Tom (00:01.902)
A recent study in the American journal Lifestyle Medicine looked at the protective effect on hearing loss due to a higher intake.
Tom (00:14.222)
A recent study in the American Journal of Lifestyle Medicine looked at the protective effect of certain vitamins on hearing loss. And these vitamins included things like carotenoids, vitamin A, C, E, and folate present in these participants' diets. Now this was a systematic review with a meta -analysis aimed to verify the occurrence of a protective effect.
What that means is they took several studies, combined them together and using statistics, they came up with the results after combining all these studies. And the study is called Effectiveness in Preventing Hearing Loss Meta Analysis of Dietary Consumption Studies. And this is done actually in Brazil. The lead doctor was Laura Faustino Goncalves. And I'm just gonna go into a little bit,
a little bit of what they looked at. So they looked at the odds ratio, which is a measure of the association between an exposure and an outcome. And so you're exposed to these vitamins, what is the outcome of that? And they also looked at the hazards ratio, which is a measure of how often a particular event happens in one group compared to the other. So let's say you,
They compared you who ate lots of vitamins versus these other people who ate less or almost no vitamins, right? Now, how often do you develop hearing loss? Is it, you know, one in 10 in your group with a high vitamin intake, did they develop hearing loss, right? And hearing loss affects 466 million worldwide. And it's due to things like environmental noise, like machinery, trains, airplanes,
as well as things like ototoxic drugs, like amino glycosides. And interestingly, amino glycosides can be used to treat certain ear infections. So that's why you have to be careful and make sure that the eardrum is intact before using these medications, which work effectively, like really well. But if you have a whole new eardrum, they can destroy,
Tom (02:42.632)
part of that nerve in her ear and certain other organs in the ear. There's also a cisplatin, which is a chemotherapeutic drug. And what this does or what these things do is they decrease your ability to detect high frequency sounds. And so what this does also is now it affects your speech discrimination, meaning you can't.
really tell a difference in these words that people are saying, as well as your recognition of certain words and your understanding of the conversation in general. Now, there is a theory called the free radical aging theory. And this postulates or says that aging results from increased or accumulated oxidative damage caused by free radicals.
Now free radicals are able to cause certain reactions to occur. So what they do is they either can join onto a molecule and this causes damage to that molecule or causes it to be non -functional. So like our DNA, they can cleave our DNA and then our DNA doesn't work anymore. It can't produce.
or repair the organs that we use, like an inner ear organ called the organ of corti. Now, certain foods like fruits and vegetables have antioxidants in their composition. And these include things like vitamin C, E, and A, chlorophyll, flavonoids, carotenoids, curcumin, and there's like a whole list of others. Now, what happens in...
hearing loss is that the free radicals damage the inner ear as well as the mitochondria in there. And that inner ear is essentially the neuron that's connected to your brain that helps to process hearing. So, or process sounds. And this meta -analysis involved five studies and there was an estimated 100 ,549 participants.
Tom (05:02.394)
which were included in this quantitative synthesis. And they had some pretty interesting findings. Those people with high intake of beta -carotene and magnesium had better hearing thresholds as well as better speech recognition. Vitamins C and magnesium together.
significantly reduced hearing thresholds at high frequencies. And what this means is that you can detect these higher frequencies a lot better than someone who didn't include these vitamins and minerals in their diet. And there's a relationship between retinol or vitamin A in hearing. And they postulate that the retinol has a high concentration in the inner ear.
and retinoic acid, which comes from vitamin A or retinol, is used to contribute to the development of an organ of corti. And this organ of corti is essentially the beginning of the main neuron, which helps to process the sound in your ear. Now, interesting consumption of what's called riboflavin.
was significantly associated with better hearing thresholds. So these two vitamins, retinol and riboflavin, are found mainly in animal foods like milk, cheese, and eggs. Now, kind of interesting, what they found after combining the studies was that vitamin C did not have an association.
between higher vitamin intake and lower risk of hearing loss. Now some studies did show that there was a positive relationship, but this was counterbalanced by the other study that showed a negative relationship. So very, very interesting. And this is kind of what you get when you combine studies together. Now vitamin A and folate together had no...
Tom (07:24.236)
apparent protective effect, but retinol, and like I said before, and riboflavin was associated with better hearing thresholds. So what does this all mean, right? Well, overall, your dietary intake of vitamins and antioxidants is inversely associated, meaning it causes the opposite to occur.
So it's inversely associated with a risk of developing hearing loss. And individuals with a higher intake of antioxidants may have better hearing thresholds, especially with the intake of beta -carotene. And what are some study limitations? It's always important to point these out, right? Well, one is the diet recall. So,
When patients are asked, hey, what did you do 24 hours ago? What did you eat? It can be hard for them to recall what they actually ate. They may say the wrong thing and then that causes the study results to not be accurate. Now there's also like a hearing loss questionnaire, meaning it may ask you like, hey, do you have trouble hearing people in conversation?
Maybe when they're facing away from you. And you can answer yes, but maybe that occurred in a loud coffee shop and you're just kind of saying yes anyways, because that's how you remember it. Then there's the ability of the hearing test technician to actually do the test. So how well could they perform that test and then,
the different ways it was conducted. So maybe they tested more frequencies and the person had a little more warmup time, so they were ready to respond and they were primed more so that they responded better. So those were some limitations of the study itself, but I think overall, the whole idea is that, hey, if you consume a variety of fruits and vegetables,
Tom (09:51.038)
ones that don't bother you, and there are some that can bother certain people, you have a greater chance of being protected against hearing loss as you get older. So I hope that was somewhat informative and you were able to gather some good ideas from that. If you have any questions, definitely let me know. And if you like this podcast,
Leaving a review is always appreciated. But I do hope that you have a happy and healthy day and I'll talk to you next time.