Diet & Eye Health: See the Connection with Nicole Bajic, MD & Phoebe Lin, MD, PhD

Podcast Transcript

John Horton:

Hello, and welcome to another Nutrition Essentials podcast, an offshoot of our popular Health Essentials show. I'm John Horton, your host. The next time you're eating dinner, take a good look at what's on your plate. What you see might determine how well you, well, see later in life. That's because your diet can have a pretty significant effect on your vision over the years. Consistently choosing foods packed with eye-friendly nutrients can help prevent age-related macular degeneration, glaucoma, and other issues. Choosing less than healthy foods, on the other hand, might leave you struggling to read those giant letters at the top of an eye exam chart. Today, we're going to focus on the connection between diet and eye health. As usual, registered dietitian Julia Zumpano is in studio to explain what food should be on our grocery list. To look deeper into our eyes, we're joined by two ophthalmologists from Cleveland Clinic's Cole Eye Institute. Julia, can you tell us a little more about our guests?

Julia Zumpano:

You bet, John. Our eyes may be small, but they are incredibly complex and intricate organs. Mechanisms in the front and back of the eye work in combination to allow you to see the world. Dr. Nicole Bajic dedicates much of her work to the anterior segment or front of the eye. Dr. Phoebe Lin, on the other hand, specializes in the posterior segment or back of the eye. Between them, we're pretty well covered as we look at links between eyesight and nutrition.

John Horton:

I think you're right, Julia, and by the time we're done chatting, folks should be able to see the importance of eating better to see better. Welcome to the podcast Dr. Bajic and Dr. Lin. We're always happy to get one of our fabulous doctors on the talk, so to get two at once to share their knowledge is just beyond amazing.

Nicole Bajic:

Thank you so much for having us. It's a pleasure to be here.

Phoebe Lin:

Thank you. It's wonderful to have this opportunity.

John Horton:

Well, we're so happy you're here. And I got to tell you, one of the things I love about doing Nutrition Essentials is exploring and better understanding how food affects every part of our bodies, even the areas that most of us don't connect to diet, and I think the eyes kind of fall in that category. I'm guessing most of us don't eat an apple, a doughnut, salad, or pepperoni pizza and wonder what it's going to mean for our retinas.

Nicole Bajic:

Absolutely. So regarding the importance of vision with how it affects the whole of the eye, one of the biggest risk factors that we see is aging. Why that comes into play is predominantly oxidative stress. And so oxidative stress, all that is is an imbalance between free radicals in the body and the antioxidants that help cancel them out. And so, when we have that imbalance, things can wear down faster, so these free radicals end up being a byproduct of just our normal cells in our body chugging along, doing everything that they should and just normal function and metabolism. But there are certain things that can trigger more free radicals than others, but we can also help counteract that by introducing more antioxidants in the body.

John Horton:

And that's where we get into the food choices and all the great items that we can put on our plate versus the not so great ones. Dr. Lin, do you find a lot of times that people are kind of surprised by the link with diet and vision?

Phoebe Lin:

Yes and no. I mean, a lot of patients ask about what they can do to help their own eye health, not necessarily talking about diet, but when it's brought up in lectures and reach out to patients overall, people do are very surprised about that link between gut health and dietary interventions and the eye because they seem to be so far away from each other and yet the whole body is so well-connected with the gut having to do a lot with how our body's immune system works. And so, it's actually, it's a very natural link to think that eye health is linked to your body's health and your gut health. But yeah, sometimes people are very surprised.

John Horton:

I'm really excited that we're going to be able to explore this a little bit in depth here today. So let's start breaking down how what we eat might play a role in our vision, and working front to back in the eye seems like the best approach. So Dr. Bajic, can you walk us through what's happening in the anterior segment or front of the eye and how diet can help or harm function?

Nicole Bajic:

Absolutely. So one of the biggest topics here is dry eye. So when we look at what helps contribute the most to good quality vision, so it's actually the air-tear film interface and the cornea that provide the most refractive power of the eye. And so, no disrespect to the retina because it's an essential part of the eye, but we wouldn't even be able to focus light onto the retina if we don't have that serving its function to focus light. So it's really important to have a good quality tear film. However, dry eye is a little bit complex. We do know that it seems to be related to inflammation. There's an inflammatory cascade that can predispose to it. However, there's so many different types of dry eye, and it's a very complex topic. And regarding what can help some and others, regarding the literature and how diet affects things, unfortunately, it's a little bit mixed.

