Macular Degeneration

April 8, 2018

Did you know that what you eat affects your vision? Listen in as we talk with Dr. Chris Knobbe about all aspects of age-related Macular Degeneration, including what happens to your vision, and the risks and causes for developing AMD. You will come away with some nutrition tips to both prevent and treat Macular Degeneration.

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Transcript

DAR:  Welcome to Dishing Up Nutrition, brought to you by Nutritional Weight & Wellness. I'm Darlene Kvist certified nutrition specialist and founder of Nutritional Weight and Wellness. You know, I started Nutritional Weight & Wellness almost 30 years ago with the intention, and I was already old by that time, with intention of teaching people how food affects their health. Then about 13 years ago, we started spreading the eat real food message worldwide with our live Dishing Up Nutrition radio show, which then quickly turned into a podcast featured on iTunes. We didn't know what we were doing. Just happened. You know, we've had numerous topics, but today's show on macular degeneration may just be one of the most important topics we've had the honor to bring to you. We're going to discuss how food, think about this, how food affects macular degeneration. With ophthalmologist and author, Dr. Chris Knobbe.  Joining me today on the other mic, right over there, to help ask our guest all the key questions and to take your phone calls because I think many people are gonna want to call in today and this is Lea Wetzell. She's a certified nutrition specialist and we're going to have a great show Lea.

LEA:  We are. Good morning Dar. Last fall, Dar and I both attended an amazing presentation on eye health at the Wise Tradition Conference held in Minneapolis, Minnesota. We both agreed that we needed to spread that message of what you eat affects your vision, which maybe a new thought for some of you.

DAR:  I know a lot of people, I bet they're saying really? What I eat affects my vision? So this morning we are so pleased to have Dr. Chris Knobbe joining our discussion today by phone. Dr. Knobbe is an ophthalmologist and author of Ancestral Dietary Strategy to Prevent and Treat Macular Degeneration. Now that is a mouthful. Dr. Knobbe has also been a clinical associate professor at the University of Texas Southwestern Medical Center and currently is the founder and president of Cure AMD Foundation.  A lot of things he's doing.

LEA:  Welcome Dr. Knobbe. Thanks for being on today. You've written a remarkable book full of hope. We know that macular degeneration is at an epidemic level today and it is a leading cause of blindness. If it's OK with you, we want to ask you many questions, but please keep in mind that many of our listeners have been listening to us talk about the evils of refined oils and trans fats and sugars for several years. While some of our listeners are just tuning in today for the first time.

DAR: Dr. Knobbe, it's great, it's delightful to have you on the show and we want to help you spread your important message worldwide. So let's dig right into all the questions that we have this morning. So first of all, can we just call you Chris?

CHRIS: Absolutely.

DAR: Thank you. So tell listeners, what is macular degeneration?

CHRIS: First of all, it is an honor and a pleasure to be on your brilliant show. I love your show. Thank you so much for this opportunity. Anything at all that gets the word out about food choices and age-related macular degeneration is great work, so I thank you both and your entire team for helping to further spread what I believe is a vision-saving message.

DAR:  We totally agree with you and that's why we were excited when I heard you at the conference, I turned and I saw Lea and I thought we have to have Dr. Chris on.

CHRIS: Thank you.  To your question, age-related macular degeneration, which we'd normally call AMD, is the leading cause of irreversible vision loss and blindness in people over the age of 65 worldwide. So the macula itself is back at the central retina, at the back of the eye, it is where the light is focused. And it accounts for about the central 10 degrees of vision. The macula is only about 6 millimeters across, about a quarter of an inch. I would argue that's the most important quarter inch of tissue in our whole body. So if the macula undergoes degeneration we lose central vision. It's just a matter of how severe that is, which would determine how much vision loss we have. So if the AMD is really severe we might end up with a large central blind area in our visions.

DAR:  So that is kind of amazing. It is only, like you said, a quarter of an inch, right?

CHRIS:  Right, yeah. A quarter of an inch.

LEA:  So what are the risk factors of developing AMD or age-related macular degeneration for people living in the US?

CHRIS:  Since 1992, the risk of developing AMD in the US and many other developed nations, has been nearly one in three. So it's incredible. But almost one in three Americans can expect to develop some degree of AMD in their lifetimes.  Worldwide, one of every 11 people over the age of 50, which is 8.69 percent of those over the age of 50, already have or they will develop AMD. So the risk overall of developing this disease is staggering.

