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The Younger Skin Diet: Rajani Katta, MD, on PYP 428

I think that having healthy, attractive skin is probably a lot more motivating to most people than a healthy heart, or liver, or pancreas. I mean, those organs are great and all, and important, but they're so, well, hidden.

Out of sight and out of mind, at least until they malfunction.

Skin, on the other hand – it's staring us in the face all day long. Hell, it is our face. And when our skin feels dry and paper, or sags, or gets spots and wrinkles, we don't like that one bit.

So the good news and the bad news is – our lifestyles can significantly affect the health of our skin. Diet, coping with stress, sleep quality – all these can fast forward aging, or slow it down, depending on our choices.

Rajani Katta, MD, is a dermatologist and professor at the Baylor College of Medicine, and the author of Glow: The Dermatologist's Guide to a Whole Foods Younger Skin Diet. On today's podcast, we talk about the evidence connecting diet and lifestyle to radiant, healthy skin.

When I was a kid, everyone knew that too much chocolate caused acne.

Until science said that was a myth, so we stopped believing it.

Except that I still knew that I could dial my pimples up or down, depending on how clean I ate.

So it was good to discover from Dr Katta that those studies on sugar and acne were poorly done, with a small sample size, very little difference between experimental and control protocols, and short-term outcome measures.

I mean, even as we were told that food didn't affect skin, we were also told all about allergic reactions of the skin to trigger foods. So which was true: link, or no link?

In our conversation, I ask lots of really basic questions about the skin, starting with “What is skin?” and “What's it for?” (Basic, right?) And then we dive into the evidence for a certain dietary pattern (whole food, plant-centric, anyone?) to promote healthy skin.

We explore the pathways of damage and premature aging, and discover why high blood sugar and cooked red meat are so damaging to skin.

And even come across evidence that certain foods can render our skin sun-resistant, allowing us to spend more time outdoors without burning.

Dr Katta shares her analysis of claims that some supplements can improve skin health, such as collagen. Spoiler alert – eat plants, avoid red meat and processed carbs, and save your money.

And in perhaps her most memorable line, she reminds us that if we eat a lot of bacon, we'll probably end up looking like bacon.

Read the full transcript here

Dr. Rajani Katta, welcome to the Plant Yourself podcast.

Oh, I'm so excited to be here today with you.

Let's talk about skin, shall we?

Oh, yes, one of my favorite topics.

Oh, good, good. Because, I mean, I've been thinking, you know, I've been thinking for many years, like, how do we reach people with a message of eating healthier? And, you know, like we know that just talking to people about being healthier doesn't always motivate. So we talk about weight loss and people can get very exhausted about weight loss.

Lately, I've been working with Team Sherzai to put together some some courses on preventing Alzheimer's, which a lot of people find in, you know, inspiring and motivating. But when I saw your work and you have this book called Glow, but the dermatologists guide to a Whole Foods younger skin diet.

I'm like, that's the ticket. Like, everybody cares about how their skin looks?

Yeah, I think so. Yeah. It's very immediate, isn't it? As opposed to hypertension, maybe, you know, your skin kind of speaks to you on a daily basis, I think. Yeah.

I mean, I was just thinking like I was going to go eat something. And I have a gamut of, like, you know, choices and standards. And none of them is terrible that some of them aren't great. But if I think about like heart disease or, you know, I run, so I may not gain that much weight, but I'm thinking like, oh, I don't want my skin to show people what I eat, like tomorrow.

It really helps. Like, reading your book really helped me do better. I found it very immediately motivating.

Oh, I'm glad to hear that. Yeah, I think a lot about how we've got all these great health messages, but some people do respond to certain things better than others or respond more strongly to certain cues than others.

So we're going to get into the book, into the science. But first, I'd like to learn a little bit about you and your background. How did you come to dermatology?

Well, when I was a student at the Baylor College of Medicine, I did a rotation in pediatric dermatology. And I was really just really drawn into helping children with eczema, which has only grown more common since that time. And so my specialty is actually helping people with chronic dermatitis of the skin. And so that's where I've spent the bulk of my career.

So I imagine that pediatric dermatology is seeing people with like disfigurements, with things that can not only could be dangerous and painful, but also like really reflect on their self-image, especially at that young age.

Yeah, that's correct. And I have to say pediatric dermatology is what inspired me, but my practice is adult dermatology now. And whether it's a child or an adult, you're absolutely right. I mean, something that's very visible. Let's say if it's on your skin or your hands, it can really affect people's self perception and also how others respond to them. So I think it yeah, it can be a real concern for many people.

Mm hmm. So when did you arrive at the heresy that lifestyle can affect our skin?