For a long time, we were routinely recommending fish oil, omega-3 fatty acids. However, the National Eye Institute actually funded a study called the DREAM Study, and it was a multi-center randomized clinical trial, and they divided patients into two groups. So they had some take three grams of omega-3, so it was two grams of EPA and one of DHA, and then they had the other group take olive oil. And at a year out, they didn't find a statistically significant benefit to that in terms of improvement of dry eye. However, I think there's a lot more to the story, and I think what this might say is that maybe we're not better identifying the patients that might benefit from this because there is data in the literature to support the use of omega-3s with regards to something called digital eye strain or computer vision syndrome, which is so interesting.

John Horton:

Oh, wow. And that's a huge issue. Everybody, we're all staring at computer screens all day.

Nicole Bajic:

Right. And so, part of why it can cause significant symptoms and eye strain and dryness is because when you're focused on a screen, you're not blinking as often as you should. And it's thought that this might contribute to something called meibomian gland dysfunction, which circles back around to dry eye disease because we need those meibomian glands to deposit a little bit of oil into our tear film with every blink. And there is a thought, a theory that maybe if you're not using it regularly enough, that you lose the function. It's unclear if it's the chicken or the egg here, but the fish oil, we do see that there is a benefit in symptoms with regards to that.

I wonder if we're just not better identifying the people that might benefit most from fish oil. With regards to what I counsel my patients on this, fish oil has so many benefits in the rest of the body too, and as long as there's no contraindication from their primary care doctor, I think it's fine to try as long as we're doing all the other things that have been shown to help dry eye. So that's where I leave it with that.

John Horton:

You know, when you even talk about dry eye too, I'd imagine hydration becomes an issue with that. I mean, if you're not properly hydrated, would that also-

Nicole Bajic:

Absolutely. Absolutely. I mean, most of us is water, so we need that hydration to make all of the cells function exactly as they should, right? What's really interesting too though, there are other things that can contribute to dry eye like not sleeping enough, and it's thought that that boils down to inflammation, too. So when we talk about inflammation and anti-inflammatory diets, I think that there might be something there that we need to investigate more. Unfortunately, we're not at the point now where we have data that we can guide patients on, "This is the exact amount of this supplement you need to take to improve this or that," but I think taking a holistic approach to it as in, yes, we should all be introducing more antioxidants into our diet, anti-inflammatory type foods, omega-3s.

I suspect that there's also a synergistic effect too with everything, but there is support in the literature, but it's not so clear as to exactly how much of what we should be taking with that. I also want to segue to glaucoma for a bit because we do know, at least we have some data in the literature suggesting that antioxidants like bilberry extract or pine or even saffron has been shown to decrease intraocular pressure. Again though, we're not at the point now where we're actually recommending these to patients specifically, but it is something to note, and it's definitely a future area that we should explore more.

John Horton:

Well, what's nice with things like those, those are things that you can kind of add in slightly into your diet, and if it helps, great. If not, I don't think a little saffron... Adds a little flavor. I don't think it's going to do any harm. Of course, Julia would be the one to answer that.

Julia Zumpano:

No, I agree. I do think that Dr. Bajic, you made a great point of just a holistic approach and including overall omega-3s, and we know Americans are extremely deficient in omega-3 specifically when you look at the omega-3 to omega-6 ratio. I mean, we're eating 20 times more omega-6 than we are omega-3. And we know the positive benefits of omega-3, just in general from a whole body standpoint, can vastly decrease inflammation. And as extra virgin olive oil has been shown to be very antibacterial and very, very high in antioxidants, so very potent antioxidant. So that makes complete sense when it comes down to it that it affects your vision as it does your whole body, your cardiovascular system, and your whole system. So I think that's amazing. Just kind of pushing out that point that we just need to consume more omega-3s and more high antioxidant foods specifically healthy fats.

John Horton:

I got to say, Dr. Bajic, I love that you kind of threw down there a little bit that the front of the eye is the more important part. So now, we're going to get to the part where-

Nicole Bajic:

I'm not saying it's the most important. We all need all the parts to be working specifically, but it is true.

John Horton:

It's all in good fun. You know?

Nicole Bajic:

It is true-

John Horton:

A little battle of the eye here. I like it.

Nicole Bajic:

... that we need to respect the front of the eye because without it, it doesn't focus light onto the back.

John Horton:

So now, we're going to move to the back of the eye, the posterior segment, and Dr. Lin, that is your territory. So kind of give us a little rundown as to how diet can affect things back there.

