The #1 Dementia risk factor nobody talks about, and what to do

**Jonathan** (0:00)
Welcome to ZOE Science and Nutrition, where world leading scientists explain how their research can improve your health.
Did you know there's an invisible disability that affects one in five people globally, that increases the risk of developing dementia by 500% and has few treatment options and no cure? I'm talking about hearing loss. An astonishing half a billion people have hearing loss that impacts their ability to communicate and connect with others. And even more worrying, hearing loss cases are increasing fast, especially in younger people. For many, hearing aids and cochlear implants can be life-changing, but they can't help everyone. Hope, however, is on the horizon. Scientists around the world have been working tirelessly to develop new treatments for hearing loss. Leading the charge is Dr. Marcelo Rivolta, a professor of sensory stem cell biology at Sheffield University. He's on the cusp of a major breakthrough that could mean hearing loss becomes a thing of the past. By the end of today's episode, you'll understand the latest treatments, what the future of hearing loss looks like, and how looking after your hearing could reduce your risk of dementia. Marcelo, thank you so much for joining me today.

**Marcelo Rivolta** (1:33)
Thank you.

**Jonathan** (1:34)
So we have a tradition here at ZOE where we always start with a quick fire round of questions from our listeners. And we have these rules that are designed to be really hard for professors.

**Rich** (1:44)
Right.

**Jonathan** (1:45)
And that is because the rule is you have to say yes or no, or a one-sentence answer if you have to. Are you willing to give it a go?

**Rich** (1:54)
Yep.

**Marcelo Rivolta** (1:55)
Let's do it.

**Rich** (1:55)
All right.

**Jonathan** (1:57)
Does hearing loss only really affect older adults?

**Marcelo Rivolta** (2:01)
No.

**Jonathan** (2:02)
Are more of us facing hearing loss than ever before?

**Marcelo Rivolta** (2:06)
Yes.

**Jonathan** (2:07)
Do people with hearing loss face an increased risk of dementia?

**Marcelo Rivolta** (2:12)
Yes, that is true.

**Jonathan** (2:14)
Can hearing aids help everybody with hearing loss?

**Marcelo Rivolta** (2:18)
No, unfortunately not.

**Jonathan** (2:20)
And finally, is a cure for hearing loss possible?

**Marcelo Rivolta** (2:25)
We think it is, and we are developing something which we think could change the landscape.

**Jonathan** (2:30)
My podcast producer Rich has actually talked to me about how in his teenage years, he was running these underground raves, and that means now in his thirties, his hearing is actually damaged. And in my case, I remember the time that my son, aged about 11, so it's about seven years ago, joyfully showed me this app on his phone that played these high-pitched noises. And I discovered that not only I couldn't hear lots of noises that he said he could, but really depressingly, there were lots of noises my wife could hear that I couldn't hear. And I think since then, I've really noticed that in noisy restaurants, I can really struggle to hear people who are further away from me. I'm aware that I'm not quite as good as hearing as I was when I was 20 So then when you're telling me that hearing loss is becoming more common, I think that's very worrying. Why are we seeing this rise in cases?

**Marcelo Rivolta** (3:24)
One of the reasons why it's becoming more common is because as a population, we are aging. It's more common to have older people and we live longer. One of the key factors that influence hearing loss is aging. As you said, that loss of the very high pitch sounds that you tend to have from middle age onwards, is just the opening of the door of more substantial hearing loss that will happen later in life.
As a population, we are growing older, and it's more common to have older people, so that's one of the factors. But the other factor is we live in a noisier, in a more loud world. We have a lot of noise exposure, the use of headphones is prevalent, and sometimes we don't tend to respect the kind of the volume controls that most of the devices have, and the exposure to loud noises is really impacting the incidence of hearing loss in general.

**Jonathan** (4:22)
And I'm interested that you already started talking about headphones. Are headphones safe or am I inevitably leading the path to becoming deaf if I'm using them?

**Marcelo Rivolta** (4:34)
I think the headphones, the way that they are built, they have safety limits. There's strong advice built by the manufacturers of what is safe and what is unsafe. But we tend to do, particularly the younger age groups tend to use it beyond those safety limits because get a more thrill of listening to very loud music. And also when we go to gigs and music festivals, we are exposed to very, very loud levels of noise and sound that tend to be a bit unsafe.