Because I never heard that, you know, I had, you know, rashes as a kid and like, no one no one in the medical world ever said that what I was doing or not doing, you know, except maybe there was a debate for like 10 years, like just chocolate cause acne. But that was it. Right. So how did how did you make food and lifestyle like a significant part of your practice, a defining part?

Well, it's really interesting you say that because there is sort of trends in medicine, right. Where and if you look at the history of diet and dermatology, they talk about how in the early nineteen hundreds people would talk about, let's say, for acne, how important it was to stay away from sugar, let's say. And then we had research that came out into the nineteen sixties that was not well designed and they were small studies, but they got this message out that no, there's not a connection.

And I remember I trained twenty five years ago and at that time we were still telling our acne patients, no, you don't have to worry about what you eat. And so it's only really in the last 10 to 15 years that the research has started coming out. And as you start to pay attention to the research. So I started to really pay attention to all of these research studies that were coming out. And it really drew me into the fact that, you know, our journals were publishing this in.

Amazing research, but it wasn't getting out into practice, and so that's when I really started not only seeing what research was out there, but really starting to put that together into educational materials and to review articles and trying to reach other physicians and also trying to reach my patients. And and I've been talking about food a long time just because of what I do. I specialize in allergic reactions of the skin. And so I got so many questions about food allergies and that was kind of the launching pad to me to say, you know what, I'm going to learn everything there is to know about this area so that I can really guide my patients.

Well, I guess there was there must have been some sort of cognitive dissonance around the message. Food doesn't affect your skin except if you have a food allergy, that it definitely affects your skin. Like it seems like one of the other one of the others isn't true.

Yes. That's such a good way of putting it. I've never thought of it quite that way. But you're right for, you know, for centuries in dermatology, we've been talking about, OK, if you have a vitamin deficiency, you are going to develop a rash, you know, whether that's like scurvy or pellagra, like we've known about that. Or if you have diabetes, we know we've known forever that that's going to affect your skin. Maybe you have poor wound healing or maybe you develop certain rashes that are unique to patients with diabetes.

So you're right. Cognitive dissonance. Yes, it affects it in this way. But we're we're now starting to sort of circle around that conversation and approach it more holistically. Like, yes, it affects your skin in many more ways than that. Hmm.

Can you talk a little bit about the study design? Like, was it like we know that the sugar industry has been notorious and recently discovered that they've been, you know, fiddling around with research for a long time to to implicate other things besides sugar. Were they involved in this 1960s research?

I do not think so. I had I had not heard of that. I think it was just a matter of not being designed well. And, you know, some of the foundational studies that affected what we told our patients for decades were based on these small studies, like 60 patients and with acne. And they gave half of them a chocolate bar and half of them a very similar bar that had no chocolate but did have sugar and trans fats. And so at the end of and I think the studies were only like four weeks long at the end of those four weeks, they said, well, these two groups of patients, you know, they have the same degree of acne.

And so it clearly is not the sugar, it's clearly not the chocolate. So diet does not affect acne. But I mean, as I'm sure you just picked up on on this, you know. Yes. That other bar didn't have any chocolate, but it still had sugar and it still had trans fats. So it is kind of a matter of looking at the wrong culprit. But, yeah, it just affected us for a long time.

Yeah. I mean, because even at that time, like, I knew people who would eat certain things and their skin would break out and we would say, well, you know, you must have read that somewhere. It was probably it's probably a placebo effect or psychosomatic. Wondering how how research when you're talking about a food like chocolate, like how do you fake people out of that, whether they're eating chocolate? Like, how did the studies get better designed?

Yeah, well, now so the study design that I thought was really interesting was they approached it from a different angle. So they took, again, randomized control trial. They took two groups of young men and one group had a low glycemic index diet. So they were told to replace all their processed carbs with Whole Foods. And the other group was just told to follow their regular diet. And then at the end of 12 weeks, and it can take a while to see results. Four weeks for acne is typically not enough.

So at the end of 12 weeks, they found a significant benefit for acne with the low glycemic index diet. So just designed these studies completely differently.

Mm hmm. OK, so they're not they're not looking at specific foods so much as patterns of eating.

Correct. Yeah. And that's one nice thing I'm saying, is that we're moving away from like a single food and really looking at your entire diet and the entire, you know, the quality of your entire diet, your pattern. Mm hmm.

Well, so I'd love to dive in, and I, I don't know if I'm embarrassed to say my first question is it's an honest question. It's not like me setting it up for my podcast listeners. Like what is skin?

Oh, that's a good question. That's a good question. I've never heard. Yeah. So if we think about skin, it's an organ and it's actually the largest organ in the body. And so anything that provides that outer protective covering protection for your body is considered your skin. And that is. Everywhere. So so its job is essentially protection is its primary job, its primary job is protection, but it definitely has other functions because, well, protection is key because it's protecting you against, you know, the environment.

