isn't being used, it'll be used for other things.

Now, the crucial thing is that that auditory cortex is very linked to language networks and to memory networks in the brain because we need those networks to process and to store that auditory information. And if the auditory cortex gets reorganized, it results in downstream reorganization of memory and language networks.

John Horton:

Sounds like you start missing pieces of the puzzle with everything that's going on around you, and then that just leaves gaps.

Dr. Dylan Wint:

Yeah. In fact, if your brain is working harder because you have hearing loss just to process the information that's coming in, just to make meaning of it. Then, that means that you are robbing the brain of resources it needs for comprehending the information coming, for storing the information that's coming in. And so there's this vicious cycle where hearing loss causes these brain changes. That part of the brain becomes less efficient, less precise, and so it actually makes it harder to interpret what you're hearing. Eventually, people start to withdraw from conversations. And I've heard many patients say this to me. "Yeah, I don't really get involved in conversations because I can't keep track of what's going on because of my ears." And that social withdrawal, social isolation, actually is a contributor to cognitive decline as well.

John Horton:

Do you actually start to see atrophy in the brain? I mean, are there things that just shrink because it's not being used?

Dr. Dylan Wint:

Yeah, that auditory cortex that I mentioned earlier actually starts to thin out in people who have hearing loss. So yes, there is atrophy, literal shrinkage of the brain from lack of input and stimulation to those areas.

John Horton:

And you explaining that, it makes you really realize how the worse your hearing loss is, the worse that memory loss and those things become with it because the atrophy is just going to get worse and worse and worse as it progresses.

Dr. Dylan Wint:

That's right. Given that the less stimulation you have, the worse these problems in the brain become, the worse your hearing loss is, the less stimulation to those areas, therefore, the more rapidly and severely these changes will occur.

John Horton:

Now, I take it, all of this explains how hearing loss increases the risk of dementia and Alzheimer's — I know things that we were talking about the last time you were with us.

Dr. Dylan Wint:

Yeah. So hearing loss, and probably in a similar way, vision loss, both of these sensory-deprived states, so to speak, do increase the risk for dementia. Again, severe hearing loss increases the risk five times compared to someone without hearing loss. For every 10 decibels of hearing decline someone has, their risk of dementia increases by 20%. And someone who loses their hearing relatively early, like in middle age, 40s, 50s, there's an increasingly strong body of evidence that those folks are at even higher risk because their brain has been exposed to this sensory deprivation state for an even longer period of time.

John Horton:

Yeah. Wow. It makes me feel like I got to turn down the headphones a little bit, the volume. You don't want to damage that hearing.

Dr. Dylan Wint:

You absolutely want to protect your ears if you can.

John Horton:

Now, how much of this, if you start having hearing loss early, and we all, like I said, concerts and things like that, we put our ears through a lot. If you start getting a little hearing loss at an early age, I take it you're just accelerating that process that can lead to these brain health issues later.

Dr. Dylan Wint:

It may not be so much accelerating the process as it is exposing your brain for a longer time to that detrimental effect. So if you lose your hearing at age 50 as compared to age 60, these changes in the networks, the other changes that occur, those are occurring for 10 years longer in the person who loses their hearing at 50 years old.

John Horton:

It sounds like you're putting more of a load on your brain for a longer period of time, which is, eventually, it could lead to those issues.

Dr. Dylan Wint:

It's more of a load, but well, it's more of a load and less of a load. So it's more of a load in that the brain has to work harder, but it's also less of a load in that when that cortex is not stimulated, it decides it'll do something else with its time and its energy.

John Horton:

So what does it do? When that audio cortex isn't doing the sound thing, what does it spend its time on?

Dr. Dylan Wint:

To be honest, I don't think we know. It may be simply conserving energy. So if an area of the brain isn't being used very much, then perhaps you can just give that area some rest and give more blood, oxygen, nutrients to the other areas of the brain. But as far as I know, it's not really clear what that part of the brain then sets about to do. Clearly, it's still engaged somewhat in auditory processing, but the less it has to do, the smaller it becomes.

John Horton:

Yeah. All I can picture with it now is it's like your computer when it's rebooting, and it's just that circle's spinning around. So who knows? That's one of the mysteries of the brain.

Now, you mentioned this as we were talking, that when you don't hear as well, you don't communicate as well with others, and you might withdraw from conversations or even start experiencing some social isolation. How does that fit into the risk or the increased risk of dementia?

Dr. Dylan Wint:

Well, social isolation is one of the main modifiable risk factors for dementia. So someone who is socially isolated has a risk that's about 50% higher of developing dementia than someone who is socially engaged. And the subjective feeling of being socially isolated, loneliness, the feeling of loneliness, also independently increases the risk for cognitive decline. So you have both the risk that's conferred by the hearing loss itself, but then also the risk that's conferred by one of the results of the hearing loss, which is withdrawal from social situations.

John Horton:

Well, it seems like that's a big sign, maybe that you might be experiencing hearing loss. What are some other things that we should look for that might signal that someone's hearing is fading and that it's starting to affect their thinking or memory? Are there some clues that stand out?