Phoebe Lin:

Yes. So let's just go back. Again, the cornea is very important, and the retina is in the back part of the eye. It's neural tissue in the back part of the eye that changes light information into biochemical signals that then get transmitted to the brain and form vision. And so, the retina is obviously very important for vision, particularly the central retina which is called the macula. And the macula is that central part of the retina. It's responsible for your distance vision like when you drive and you look at signs, but also for your near vision like when you're reading, so it's a very important part of the retina. And one of the most common diseases that afflicts us in the U.S. and many people in the developed world is age-related macular degeneration. And so, age-related macular degeneration is one of the leading causes of irreversible blindness in the U.S. affecting 11 million people. It's a very important disease to know about. Most of us know people or family members and friends that have this disease. I treat this disease every day.

With the retina, the link between the gut health and diet and the eye at nAMD was shown by the, again, a National Eye Institute, National Institute of Health study called the AREDS2 study, where they showed that a combination of antioxidants containing vitamin C, vitamin E, as well as these carotenoids called lutein and zeaxanthin can slow the progression to the late form of macular degeneration where you lose central vision. And so, what that seems like and from a patient's perspective is you lose that ability to see the details of someone's face when you can still see, for instance, the outline of their head or hair. And so, it's a very, very consequential disease to have.

And so, these antioxidants were shown to slow progression to the late form. It doesn't happen in every person who takes these supplements, but it does slow things down in a percentage, up to 35% of individuals. Tagging onto the discussion on omega-3s, it was very interesting because that same group at the NIH, they looked at omega-3 supplementation for AMD, and actually, they didn't find that it was helpful, but what they did find in diet studies is that increased consumption of omega-3 high fish was effective in slowing down or decreasing your risk of developing late AMD.

John Horton:

So it's something else in there, maybe. Maybe not just the omega-3s.

Phoebe Lin:

Yes, or perhaps it's the bioavailability of the omega-3s through the actual source rather than supplementing at a high level. So it could be bioavailability, or maybe it's something else in the fish that goes a lot with it.

Nicole Bajic:

I just wanted to jump in. I think that this is a really... I'm so happy that Dr. Lin brought that up. It's such a smart point because actually, there's some controversy on omega-3s in ophthalmology regarding the source specifically. So there are some die-hard people that believe that it still is very beneficial for dry eye, but it has to be from a marine source. And so, some people are very particular about the brands that you buy, and they think it makes a big difference. I think that Dr. Lin brought up an excellent, very smart point.

Phoebe Lin:

Yeah, and that's what I try to drive home to my patients who do inquire about what they can do to help their eye health. So they're asking usually about supplements or diet. Supplements, it's hard to say. You know, AREDS2 have really great study, huge clinical trial that showed this potential benefit, again, not a cure and not necessarily effective for everyone, not going to reverse vision damage, but hopefully slowing things down, slowing down the actual loss of vision. And so, I try to tell them it's really more about the balance. And the other aspect is that the Mediterranean diet was actually studied very significantly, so both in Europe and then by the same group here in the U.S. by the NIH, and showed that a Mediterranean diet can also slow progression. And in fact, there's this type of advanced or late macular degeneration called dry advanced or late macular degeneration where you kind of have this slow progression of loss of vision from what's called geographic atrophy.

And that's when you lose the retinal pigment epithelial cells and the overlying photoreceptors, very important cells for function of the retina. So you lose these cells, and what these studies found were that certain types of Mediterranean diet can actually slow progression of geographic atrophy, so permanent vision loss, permanent central vision loss from loss of the retinal tissues that these cells can never regenerate. And so, if you can slow it down, you can't bring them back, but if you can slow down a loss of these cells with anything. And so, that's actually what I've been telling my patients, a Mediterranean diet, the AREDS2 supplements, and really focusing on the components of Mediterranean diet, such as leafy green vegetables, yellow and orange and red vegetables and whole fruit, as well as fish, omega-3s in the form of fish, over red meat. And red meat was actually a negative predictor of progression of advanced AMD.

John Horton:

Dr. Lin, what causes those cells to get damaged in the retina? Is that like a plaque buildup that we hear so much about in other areas?

Phoebe Lin:

Yeah, it's very interesting that you bring that up. Very good point here because there is overlap between macular degeneration and cardiovascular disease, and we often actually have this kind of combined research literature between the two fields. And that's because in atherosclerotic plaques, which are known to increase risk of cardiovascular morbidity such as stroke and heart attack, those plaques contain oxidized lipids and inflammatory proteins like complement and other inflammatory proteins as well, and those are actually very similar to the deposits that are found under the retina that actually herald macular degeneration. They're called drusen. So we call them drusen. That's the medical term for these deposits under the retina that result in damage to those photoreceptors and the retinal pigment epithelial cells that then results in the vision loss. And so again, there's that overlap, so you can imagine cardiovascular health probably does in some... There's a large overlap in terms of eye health for macular degeneration.