It's protecting you against microbes. It's protecting you against irritants. It's protecting you against temperature change. It's protecting you against physical harm to the to the inner organs. But then it also has other functions. So it's involved in sensory processing, providing information about your environment. It's involved it has its own components of the immune system that are found located in the skin. And so there's a lot more to it than just protection. But that is its main primary function.

Now, it also - I know from experience - sweats.

Oh, yeah. Temperature as a runner, especially. Right. And then me, I'm in Houston, so, yes, temperature regulation. Huge said you're absolutely right.

And it also lets things in. Right. We put we put creams on because some things get through to sort of a smart filter.

Yeah. Yeah. Smart filter indeed. Yeah. There's certain things you want to be absorbed through your skin and other things that you want to keep out. So yes. And that's such an important part right now. I mean, if you think about there have been recent warnings about hand sanitizers that contained methanol, which if you rub it on your skin, can get right through that barrier. So that's a very important function. You're right.

So, you know, when I think about synthetic substances, artificial things that are created, I can't think of anything that works like skin does that that can do all of those different functions which seem either like, you know, completely unrelated to one another or even contradictory, like protection versus letting things in and out. What differentiates, like the structure of skin from other parts of the body, that allows it to do all these tricks?

You know, that's a really I love the way you just said that, because you're right, there's nothing synthetic that can do as fabulous a job as the human skin. And part of the way and I always say, like the human body is designed so beautifully, it's just hard to replicate that. So one of the ways it does that is it has several layers. And so we talk about the epidermis as being the outermost layer and the dermis, the layer below that and then the fat below that.

But within those three layers, there's so many different components. So there are definitely, you know, sweat glands. And within the top two layers, we have a lot of immune cells and a lot of sensory organs. But the main way that it protects us is just the way it's designed. It has a lot of people describe it as cement and mortar. So you've got blocks that really are building blocks of your skin that provide a lot of protection.

But then you've got little gaps between them that allow, you know, water in and out, let's say. And within those gaps, we have lipids that help fill in those gaps. So all of those different pieces together or what allow it to do these different functions.

And so there is there any way in which the skin can be analogous to a muscle in terms like I'm thinking about things like like in my experience, like calluses or like like so many.

Like when I think about lifestyle in general, I think human beings are living a very unnatural lifestyle. We're eating weird foods. We're not exercising. I'm also wondering, is there a component that we're we're we're we're soft, we're surrounded by soft things. We're not like bouncing against trees and sleeping on rocky ground.

Is there anything about the skin that needs to be used more than we're using it?

That's interesting. No, I haven't necessarily heard of it exactly that way. I think Callouses is definitely important. Your skin can respond to outside forces and it can change in response to those outside forces. But I think in terms of, you know, bumping up against things, your skin can adapt. We haven't lost that ability to adapt. But one thing I will say that we are starting to notice is that one of the things that we're seeing is this.

Our immune systems have become more jumpy over time, sort of hyper reactive. And we're starting to see that with our skin as well, that we are starting to see increased rates of certain skin conditions, perhaps in response to all of these changes in our environment. But these are talking about skin in. Laboratory conditions. So that's one area where I think, yeah, what you're talking about comes into play and some of it there's a gut skin connection that seems to be in play also where when you mess with the gut microbiome, that you might also be affecting the way your skin works.

Does that do you think that has anything to do with the microbes sending messages to each other? Because I know that our microbiome is also on our skin as well as in our guts. Yeah.

So it's a really interesting area of research. It hasn't been fully proven, but that's one theory is that, yeah, the gut microbiome might be communicating with other microbes in and on our body. But right now a lot of the focus has been on the gut microbiome, producing metabolites like short chain fatty acids, producing substances that we know help strengthen the lining of the gut, but have also been shown to help strengthen the skin barrier function to really help that skin barrier function even better.

So that's one way that we believe they're connected. Hmm.

I guess the gut is sort of a type of skin, right? We don't want a leaky gut. We say we want some protection and integrity, but we also want the right things going in and out.

Yeah, I think it's very similar in that sense that, yeah, it has to act. The lining of your gut has to protect you, but it also has to be a smart filter, just as you said. So there are a lot of similarities and that sense from a functional standpoint of how our skin barrier works, too. Mm hmm.

Right. So in the book, you talk about sort of two main things. You talk about like these, you know, conditions and diseases, the eczema and dermatitis and all that. But you also talk about just normal skin and you redefine like aging, right?

Yeah, like it's what we think of as I'm getting, say, you know, jowls in my skin is sagging and it loses its glow. And I'm getting wrinkles like most of us think of that as normal parts of aging. But you're saying that you can speed it up or slow it down. You can change the dial based on a lot of decisions that you make.