Dr. Dylan Wint:

I don't know if there are specific clues that stand out that tell you that someone's memory is being affected by the hearing specifically, but you can tell when someone is struggling to hear. They ask for you to repeat yourself. It's clear that they're not grasping parts of what you're saying. They give you responses that don't seem to match the question or statement that you made. And fortunately or unfortunately, we've all been in situations where we can't hear something that well, and usually, it's explainable by the situation around us.

But if you see those same kinds of things happening in someone where the situation does not explain it or where there's a change — we used to go to dinner in noisy restaurants and he would have no problem hearing me, and now it seems like I've got to yell — those are signs that you should get your hearing checked out.

John Horton:

Yeah. I know with older family members, you go to their house and the TV is just at about the highest level it can get to. I take it that's a sign that maybe hearing isn't working as well as what it should and maybe should get looked at.

Dr. Dylan Wint:

That is a great sign. Now, sometimes, the TV is loud so that someone can go about their day and be across the house and still listen to the TV. But I absolutely agree with you that a loud TV is a sign, especially again, if that TV's a lot louder than it was last year or the year before. Because even if they're doing it to hear across the house, they have to get it to a higher volume to be able to hear across the house.

John Horton:

All right. So we're having these hearing issues and you start ... it seems like it is just a natural part of us getting older. I mean, things just don't work as well. If you take some steps to address your hearing, can you limit this mental decline that might come with it?

Dr. Dylan Wint:

Yeah, absolutely. So I'm not sure that hearing loss is a natural part of getting older, but it is a common part of getting older. And the reason I say that is I don't want people to accept hearing loss as just, Well, I'm getting older, because it has these important downstream effects on cognitive health. The great news is that treatment of hearing loss actually does protect people from cognitive decline in dementia. So in a study called the ACHIEVE trial, they took people with hearing loss, gave some of them hearing aids, and some of them they didn't. And over three years, the risk of dementia was reduced by half in those who had the hearing aids. So that's the good news.

The bad news is that on average, it takes people about seven years from the time they notice their hearing is going bad until the time when they actually go and get hearing aids. So we want people really to respond to evidence of hearing loss rapidly by going and getting their hearing tested. You have to talk to your doctor about changes because some of those changes that seem like they're just aging, they can have meaningful consequences.

John Horton:

Yeah. And then it sounds like once you get those hearing aids, you actually need to use them. I think we've probably all had family members who you know, they have hearing aids and they won't put them in, or they forget to put them in or they're uncomfortable. It sounds like it's really pretty critical that they do get used.

Dr. Dylan Wint:

They really do need to get used because the hearing aid in your pocket does not do anything to increase the stimulation to your auditory cortex, doesn't do anything to help you improve your social engagement.

John Horton:

All right. Well, I'm going to be giving that advice to my mother-in-law because I got to tell you, every time she visits, she never has her hearing aid. Either she just doesn't want to listen to me yap or she just forgets about it, but I'm going to make sure I get on her and tell her it is important to have those in.

Dr. Dylan Wint:

Tell her I said to put them in.

John Horton:

I think it would be better coming from you.

So I guess, Dr. Wint, to wrap things up, what do you recommend that people do to protect their hearing and, I guess, their brain health?

Dr. Dylan Wint:

Well, there are predictable situations where we know our ears are going to be exposed to a lot of noise. For most folks, I would say that being occasionally at a concert or at a sporting event, probably your hearing is going to be able to recover from that and it won't cause long-term damage. That said, we can't predict who is going to be more sensitive to situations like that and who isn't. And so I would strongly suggest that in those kinds of loud situations that you do wear hearing protection. They can be very, very inexpensive, from the little foam plugs that you get in the drugstore — I mean, they do have very, very fancy ear protection — but the foam plugs are fine.

John Horton:

Well, and it sounds like the earlier you start paying attention to that, you may be able to limit that damage from building up, and it just gives your ears a better shot as you get older. And as a bonus, you protect your brain.

Dr. Dylan Wint:

Absolutely. Protecting your hearing. Who doesn't want to have good hearing as they get older? But knowing that this can also reduce your risk of dementia by two to five times, I think should be an added bonus.

John Horton:

All right. Well, I may turn down the volume on the stereo now a little bit to keep the ears working right and keep the brain clicking along, too.

So Dr. Wint, I appreciate again you coming in, and you explained this so well, and it's really just valuable information that I think can help us all.

Dr. Dylan Wint:

Well, you're way too kind. It's great to see you and I enjoy talking with you.

John Horton:

Well, we'll have you back. Thanks again.

Dr. Dylan Wint:

Thank you.

John Horton:

Hearing loss may start in the ears, but over time, it can affect your brain health and even contribute to dementia. So don't ignore hearing issues as you age. Consider that sound advice that's worth listening to.

If you liked what you heard today, please hit the subscribe button and leave a comment to share your thoughts. Until next time, be well.

Speaker 3:

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