John Horton:

That's just such an amazing connection there because you think of your heart pretty clearly with this plaque buildup and all that, but you don't think of that as something you need to worry about with your eye. But I'd imagine that that gunky stuff that we worry about with our heart, when it gets up into your eye and the tiny, tiny blood vessels up there, it probably can really do some damage.

Phoebe Lin:

Right. They're very tiny, so they're on the level of microns in width, these deposits, but for some reason, they do get deposited in the macula, the essential part of the retina, and then over time, they can inflict damage. And when you have loss of the cells, it's unfortunately irreversible. So it's all about prevention of progression of disease, and that's where the interventions that we're talking about today come into play.

John Horton:

Well, and I love that idea of prevention because obviously, age-related macular degeneration, as you get older, it's going to happen. But it sounds like if you make some wise choices in your diet, you can maybe slow that process a little bit, which kind of brings us now to where we're going to kind of let Julia shine here, and let's start talking food a little bit. I think if we can start with the things you eat that might slowly steal your vision or accelerate that degeneration, so help us out here, Julia. What should we be avoiding or limiting to keep our peepers in tip-top shape?

Julia Zumpano:

Perfect. Yeah, Dr. Lin mentioned a couple things, and she was spot-on. So red meats and processed meats are definitely things we should avoid. High-sodium foods, so highly processed box-prepared meals or canned foods, anything really in a box or bag that's highly processed. Snack food can have high amounts of sodium. That can affect the retinopathy and blood vessel damage in your eyes. We know simple sugars or simple carbs, they're also known as, and those are all those foods that fall into that white category so like white bread, white rice, white pasta, white crackers, bakery items like bagels and doughnuts and croissants and sweets and desserts. We consume a large, large amount of this category of foods in the standard American diet, so we know that it's a culprit for a lot of things like obesity and high triglycerides and diabetes and metabolic syndrome, but you know what it does? It is connected to age-related macular degeneration. So we really want to take another step and look at it from the whole body, not just what we actually visually see.

Our vision is highly affected by what we eat as we're seeing. You know, fried and fatty foods, of course, we want to avoid. I mentioned sugary foods. Alcohol has even been shown to be connected to cataracts, so high levels and high amounts of alcohol, so all of those foods... No surprises here. All the foods we normally want to avoid for overall disease prevention, all that applies here, too. And as Dr. Lin mentioned, the phenomenal Mediterranean diet has been vastly studied and shown to really help support overall full body health.

John Horton:

So Julia, since we always try to emphasize the positives, what foods should we load up on because they can help protect your eyes?

Julia Zumpano:

So certainly, the Mediterranean diet, which is very rich in fruits and vegetables, which are packed in antioxidants, so color is key there, so a variety of different colors, really trying to add variety, too. So I always say, "You know what? Most people kind of stick to the same fruits and vegetables in their grocery list." I challenge people to get a new fruit and vegetable every time they go, so they add a little bit more variety each time.

John Horton:

Eat the rainbow. Isn't that always the advice?

Julia Zumpano:

Eat the rainbow. Absolutely. So whole grains, so limiting those refined grains, so things like... Grains really though, not grain products, so I do minimize things like whole grain bread even and try to challenge clients and patients to eat things like quinoa and barley and oats and brown or wild rice, so just maximizing on the availability of different grains. Legumes are phenomenal source of protein, fiber, antioxidants, so legumes include dried beans, lentils. And then, nuts and seeds, they provide a phenomenal source of plant-based fats, monounsaturated fats, and specific seeds like chia seeds and flaxseeds can provide the plant-based source of omega-3 called alpha-linolenic acid, and that's very beneficial. Things like walnuts also have that alpha-linolenic acid, the plant-based source of omega-3. Almonds, all varieties of different nuts and seeds are phenomenal and of course, the extra virgin olive oil, which has been shown to be very potent antioxidants and high in those healthy monounsaturated fats.

John Horton:

While we're on the topic of the omega-3s, because we were talking about those a lot earlier, and you just mentioned a bunch of plant-based sources of omega-3s and-

Julia Zumpano:

Yes. And of course, the fish, so things like salmon, herring, tuna, mackerel, those are great sources of omega-3.

John Horton:

But it sounds like earlier we were talking that maybe you got more benefit out of the fish?

Phoebe Lin:

I mean, it's probably more like natural sources through the food rather than the supplementation, but that's what I was kind of harping rather than fish itself. But I mean, that study was saying probably through the fish, it was important, but I'm sure that plant-based sources would be actually beneficial over a supplement as well.