That's right. Yeah, absolutely. And I think a lot of people, when they think about aging skin, they think of two things. One is just age and the second is UV radiation, how much sun exposure you've had. But you're absolutely right. All of your lifestyle changes we're starting to find with more research can affect it. And I'll just give you one example of, you know, when you look at certain people, you can start to wonder, like, why do they look younger than somebody else?

And I'm presuming that they've had the same degree of sun exposure and that they haven't had any cosmetic procedures. But they actually did this great study in the Netherlands where they looked at elderly Dutch individuals and they controlled for all of these other factors what their weight was, what kind of sun exposure they'd had. And after controlling for all those other variables, what they found was that if you had a healthier diet, you appeared younger, visibly younger. On the flip side, if you had a eating pattern that was dominated with red meat and snacks, you had more wrinkles.

And so it's kind of interesting. We're starting to approach this question from lots of different angles. And I think the population research studies are really interesting, you know, and that's just one example. There was another and I think this example is so interesting where they looked at a group of individuals and they measured their blood glucose levels and none of these individuals had diabetes. So these were all non-diabetic patients. But as their blood glucose levels increased, what you started to see was that they developed more wrinkling based on independent assessments of their wrinkle status.

So we're starting to see more evidence like that.

What are the mechanisms? You talked about red meat and snacks and by snacks, I'm translating is like, hi sugar. Yeah, hi. Hi. Fat. White carbs.

Yeah. Processed carbs.

So what do we think or know are the connections between those classes of foods and aging skin?

Well, I'll give you so we know that there's three main factors that age the skin. There's oxidation, there's major and minor inflammation, and there's glycation. And I'll just talk about glycation first, because that's where the process snacks and the red meat really come into play. So glycation, you know, from a chemical standpoint, it's the process whereby a sugar molecule binds to a protein molecule. But the way I describe it for my. Patience's, you want to think about caramel, if you think about caramel, you're putting sugar with butter and you end up with this really sticky, gooey substance.

Well, that's what happens when you have high sugar levels in your bloodstream, in your body, those high sugar levels combined with the proteins in your body. And they produce a new substance, new compounds called advanced glycation end products. And we call those ages for short. And those ages are kind of like sticky caramel because they glob on to your collagen. And when you have all these sticky substances glomming on to your collagen, you you just end up with this kind of tangled mess.

If you think about collagen kind of being like a soccer net, you know, one of the reasons collagen works so well is because it's got all these evenly arrayed fibers, kind of like a net, and that's why it just bounces back. It's so, you know, it bounces and then it comes back to baseline. But if you stuck a bunch of caramel in there, now you've just got this tangled net. And so what happens is you start to lose elasticity, it starts to get stiff, and over time it just starts to sag.

So that's why, you know, eating these processed carbs that raise your blood sugar levels ultimately start to damage your collagen. And the way the red meat comes into play is you don't just produce ages in your body. You can actually eat them. And when you when they've done research studies on what foods contain ages, the highest levels were in bacon. So some of the highest levels were in things like fried, grilled, roasted and broiled meats.

So your bacon is not the fountain of youth.

I know, right? So it's not like if you want your skin to look like bacon, eat bacon.

Oh, yes. And it's so interesting because when I think of, like, eating sugar, I think, well, it goes into my stomach and like it knows what to do with it. Like, I know it's not good for me, but my my sort of mythical picture is sugar goes into my body and it gets handled more or less. But but you giving me this image of like a soccer net full of caramel like this, the skin.

Yeah, that's very different.

That gives me a very different relationship with sugar.

Yeah. Right. I mean, I think you're right for a long period of time, certainly our bodies know what to do with that sugar, but once it kind of overwhelms the system. And the thing about that caravel on your collagen, your body, it's it's permanent. So you can prevent future production of ages. But once the ages are there, it's permanent. You can't reverse that. Once the damage is done to your collagen, it's done.

So that's what makes it really so challenging. Hmm.

And I mean, you know, I don't know the exact figures, but sort of the beauty industry, the skin industry must be multiple billions of dollars a year.

Oh, it's it's huge and growing.

Every time there was one there was one study that I just referenced where the Global Beauty Supplement market, and this is only supplements, was expected to reach seven billion dollars in the next few years. People are really hoping that they can take a pill and sort of undo some of the damage that they've done over, you know, over the course of many years.

So, I mean, one of the words popped into my head when you're talking about collagen is I know people are trying to eat collagen or drink collagen and bone broth and any evidence that consuming collagen makes your skin better.