DAR: It has to be. It's amazing because if you think, you know, I always put this in perspective, I think OK, about 10 percent of the people are chemically dependent, they say. I think it's higher than that, but they've always said that in the past. So we almost have as many people with macular degeneration as people with chemical dependency. That's kind of amazing, isn't it? I mean, you know, we never think in terms of that. So what then was the risk of people developing macular degeneration say a hundred years ago or so?

CHRIS:  I'm glad you asked.  The short answer is that in the late nineteenth and early twentieth centuries from around 1850 to 1920, there is ample evidence to conclude that macular degeneration was an extremely rare disorder. And then AMD began to increase in frequency in the 1930s, at least in the United States and the United Kingdom. And by the 1970s we were at epidemic proportions of disease in both of those nations with most other developed nations following suit like Japan, China, India, and so on. So let me just back up. I want to say that if I could, in 2013 when I first understood ancestral nutrition principles, that's when I came across Weston A. Price's book Nutrition and Physical Degeneration. And after understanding that, I developed this hypothesis in my mind at that point for the nutritional basis of macular degeneration. So now I've been in ophthalmology since 1991, and let me just say we ophthalmologists have collectively believed for many decades that macular degeneration is a result primarily of aging and genetics. So when I began to consider back in 2013 that macular degeneration might be caused by a faulty westernized diet, that it might follow man-made processed food consumption, just like heart disease, cancer, hypertension, type two diabetes, obesity, all that; I knew that if my hypothesis held water, if it were valid, not necessarily true but valid, the first thing we'd need to be able to show is that macular degeneration has been increasing in prevalence. If the disease was once rare or was rare in certain populations, and now we have epidemics of disease, then we have to ask ourselves what induced the increased prevalence of disease, right? And so back in 2013, I had no idea what the prevalence of AMD was historically so I began to investigate that and I was literally shocked to find, first of all, this had never been researched. In fact, it took me months to give you this, the answer that I'm giving you today, because only one other ophthalmologist had ever thoroughly researched the history of macular degeneration and actually published the findings. And this was an obscure paper that I came across after I'd already done my investigation. But without getting into all that nitty gritty detail, let me just say that what I found was that ophthalmologists could first see the macula back in 1851 after Herman von Helmholtz designed the ophthalmoscope.

DAR: Since 1851?

CHRIS: 1851, right. Just a quick nugget here is that it was 23 years after he published this design and ophthalmologist all around the world were using ophthalmoscope before even the first cases of macular degeneration where described. So, as I said, it was an extraordinary medical rarity up until the 1930s and then has had rising prevalence since that time.

DAR:  Dr. Chris, I think, well, I actually have a friend, a good friend of friend since fifth grade, who has macular degeneration and of course I think she believes that it is a genetic condition. So Lea, we do have to take a break, right? So Dr. Chris, I want to reemphasize that it is not a genetic condition. It's more a food problem when we come back from break.

LEA: That sounds great. You are listening to Dishing Up Nutrition brought to you today by Nutritional Weight & Wellness. Today we are talking about how food affects our vision with special guest Dr. Chris Knobbe an ophthalmologist and an author of the book Ancestral Diet Strategies to Prevent and Treat Macular Degeneration.

DAR: Welcome back to Dishing Up Nutrition. Dr. Chris Knobbe's book Ancestral Diet Strategies to Prevent and Treat Macular Degeneration digs deep into the science of macular degeneration so that we as listeners can fully understand why we have an epidemic of macular degeneration today. You know, this condition virtually did not exist a hundred years ago, so we have to ask what has changed, what were we eating a hundred years ago, and well, what are we eating today? Those are great questions.