Nicole Bajic:

Also, when it comes to supplements, it's not regulated like medications are in the United States, and so you aren't always getting what you think you're getting. And so, I think that's why physicians are typically going to be a little bit more cautious when it comes to recommending a supplement. But food is medicine, and I would encourage anyone to focus on their diet first and foremost. And supplementation could be considered, again, as a supplement if needed. If there is a deficiency in someone's diet, then that could be a good reason to use it, and maybe for some of these other things here, it could be considered. But diet, I think, is the most important to focus on here.

Julia Zumpano:

I think one important point that we would all agree on is if you're taking a supplement, sometimes people assume, "Oh, well I'm covered. I can just eat whatever I want." And I think the holistic approach of the diet and including fish as what's recommended in the Mediterranean diet about three days a week, well, you're not eating other less desirable sources of protein. So you're eating fish, but maybe not eating red meat or processed meat, so it's the holistic approach. If you're eating more whole foods, you're not including so many of those processed foods or refined carbohydrates or unhealthy oils and saturated fatty foods that can wreak havoc on our whole system. So if you really heavily focus on diet and look at the components of the Mediterranean diet, there's really no room for those unhealthier food choices, which I hate to call them unhealthy. They just don't serve our body as well. They can be included in moderation, but if you're just heavily focused on getting all of those nutrient-dense foods in, there's less room for those.

John Horton:

Earlier, I think Dr. Lin mentioned two very specific antioxidants, Julia. She mentioned a lutein, and the other one, which I can never say, was zea-

Julia Zumpano:

Zeaxanthin. Yeah.

John Horton:

Zeaxanthin. That seems like the ultimate scrabble word. You could get big time points on that one.

Julia Zumpano:

Yeah.

John Horton:

Tell us where do we find those because I've never seen those just on the shelf. So what food can we get those in?

Julia Zumpano:

Definitely can't find them on a shelf, but you can find them in food. Again, just to reiterate, they are the only dietary carotenoids that accumulate in the retina, specifically macula, so they are called macular pigments. The key sources of lutein and zeaxanthin include things like kale, savoy cabbage, spinach, broccoli, peas, parsley, corn, and egg yolks are an excellent source. So again, really plant-based, heavily plant-based foods, a lot of color, a lot of greens, a lot of green and yellow foods, the egg yolks specifically as well.

John Horton:

In talking colors too, I thought I always heard orange is good for your eyes. So what's the magic in that color?

Julia Zumpano:

So orange is responsible for a carotenoid. So we have a lot of carotenoids have that orangey flavor or orangey color, and they are very healthy for the eyes. So we obviously know things like carrots and yellow squash, corn, and all those yellowy orangey foods are very helpful.

John Horton:

Just in case people are looking to know, what do carotenoids do specifically in your eye?

Phoebe Lin:

They form macular pigment, so again, the center part of the retina. So your photoreceptors, they have this cycle where they're producing a lot of waste, and these macular pigments actually reduce the photooxidative damage to the retinal pigment epithelium, which is the layer of cells that support.

John Horton:

So it's like taking the film off.

Phoebe Lin:

Well, it's like... Yeah, these are cells that are very active, as you can imagine. You use your eyes even when they're closed, right? But yeah, so what it helps is it prevents the photooxidative damage to the supporting layer of the cells underneath the photoreceptors. And I would say in terms of the beta-carotene, an interesting story is that, I don't know if you know, is that it is probably healthy to get them through the foods. When they were used in the AREDS supplement, the original supplement, to try to slow down macular degeneration, what they found was that, yeah, it was effective, but actually at those high doses, it was found to increase the risk of lung cancer in former and current smokers. And so, the formulation was switched from beta-carotene containing to the lutein and zeaxanthin that it is now in AREDS2. And so, just wanted to point out that if you overdo any particular thing, such as going crazy on carrots only or beta-carotene only at very high doses, there are consequences. So it's really the balance that you want to look at.

John Horton:

Moderation is always... I've heard Julia say that. I can't even tell you how many times. So it seems to be the key with everything with diet.

Julia Zumpano:

One thing to note too, beta-carotene rich foods are not only in yellow and orangey foods. Of course, we think of pumpkin and sweet potato, squash, but they're also in greens, as we've mentioned, so they're very abundant in things like spinach and collard greens and kale.

John Horton:

Well, while we're talking about beneficial foods, I want to take a little detour and shift our focus to some research that's being done by Dr. Lin and the possibility that pectins and a high fiber diet may play an even larger role in eye health. So Dr. Lin, can you share what you found so far?