You know, it's so interesting that you ask that because they have put out several studies and there was a recent journal article where they looked at 11 different randomized control trial and almost all of them were either funded by the manufacturer or supported by the manufacturer. And then they reported on these outcomes that are pretty not that impressive. You know, I think people think that they might drink collagen supplements and their wrinkles will go away. But they looked at things like water loss from the skin or, you know, very vague outcomes.

So I personally have not been impressed by the research that's out there. I do not take supplements like that myself. What they're describing is pretty minimal. You know, the results that they've been describing are not that impressive be the studies have been all over the place, all sorts of doses and types. See, a lot of them have been funded by the manufacturer and the. There's so much we don't know about what they're putting in there, we just did a study where we pulled a bunch of supplements off the off the shelf to look at where they're getting their collagen from.

And half of them didn't even tell you. Is that from cowhide? Is it from cow hoofs? Is it from fish skin? So personally, I don't take collagen supplements.

Mm hmm. And so before we get to food, are there any supplements that do work?

In general, I am a strong proponent of foods over supplements. I will say that if you are, of course, deficient in a nutrient, that supplementation is very important. So but if you're talking just purely baseline, your nutrient status is normal. Is there any supplement you can take to sort of supercharge skin benefits? We haven't I haven't found any impressive evidence and there's been a lot of research about things like biotin and saying above normal levels. I haven't been convinced by any of that.

I do have to say some interesting research on probiotics and prebiotics being done. I'm keeping an eye on that. Also, some interesting research about nicotinamide, which is a B vitamin. I'm keeping an eye on that. But but nothing definitive yet.

Gotcha. All right. So now let's talk about food.

Is there's evidence that the certainly the you know, the whole food dietary pattern, heavy on vegetables, heavy on plants is preventive. How good is the evidence? Well, you mentioned the Dutch study sort of in general, but we're looking at like a population. I'm sure there's not that many people in elderly people in Holland that like the really pristine end of the scale.

How good is the evidence that, like whole food diet heavy on plants is protective?

I have to say we definitely need more research on the full dietary patterns. That's what we're lacking right now. I can tell you that we have lots of evidence if you're looking at sort of individual nutrients or individual foods. We have lots and lots of animal studies and bio biochemical studies, a decent number of human studies. What we're lacking is those big population studies. But there's enough pieces that we're putting together that I feel very strongly that we're seeing benefits.

And that's because if you look at the components of it, where you're eating powerful nutrients, we know that those have antioxidant and anti-inflammatory properties and that's beneficial. And then we also know that you're talking about diabetes prevention with a Whole Foods plant-based diet. And when you're talking about diabetes prevention, that's huge in terms of the skin. Diabetes is incredibly harsh on our collagen.

So I think standpoint well, diabetes, we've known this for centuries, that people with diabetes have poor wound healing. And as we start to look into that, one of the reasons that that is the case is because those high blood sugar levels from diabetes, they start to damage our collagen. And so that damage of collagen, OK, on your skin, you start to see it as sugar side, which is what I call it, where you start to get more wrinkling and more sagging of your skin.

But, you know, those effects on collagen are what we see in the blood vessel walls, and that starts to impact your risk of hypertension and cardiovascular disease. So it's all interconnected. Mhm.

Yeah. And what you just reminded me of something that I took note of in the book, because you talk in the very beginning about like The Miracle of the Skin, like that terrible paper cut you got on your thumb is that you can't even type two days is completely healed as if it wasn't even there. Yeah, the skin is like the part of our body that we get to to witness as a miracle.

Right. Because you can't see the insides doing that, right? That's right.

Yeah. I think it's so amazing that you can just. Yeah, exactly. You see this horrible cut on your skin and then just two days later it's gone. And that's because your skin just has these beautiful systems to regenerate. So you can actually see your skin regenerating in front of you. And that's why the right foods are really just acting to supercharge those powers. Mm.

Yeah. And another thing that just came to this, when you're mentioning sort of, you know, the challenges of doing population research. So I think, you know, with like heart disease or diabetes, there's this sort of like it makes sense to me that on the inside we're all the same. But clearly on the outside, different people have different skin, like different groups of people. Are there differences in like there's just one skin?

Age better than another or less or more sensitive to certain things, like we know that you have a darker skin. I believe more resistant to sun damage.

What is you know, or is there opportunity to learn more interesting things because of these different skin types or does it interfere with research?

I think it would be a fascinating area to study, but there's been hardly any research done in that area beyond sensitivity to UV radiation. So right now, that's what we focused on, ethnic and racial differences, how they respond to UV radiation. But that is definitely a fascinating area right now. We don't have any evidence that if you're of a different ethnic group, that your collagen let's say would react differently to foods. So we haven't seen that.

So right now, I approach everybody very similarly.