CHRIS:  Right, right. If we go back just a little further than a hundred years, if we go back to 1880, then everyone on the planet was consuming ancestral diets. This was the case because at that time there was no refined white flour, there was no vegetable oils, no artificially created trans fats. We had sugar but in very small quantity. So we got refined white flour beginning in 1880, first vegetable oil production, cottonseed oil, that also came in 1880. Procter and Gamble started producing Crisco, our first artificially created trans fat in 1911. And all of these foods and then sugar all began to increase in consumption over time. And essentially what happened was that these foods began to replace and supplant all of our nutrient-dense foods, as you all know. So by 2009, 63 percent of the American diet, this good old standard American diet with the appropriate acronym, SAD, right? Those four foods are the recipe for metabolic disaster and now you guys have known this for a long time, I just learned this in 201. So this is the recipe for metabolic disaster, all of these foods, and this is what of course leads to heart disease, cancer, type two diabetes, metabolic syndrome, hypertension, obesity, and of course I believe macular degeneration. And our research supports this conclusion because we've looked at the data regarding processed food consumption and the development of macular degeneration in 25 nations. And in short, what we can conclude is that when people consume these processed-food laden diets for 30 years or more, particularly those that contain the polyunsaturated vegetable oils, most of us call the PUFAs, then we see macular degeneration hitting in epidemic proportions. So we see elevations to double digits of prevalence in terms of the rate of macular degeneration.

DAR: So Dr. Chris, let's go back over this a little bit. So when you say PUFAs a lot of our listeners of course understand that, but a lot of our listeners have no idea what you're talking about. So would you just list some of those fats that are in that category that people are consuming now, but they weren't over a hundred years ago?

CHRIS:  Absolutely. So the PUFA stands for polyunsaturated fatty acids and the ones that that are on that list really are soybean, corn, canola, cottonseed, rapeseed, grapeseed, sunflower, safflower and rice bran. That's all the ugly ones. So the healthy oils are the tropical oils, coconut, palm and palm kernel. And then we've got olive oil and I think if you get a real, true actual olive oil that's not adulterated with these PUFAs, then you're safe with those, but the PUFA oils are around 97 or 98 percent of the oils consumed in the US and they're just a disaster to our health and particularly for macular degeneration.

DAR: Can you describe to people what happens to the macula when people use those oils. I mean, I know this, I'm just throwing this question out because that's what I would want to know.

CHRIS:  You mean what happens to the eye itself or to the vision?

DAR: The eye itself. That's what people are looking for. What happens when they use these bad fats?

CHRIS:  Well, it's a really long answer and it's hard to summarize, but let me just say, first of all, in terms of vision, the first thing that's going to happen is people are going to have to start to have subtle visual loss. They might just  think they're getting older and they might begin to experience some definite blurring of visions, a little blind areas in their central vision, but they're never going to come in and say, I've got blind areas of vision. They're just going to say I can't see as well. I can't see to drive at night or I can't read very well. Things like that. And that's what would be consistent with the dry form of macular degeneration. But if macular degeneration goes wet, they can get distorted vision, which we call metamorphopsia, so things that should be straight turn wavy. And then so what's happening at the microscopic level is really that, now I can't prove this, but it's a sub-hypothesis, is that number one, I think that the vegetable oils are contributing to a vascular disease at the back of the eye. The eye needs a vascular supply more than any other organ because it's so phenomenally metabolically active.  And so what we see is that the choriocapillaris that feeds the retina with nutrition and oxygen undergoes occlusion. And so we see loss of choriocapillaris, we see thickening of Bruch's membrane, which is the layer that sits between the choriocapillaris and the retina proper. And I believe that Bruch's membrane will thicken in response to these oils and perhaps trans fat, and it produces a barrier to get oxygen and nutrients to the photoreceptors, the rods and cones and to the retinal pigment epithelium that support those rods and cones. So ultimately what happens is that the retinal pigment epithelium, what we call the RPE, it begins to undergo degeneration. And those cells begin to die and each one of those RPE cells supports 30 photo receptor, 30 rods and cones. So when the RPE cells die, the photoreceptors die. And the bad news is that neither of those are regenerative. We only get one set. And so if they're gone, they're gone forever. We can't bring them back. So this is why it's so important to correct the diet early and prevent vision loss. It's like a lot of things, you know, it's like having a stroke or heart attack. An ounce of prevention is worth a pound of cure. Right?

DAR: Exactly.

CHRIS:  Yeah. That's what's going on in it. And that's the dumbed down, dirty version.

LEA:  Which is still very complex.

DAR:  I know that Dr. Chris, we have a lot of callers on the line, so Lea should we take a caller?

LEA:  Yes, let's trying to fit one in before our next break. Awesome. Susie, thanks for calling Dishing Up Nutrition. You have a question for Dr. Knobbe today?