Phoebe Lin:

Yes, I'd love to. Thank you, John. In addition to being a retina expert, I'm also a uveitis specialist, and I work on inflammatory diseases of the eye. So in that role, I've been investigating the role of the gut microbiome, so the commensal microorganisms that reside normally in our body, particularly the gastrointestinal tract, and how they interface with gut immunity, but also systemic and thus ocular immunity. Again, everything's connected. And so, what I found in our lab was that a diet that's high in pectin is actually protective against autoimmune uveitis or inflammation of the inner part of the eye. And the reason we started to look at high pectin diet was because we had actually first to see that the microbiota, the microbes that reside in the gut, are very influential in autoimmune disease of the eye. And then, we found that a short-chain fatty acid called propionate, which is actually metabolite that's produced by gut bacteria when you consume certain types of high fiber diet, we found that that metabolite propionate, a short-chain fatty acid, was protective against severe autoimmune uveitis in mice.

And so then, when we looked at different high fiber diets, we actually found that the high pectin diet was especially influential, especially protective in these mice. And then, we found it was actually through the way that these, again, metabolites of the bacteria in our gut due to what we eat and how they actually regulate the immune system versus specific immune cell types that are promoted and regulate the immune system when these short-chain fatty acids are produced by the gut bacteria and hence the influence of this high pectin diet. And so, how does that link into other age-related diseases and other diseases, which honestly all have a lot in common, the inflammation pathway? And what we think and actually now, some of my research is extending into macular degeneration because the gut bacteria are so influential in our immune system and the types of things that they produce that most likely we're going to be able to modify those gut bacteria and even to their benefit and to our benefit by the diet that we eat. But macular degeneration will have that link as well, and our lab has begun to explore that.

John Horton:

That's just amazing the way that works.

Julia Zumpano:

Yeah, that's fascinating.

John Horton:

As far as pectins, Julia, can you walk us through some of the foods that you can find pectins in?

Julia Zumpano:

Yeah, sure. So pectin is actually used as a stabilizer or preservatives in things like jams, jellies, frozen food, and candy. But that's not the way we want to get pectin in. I'm just-

John Horton:

No, I was going to say I was going to fall out of my chair if you were going to tell it to all to eat more candy.

Julia Zumpano:

No, I just wanted to put a disclaimer out there because you will read it in some of those ingredients, and I don't want us to seek out those ingredients that way. The best way to obtain pectin, which is not on a label because they're whole foods and they don't have labels, are things like fruits, apples, apricots, cranberries, citrus fruits, grapes, bananas, and then some legumes, beans, and carrots. So there's all a lot of great whole foods that have pectin, again, fruits and vegetables. You know, these foods are also high in antioxidants, so you're going to get more than one benefit and fiber, so three benefits.

John Horton:

Dr. Lin, this research is just amazing. And it seems like there's so much opportunity there to really help people out.

Phoebe Lin:

Yeah, I mean, I agree. Whether it be through dietary changes, which again, it might be related to the gut health that you start out with, how you can absorb these nutrients that you need for essential functions of the eye, so either through that or through other methods that we've learned through the gut microbiome studies, which is to kind of target the natural metabolites that are beneficial for our immune system. And so, there's various ways that the research will help eye health.

Nicole Bajic:

Yeah.

Julia Zumpano:

That's amazing.

Nicole Bajic:

I don't like apples, but after I heard Dr. Lin talk about her research, I started eating them with the skins on. All I know is you need to eat the skin.

Phoebe Lin:

With the skins on. Just wash all those chemicals off, but yeah, right. It's tough to know what to eat and what not to eat, and I think it's really the balance that makes a difference. And so, in terms of, again, increasing those varied sources with the multitudes of benefits that Julia mentioned, so the fact that you're getting a beneficial fiber and you're getting antioxidants and you're getting, I think you mentioned other, well, fiber in general, other sources of fiber, and then just the sources that have overlapped with omega-3s. There's all kinds of literature that they're just all very interlinked in terms of helping your gut bacteria produce what's more available to your body to use them for your eye health, but other parts of the body as well.

Julia Zumpano:

Well, right. Like you mentioned, Dr. Lin, fibrous-rich foods are prebiotics. So prebiotics are found in fiber, and prebiotics are what feed the probiotics, the healthy gut bacteria. So your fiber is really essential for a healthy gut and variety.

Phoebe Lin:

Yes, yes, exactly. Yeah, it's quite amazing that these products of the gut bacteria from your diet actually are so influential in your immune system, and they're actually not produced by our own host cells. So for instance, propionate is a short-chain fatty acid that's very important for health and inflammation and actually is not produced by our own cells. It's produced by gut bacteria and how it acts on the diet that we eat, the fiber. So these are things we actually can't do by ourselves, but we can influence it by the diet that we take.