Gotcha. So you said we do we do have, I guess, reductionist evidence about specific foods and skin health. Oh, yeah.

So while we're waiting for the patterns. Yes. What are the what are the puzzle pieces that we have? What are the what's the most the strongest connections of, like, happy skin foods?

Well, I'll tell you that I think one of the easiest ones to measure in terms of human volunteers is how well they can protect themselves from sun exposure. So one of the questions that researchers have asked and I've asked is, OK, can you make your skin sun stronger? In other words, can you make your skin more resistant to a sunburn, let's say? And we've actually been able to demonstrate that with multiple foods. And there was one study that I just loved because this is kind of how you would design a pharmaceutical study, like you would give a person a pill and have them take it every day for 10 weeks.

But what they did was that they gave these subjects two tablespoons of tomato paste. So they ate tomato paste every single day, two tablespoons for 10 weeks. And they measured how quickly they would sunburn before and after the 10 weeks and after the 10 weeks of keeping everything the same. Just that tomato paste, they were actually able to be sun stronger. So they did not sunburn at the same level. It was really remarkable, if you think about it, because, you know, if you were to ask somebody how quickly do sunburn, you don't think of that as something that you can change.

But this study showed that you can and they've repeated it multiple times with tomato paste, with tomato paste and olive oil. They've looked at pomegranate. So they've looked at sort of different foods that can that can cause this effect, green tea, polyphenols. So it's interesting to me that I mean, it's fascinating that you can you can change your sensitivity to sunlight.

Mm. Yeah. I mean, that goes into this whole sense of like, why would the sun be bad for us, you know.

Yeah. Because I grew up essentially scared of the sun. But you know, if we have the heart like I actually came from a family where I used to put tin foil on your nose at the beach. I understand we're supposed to avoid, like, really, you know, devastating burns. But like, I grew up scared of this. Like, the sun is the bad thing in the sky to protect yourself from it. It doesn't really make sense from an evolutionary perspective.

Like my ancestors were living in caves and under rocks and, you know, and we only make vitamin D from sun exposure. So it seems like, you know, if we look at the Paleolithic human diets, you know, 100 grams of fiber and all these plant foods that maybe the food itself was like super sun protective.

Yeah, I suspect that there is a lot to that. And also, you know, the whole sun exposure thing, there's certainly a spectrum of it where, you know, you don't want to live in a cave the rest of your life, but you also absolutely don't want to be getting those blistering sunburns. I think what you said is really interesting, though, that that they were eating such highly nutrient rich foods that they were consuming protection from a lot of these environmental factors.

And it's not just, well, you know, in modern times we've got stress and pollution in addition to UV radiation that's really amping up our free radical, you know, free radical production. But yeah, in in Paleolithic man, I can just imagine that they had worked out all these systems to protect themselves from all of these intense situations.

You said stress can can damage our skin. Yes.

So, you know, one thing you mentioned was how does sun actually damage our skin? And I talk about the fact that UV radiation increases the production of free radicals and the skin. And I think of free radicals as these really damaging compounds that are just unstable and they're ping ponging around in your layers of your skin, but in the process what they're doing is they're damaging the proteins of your skin, like collagen and elastic fibers. They're damaging the DNA in your skin.

They're damaging the lipids in your skin. And so when you think about everything that free radicals are doing, so UV radiation is not the only reason you develop free radicals. Stress can also increase the production of free radicals and even just the processes of normal living. You produce free radicals during that process. Hmm.

You mentioned earlier that one of the processes of aging is inflammation. So inflammation is what happens when I cut myself, right?

Yeah, that's right. But you can have major inflammation like you have a cut, but you can also have micro inflammation. So if you talk about this process of free radicals ping ponging around in your skin, they cause damage. But inflammation is really just your body's repair processes and chronic inflammation is those processes that are just out of control. So if you think about free radicals in your skin, sometimes those free radicals cause damage. And so your body jumps to repair that damage.

But sometimes that repair process goes out of control and it causes more damage than what you started with. And that's that process of chronic inflammation and that process of chronic inflammation also causes damage to your skin.

To this is this is like the Roomba chewing up my carpet after it cleans up.

Yes. I like that a lot. Yeah, exactly. Gotcha.

So we know what we know about tomato paste pomegranates. You talk a lot about spices.

Yes, I talk about spices and herbs as being triple threats because I talk about the three main processes that damage your skin oxidation, inflammation and glycation. Well, spices and herbs actually can combat all three of those processes. So they have high levels of antioxidants so they can quench those free radicals. They have high anti-inflammatory powers and they're even anti glycation. So they can even interfere with those caramel compounds glomming on to your collagen. They can even interfere with that process.