CALLER: Hello. So I do have a question, I'm 45 and I've been diagnosed with macular degeneration. I have the wet version where my field of vision gets wavy in the middle and I require injections about once or twice a year to clear up that issue. I'm wondering about diet and how that possibly could reverse some of these issues I'm having.

DAR: That's a great question.

LEA:  Great. That's what we wanted to get to next. So you talked, Dr. Knobbe, about this ancestral diet. Can you kinda describe what that entails that would be helpful for her?

CHRIS:  Yes. Well Susie, thanks for the question ,first of all, and it's a great question and let me just say first of all that ancestral dietary strategy really is, it's great at any point, but once you've gotten so far as to have wet macular degeneration, you absolutely must follow your ophthalmologist's advice and have the anti-VEGF injections that basically prevents these vessels from growing up under the retina and leaking and bleeding and causing havoc. But as far as an ancestral diet at Susie's stage, I think it's always appropriate, but you can't rely on that at this point essentially for your only treatment. But I do believe that is by far the best thing that she could possibly do, I mean along with her ophthalmologist's treatment. So you basically do both together. It's never too late to get started and at her age it would be really important to get on a diet that's going to help prevent progression of her disease.

LEA: Correct.  Unfortunately we have to take a break but we definitely want to hear the nitty gritty specifics of your answer to the question. So if you guys can just hold for one second on break. You are listening to Dishing Up Nutrition. If you are concerned about your vision, Dr. Chris Knobbe recommends five food groups to avoid. Number one, white flour, number two, sugar and high-fructose corn syrup, number three, the polyunsaturated vegetable oils. So examples of that would be soybean corn, cottonseed, canola, or also called rapeseed, grapeseed oil, sunflower and anything labeled vegetable oil. Number four is trans-fat, that is shortening or margarines, and number five is processed foods. This is also our recommendation from all of us at Nutritional Weight & Wellness and it has been the same message for the past 20 years. We'll be right back.

DAR:  Welcome back to Dishing Up Nutrition. Dr. Knobbe's daughter said "it's just too hard for most people to figure out how to eat healthy" and we agree it is difficult to figure out how to eat with all those mixed messages out there about what's good for you and what's not good. At Nutritional Weight & Wellness it is our mission to help you learn to eat healthy and it is our mission to provide the motivation for you to eat healthy. You know, we provide individual nutrition therapy sessions which are sometimes covered by insurance and we teach our Weight and Wellness Series either weekly or in weekend seminar type style where you get all six classes in one weekend or we break it down into 12 weekly sessions called Nutrition 4 Weight Loss. So you have to ask yourself, how do you personally like to learn? Do you prefer to learn over a weekend or in 12 weekly focused interactive sessions. You know, we have a number of options for you, so now it's up to you call 651-699-3438 to sign up or to ask all the questions that you want to or you can go to our website at weightandwellness.com to read about us and get more information.

LEA:  Great. So before break we were getting into the nitty gritty about the ancestral diet and how it can be beneficial for macular degeneration. Dr. Knobbe, do you want to get into some more specifics in relation to the diet that you've found beneficial?

CHRIS:  Sure, absolutely. First of all, let me just say that an ancestral diet is any diet that existed anywhere on the planet prior to 1880. Because back then there was no processed nutrient-deficient foods anywhere on the planet with the exception of sugar in small quantities. I think I mentioned this, but what we're seeing really is that as we have begun to consume westernized processed foods, particularly what we saw in the US and the UK, is that after consuming these foods for about 30 years or more, we began to develop epidemics of macular degeneration. And I think that is driven by  westernized foods in general. But I think of all of those, I think that the one that is most important is the vegetable oil. I might mention what we found in the South Pacific islands, Samoa, Solomon Islands and Kiritimati, three island nations in the South Pacific. These people are living on basically ancestral diets, not exactly anymore today, but over the last five decades, since the 1960s, they've been consuming mostly ancestral diets because they're such poor nations that these big food manufacturers don't even want to sell products to them. So they actually get no vegetable oils. And what we've found from all of their ophthalmologists down there who helped us in this research is that their prevalence of macular degeneration is about 0.2 percent. So we have here in the US 74 fold more AMD on average than they do. And really the huge difference is vegetable oils. They don't get them, we get a boat load of them.