John Horton:

It's so amazing with all of these connections, and I'm really just astounded. Everything we've talked about today, our first couple of Nutrition Essentials podcasts that focused on the heart, the gut, and now the eyes, and they're all interconnected. I can't believe how combined everything is, so it just really goes to show how these things are tied together.

Nicole Bajic:

Yeah. I mean-

Julia Zumpano:

It's very fascinating.

Phoebe Lin:

Yeah.

Nicole Bajic:

... I think that the important thing we hear... We're almost like a broken record with physicians, what they recommend, "Get your exercise, eat a healthy well-balanced diet, don't smoke," but it's true. All those things help promote wellness. It decreases inflammation, decreases oxidative stress, and we keep talking about it because it helps. It really does. It makes a difference.

John Horton:

It makes a difference. Yeah, yeah. So from everything that we've been talking about, the connection between diet and eye health seems pretty clear. So Dr. Bajic and Dr. Lin, how often do you talk with your patients about the importance of their food choices?

Nicole Bajic:

So I'll defer to Dr. Lin regarding the retina because one, it's the most well-studied regarding nutrition and supplements in terms of eye health. But for me, while I do take care of some macular degeneration patients and will recommend the supplements she discussed, I do recommend in general that we should all be eating a healthy, well-balanced diet. So when patients bring it up, "What else can I do? I'm doing XY and Z," that's my bonus. And maybe stop smoking if they're smoking. So eat the well-balanced diet, make sure you're getting your dark, leafy greens. For some, I recommend omega-3s if indicated, and that's it.

Phoebe Lin:

Yeah, I mean, every single day that I'm in the clinic, I discuss diet with at least one, but usually up to five, I guess, patients who are new and want to know a little bit more about what they can do to improve their eye health. So I'm talking about the AREDS 2 supplement, the Mediterranean diet, what is the Mediterranean diet. My uveitis patients also ask. I have less clinical trial data for them, but hopefully, that would be forthcoming in future studies. And so, I talk about diet with my uveitis patients as well because that's so much more evidently linked to inflammation. And so, people know about this a little bit more now, and they want to know what they can do.

So I pretty much talk about it every single day with my patients. And the limitation is that it's hard to do clinical trials with diet studies and with supplementation, and so we just have a paucity of that to really guide our patients. And also, we don't have a nutritionist like Julia in the clinic with us. That would be ultimately something very helpful for every single clinic, but especially the eye clinic. We don't have that, so it's limited to short blurbs, but I definitely talk about it every single day at the clinic.

John Horton:

Well, let's work on giving people some tips now. And so, this is kind of a question for all of you. If people after listening to this want to make dietary changes to help their eyes and don't know where to start, what should they do? Maybe Julia, why don't you get us started here?

Julia Zumpano:

Sure. So one simple thing I always have patients start with is taking a look at how many fruits and vegetables they're eating, something simple. So trying to get in a fruit and vegetable every time you eat. If you can do fruit and vegetable with breakfast, lunch, and dinner, that's great. If you're very far from that, I try to get in one fruit and one vegetable in a day. So just I'm trying to increase slowly their intake of fruits and vegetables, and I always recommend start with what you like. You don't need to start with something new. Just start with your favorite fruit and your favorite vegetable, eat it consistently for a couple weeks, and then next time you go to the grocery store, start to vary that. Add something new in. Maybe add another one in and start to increase. We know we need seven to nine servings of fruits and vegetables a day. I think close to 80% of Americans are probably not getting that. So that is usually where I start because of the antioxidants in those foods, because of the vitamins, the minerals, and the fiber. That's generally my starting point.

John Horton:

Great advice. Dr. Bajic, Dr. Lin, anything to add to that?

Phoebe Lin:

I thought that was great practical advice. I encourage when, for instance, friends or family members ask how they should approach this with their doctor, I just say, "Go ahead and ask, 'What can I do? What are some things that I can do to change my diet, or what can I take to do on my own besides I guess traditional medication or therapy that can help myself with my eye health?'" And I just say, "You go ahead and bring that up to your doctor." In terms of how I talk to my patients about it, typically, I know I have a little handout. I say, "Please seek out a nutritionist if you feel like you need help with the elements of what this means." Typically, I'll just kind of summarize the AREDS 2 for macular degeneration and the Mediterranean diet for, really, all patients because, sorry, if they're asking, then typically, they're kind of at a state where maybe they want to, they're motivated to make a change in their lifestyle.

I do oftentimes get patients who say, "Well, I hate fish," or "I don't eat vegetables. I'm just a meat eater." And so, that's when I get a little bit stuck where a nutritionist would probably help, being able to give them practical advice on what they can make one thing at a time, a change that they can make one thing at a time and still be very happy with their diet when they make that change. But most people, I find are very motivated and also are inquiring and maybe just don't know how. And so, just getting the conversation started, I think, is actually a big thing.