So that's why I talk about them as being triple threats and so important for healthy skin.

So what are some examples?

Well, I think the one that a lot of people have heard about is cinnamon. So I think Cinnamon is one of these great spices that we probably that maybe some of us use, but could use even more. But it goes way beyond that. They've actually shown really impressive results from in the laboratory and animal studies from things like cloves. I'm going to put garlic and ginger in here, even though they're not technically necessarily spices and herbs. But we've also seen beneficial effects from oregano, from time, from saffron, from cilantro.

And if I haven't named a spice or herb, I kind of suspect that it's probably just because we haven't chosen to study them. And I'm going to name the big granddaddy of them all, which is turmeric. That's what a lot of people have heard of. But that's been studied much more extensively and lots of powerful benefits there.

So how do they work? I mean, what I mean, spices are sort of like the bark or the berries. They tend to be like spicy rice. They tend to have very concentrated, intense flavors. Is there something that's right. Is there something about like this? You know, the signature I don't know if we're getting this sort of homoeopathy, but something that tells human beings like this is a powerhouse that's connected to the fact that it's like highly tasty.

I think that's interesting. But what we focus, what the research is focused on is really specific compounds like they've tried to really break this down. And the research that we have to date has shown that specific compounds in those spices and herbs. So, for example, in turmeric, curcumin is just one component. And they've studied that in the laboratory and that's where they've shown that it has all these beneficial effects.

So I think, you know, we've broken it down into these different compounds and whether it's from the bark or the berry or the or the leaf or the twig, I think it's just the fact that they're so concentrated, these natural antioxidant and anti-inflammatory compounds that spices are just highly concentrated sources of those.

So most of the patients you see are coming in with conditions and diseases as opposed to healthy people who want to prevent aging. Right.

Yeah, that's. Correct, yes. So I write a lot about how to use food to combat aging of the skin, but in my practice it's focused on patients with chronic skin inflammation.

So the thing I have heard that we give to everyone with chronic skin problems are steroids, which are essentially stress chemicals. So which is interesting. Yeah.

Do can you work with people or are you just prescribing the standard medical pharmacopeia or can you work with people with just skin disorders through lifestyle as well?

Well, my practice specifically is focused on patients with allergic skin reactions. And so a lot of what I do is really focused on lifestyle in the sense of let's change your skin, care to eliminate anything that might be bothering your skin. And then let's also give you information, if it's relevant about food allergies and then if there's any way to maximize your skin's healing potential, you know, by using powerful foods that help your skin heal. And also considering the role of the gut microbiome eating to help the gut microbiome, to also help your skin barrier.

So I approach it from that standpoint, but my practice is really concentrated on patients with allergic skin reactions. So I do prescribe steroids when needed. I mean, I talk about the fact that sometimes if your skin is out of control, you need to just quiet that fire quickly. And so I use steroids in that respect. But in my practice, steroids are really meant to be used to calm something down quickly and then to be withdrawn while we're finding other ways to help your skin improve.

So definitely one tool in my armamentarium.

So given that steroids can work quickly, do you find that your patients have stress responses that lead to allergic reactions, even independently of food?

You know, the way I am, this is another area that's really interesting. Intense stress can definitely cause behaviors such as scratching that could worsen the skin. But even independent of behavior change, stress can stress does seem to increase skin inflammation. It is rarely acting alone, though. So I always tell my patients stress did not cause your skin inflammation, but stress might be contributing to it. So one factor.

So it might push it from a nine to a 10 and it becomes a manifest sometime.

Yeah, that's a good way of putting it.

So when you do work with with people, is it there's a lot of elimination now. I don't know anybody who's allergic to sugar per se.

So like sugar is like the circus. It's the big problem, but it's not implicated directly in what you're helping people with. Right. How do you navigate that?

That's correct. So it's not implicated directly. So in my patients with skin inflammation, we're not necessarily talking directly about sugar. We're talking about other things that they might eliminate. Although I have to say one way that it might play a role with skin inflammation is if you have a high sugar diet. We know that that damages good gut microbes. And one of the secondary effects of that might be more skin inflammation. But, yeah, typically the sugar conversation is for patients with aging skin more than more than skin inflammation.

Mm hmm.

So, I mean, do you work with people for whom a dietary change is a challenging thing to talk about?

I know, because I'm focused on sometimes there might be food allergies playing a role and in the skin. That's an easier conversation, I think, to have. I can say, well, your test showed this, so let's eliminate that. It's definitely a harder conversation to talk about changing your entire eating pattern. But in my practice, since we're just focused on skin inflammation, I'm typically not discussing the entire eating pattern. But what I do is I do refer my patients to additional sources to to really focus on, OK, well, how can you eat the most anti-inflammatory diet possible, which may have a benefit on skin inflammation as well?