John Horton:

It can be pretty... I mean, you got Dr. Bajic to start eating apples.

Nicole Bajic:

Yeah.

John Horton:

So there's already movement that we're seeing here.

Phoebe Lin:

That's great. That's great.

John Horton:

We get great advice all the way around, and better yet, it seems like a lot of these are dietary changes that people can make pretty easily. So I feel like we're in a great spot with our conversation as we kind of come to a close here. But before we say our goodbyes, does anyone have something else they'd like to add?

Julia Zumpano:

I'd like to just note that thank you, Dr. Lin, for highlighting the role a dietitian can play. Because I do think oftentimes, if you do feel lost in your journey on how to eat healthier, a dietitian can be a great way to get you on the right track. We have a multitude of resources. We can develop plans for you. We can give you grocery lists. We can help you guide you through step-by-step on how to slowly improve your diet. If you have a family involved, we certainly can include there. If you're single, we can help there. So we really have so many great resources, and we have the time. That's our main focus, is to help you eat healthier based on where you are at that moment, so we meet you where you're at. We give you the resources you need. Whatever concerns you might have, whether they may be taste or financial, we have definitely means to help overcome challenges in that area. So if you have the means and ability to meet with a dietitian, I would highly recommend it.

Nicole Bajic:

So one thing I'd love to add is that we can't find something if we're not looking for it. So we really recommend that every patient come in for their annual eye exams because so often, I see patients come in, they are asymptomatic, they think their vision's great, and then we find something that we really need to take a closer eye and keep a closer eye on. So make sure you're coming in for your annual appointment, so we can check everything out and make sure that you're well taken care of. Dr. Lin, have anything to add from the retina perspective?

Phoebe Lin:

Yeah, I would definitely encourage folks to do their annual eye exam. Particularly if they have a family history of eye disease, they really should pay attention. And if they have visual symptoms, make sure they're prompt and very on top of getting in to see the right specialist. Oftentimes, just like Dr. Bajic, I'll see patients who come in very late in the disease process, and it's hard to kind of reverse course, especially with retinal disease. So again, prevention is the key, in which case, we have to rely on all of the listeners and patients to pay attention to their visual symptoms and come in promptly and maybe even get screened on a regular basis even if they don't notice symptoms.

Nicole Bajic:

We must respect the retina. So just to highlight, I don't want there any confusion.

John Horton:

We don't want any worrying over which part of the eyes is more important.

Nicole Bajic:

The retina's like-

John Horton:

It's all important.

Nicole Bajic:

But the retina is like the motherboard, right? It's like the motherboard of the computer. And so, if that's not working, we can't replace it, so very important to make sure it's taken care of, too.

Phoebe Lin:

Yeah, that's a better analogy than the camera and the film thing. Nobody knows what film is anymore, so I like that, the motherboard.

John Horton:

That's a great note to end on. We can continue our front of the eye, back of the eye debate maybe at some other time.

Nicole Bajic:

I like that.

John Horton:

But thank you so much everyone for coming in and spending some time with us.

Phoebe Lin:

Great. Thank you all.

Nicole Bajic:

Thank you.

John Horton:

Julia, that was just an amazing conversation. I just cannot believe the links between diet and eye health.

Julia Zumpano:

I couldn't agree more, John. I actually learned a ton today, a lot more that I didn't know. I knew nutrition helped the whole body, but the intricate details on how it helps the eye, front and back, I was amazed. And it's really a great way to just reinforce overall healthy nutrition choices. And it's really a whole top to bottom approach. It really helps your whole system.

John Horton:

Well, and I feel like we even got a little extra in the research that Dr. Lin is doing. It's like a little bit we're ahead of the game here.

Julia Zumpano:

Absolutely. The importance of gut health and pectin in foods, that was fascinating. And the benefit of that is all of those pectin-rich foods and gut healthy foods are overall healthy for antioxidant-rich and so many other great nutrients that it's all intertwined and interconnected, and it's great to see that in so many different ways.

John Horton:

Well, I think I'm going to join Dr. Bajic now and make sure I'm grabbing an apple a day. If you liked what you heard today, please hit the subscribe button and leave a comment to share your thoughts. Until next time, eat well.

Speaker 1:

Thank you for listening to Health Essentials, brought to you by Cleveland Clinic and Cleveland Clinic Children's. To make sure you never miss an episode, subscribe wherever you get your podcasts or visit clevelandclinic.org/hepodcast. This podcast is for informational purposes only and is not intended to replace the advice of your own physician.