Mm hmm. So where are you hoping that research goes like, well, what are you, like, really curious about the hope will be explored and discovered?

What I really want are randomized control trials of skin disease treated with an anti-inflammatory Wholefoods diet. I mean, that's where I really want to see it coming. And I know there are people applying for grant funding right now in this area. It's a challenging area to to achieve grant fund. For that, that's really my hope, whether it's a patient with psoriasis or eczema or rosacea, I really would love to see randomized control trials of that anti-inflammatory diet.

How is it going to help your skin? Hmm.

Well, why is it so hard to get funding for that?

Well, I think there just aren't as many funding sources for that approach as there are. As I'm sure you, you know, is there are four pharmaceutical approaches. And with the NIH, there's, you know, so pretty much you're going to the NIH and they have so many competing grant applications. But that's the dream. That's what I'm hoping for.

And what was your what was your goal in writing Glow, since, you know, your practice doesn't appeal to the people who are going to read this necessarily, except, you know, the psoriasis rose to see eczema. Folks like you wrote a book for for people like me who want to have healthy skin as they age, what are you hoping to accomplish? Or are you thinking about expanding your practice or doing other things or just the book is out there?

No, I really I mean, I had several goals with the book. One was to get more dermatologists talking to their patients about it. I'd really love to see my field talking more about this intersection of diet and dermatology. I've also written a lot of medical journal articles which can be harder for patients to access and understand. So I really wanted to put it in layperson's terms in a really accessible way. And then finally, I have to say that, you know, in my own health journey, I've come to the conclusion that vegetables are the key.

You know, that there are just so many health issues that would be improved if we ate a lot of vegetables, a lot more vegetables in addition to to all the other healthy foods. And so I wanted to give my patients and my readers and members of the public just one more reason to adopt a healthy Whole Foods diet. So that was my you know, and of those really my my overriding goal is to just add to that conversation, give people another reason and show them that it really is impacting not only these other health conditions, but even just from the day to day.

You know, how you look in the mirror. If that's one more motivation, if that's the motivation you need. I want to make sure that you have the research that shows that it does make a difference. Gotcha.

So I found out about you from a plantation project email that you're speaking at the Virtual Plant-based Nutrition Health Care Conference. Are you getting opportunities to speak to your peers who are not necessarily lifestyle medicine aficionados and others?

I do, yes. I'm so excited about speaking at the plantation project. So I've spoken on the national level to a number of dermatology organizations. So I've really focused on spreading my message there. And then certainly in the universe, the the medical schools in this area and the hospitals that I'm affiliated with, I'm working on spreading that message there as well. But I would love to reach a wider audience as well.

That's not health care professionals from the health care professionals. Do you get pushback or skepticism?

You know, it's interesting because I first started writing about this over five years ago, and I think at that time there was a little bit of skepticism. But now and it took me three years to I had to apply to give a talk at my national conference three years before I was finally accepted to give a talk. And since then, I think the pace of acceptance has really accelerated among the dermatology community that they're starting to see with all of this different research that's coming out there.

We're starting to really see adoption of this mindset that, of course, what you eat is going to impact your skin. So I'm so hopeful. I'm just seeing a lot of changes in how we're thinking about this area also.

So congratulations on your persistence. Thank you.

So you you've gotten under their skin.

I love that. Yes, I got that fun.

All right. Well, the book is Glow, by Rajani Katta, MD. And you have a website as well, right. For people can find out more.

I do, yes. So I've really focused on putting a lot of my handouts just up on my website. So anybody who has rosacea or eczema or psoriasis, if they want to see what the evidence shows about foods for those conditions, they can just go to my website. And it's And Katta is my last name. I've got a lot of handouts there.

One final question, yeah, and you can punt if you want.

I like I like to ask people like what music are you listening to that other people might not know about that you enjoy and want to share?

Oh, goodness, I'm not specific. I like I do love, though, just salsa music in general. I don't have a particular OK, I don't have a particular band or anything that I follow, but I just love to put that kind of channel on. Just listen to salsa music.

That's well, you know, tomato paste works. Why not salsa music? There he goes right with the theme, huh?

Yeah. All right. Well, I'll go I'll see if I can grab a good playlist to take people out with. So, Dr. Rajani Katta, thank you so much. Thanks for this wonderful book and thanks for the work you do. And thanks for taking the time to talk with us today.

Oh, thank you for giving me this opportunity. I really enjoyed it.

Enjoy, add your voice to the conversation via the comment box below, and please share – that's how we spread our message and spread our roots.


Dr Katta's website:

Glow: The Dermatologist's Guide to a Whole Foods Younger Skin Diet

Salsa Playlist

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