DAR: So we would say in a very practical way, if you walk into your kitchen and you have vegetable oil there or soybean oil or corn oil or canola oil, throw it out.

CHRIS:  Absolutely throw it out. That stuff should be labeled with a skull and crossbones. Every single one of them.

LEA: So what fats are they consuming then?

CHRIS:  In the South Pacific you mean?

LEA: Yes.

CHRIS:  Yeah. What they're consuming mostly is they're living off the land, which, you know, they're very, very poor nations. But that's actually a good thing in terms of health, you know, so they're living off of fish and other seafood that comes right out of the sea, some root vegetables. And then  they get some fruit and the only oil they're using comes from almost exclusively coconut oil, which as you know, is, is a great thing.

LEA: It is great. 

CHRIS:  I mean, today you still see our Harvard nutritionists poo-pooing coconut oil because it's saturated, but you know, they don't get it. So far they're not going to, it doesn't look like. These oils turn out to be fantastically healthy. And wherever people were consuming saturated fats, animal fats and saturated a tropical oil, which is again, coconut, palm and palm kernel, I think we see those people in really good shape.

DAR: So the other saturated fats that come from animals you would recommend would be like butter, right?

CHRIS:  Yeah, absolutely.  Eat all the animal fat that you want. Saturated animal fat is extremely healthy. And along those lines, so is whole raw milk. And so is butter and eggs. In terms of butter and eggs, I strongly recommend trying to get those from pastured animals because then the fatty acid profile is going to be the best but, just plain, even if you can't do that, just butter and eggs would be fantastically more healthy and safe than any kind of vegetable oil.

LEA: Great. So that's great advice for Susie, the caller before break who has the wet macular, who you recommended definitely still follow suit with what her doctor has recommended for her to do. But additionally, one of the biggest things as a takeaway is get rid of those vegetable oils, add in the traditional animal fats oils, and the coconut with the saturated fats from unprocessed forms. And that's a huge, that's a huge change and a huge shift for the eyes.

DAR: Lea, should we take another caller?

LEA: We do have a little time. Yes. Patricia has been waiting very patiently on the line. Thanks for calling Dishing Up Nutrition, Patricia. You have a question today for Dr. Chris?

CALLER: I did have questions. I have been living recently in assisted livings and institution type things. And all of the food is processed food and I was wondering if there's some, I've notice that a lot of people in these facilities which are elderly, are having macular degeneration. I was trying to figure out what is this that is causing so much of this? I can see, you know, just in the population I am familiar with that is getting to be a lot of people.

DAR: So how do you make a change in that one.  That's going to be a big challenge for you.

CALLER: Yep. That's the big challenge for the population, for the communities. And how do we change that? How do they understand that?

DAR: I don't know. I guess

CALLER: It is almost impossible for them to do it.

DAR:  Well, it isn't impossible? It's a mindset, but I don't know, Dr. Chris, do you have any ideas on how do we make a change and get back to real fats versus all these process bad fats?

CHRIS:  Patricia raises an incredibly important issue because, and I think what she's saying is so true, restaurants, nursing homes, assisted living facilities, cafeterias, they're all cooking with vegetable oils. Why? Because the same reason that we got vegetable oils in the first place, they're tremendously cheap. And so, you know, it costs them a whole lot more money to cook with real butter. And you can just pour in a few cups of vegetable oil for, I mean literally just pennies or nickels, but in terms of getting them to change that, I think it's extremely hard. So when we go out to restaurants, I actually am very cautious about it. And if they're going to cook something for me where I think oil might be involved, I actually asked them if they will cook it in butter. And a lot of times you know, the waiter or waitress will go back and then they return and they give me the verdict. You know, it's either, yes, we will no problem, or sometimes they say we don't even have butter in this restaurant. And so then you have to choose something else. Like if you get just a piece of meat,  piece of chicken and vegetables that had been steamed or whatever, and then maybe you could put a pat of butter on those things because they may be able to give you a butter on the table or something like that. But yeah, I just think that even in that situation, if you understand the principle, there might be some ways to try to work around it because I doubt you're going to get them to change their policy about how that cook the food.

CALLER: Finances is the basic reason.

LEA:  Yes, finance is big. Thank you for your call, Patricia. Well, it's break time again. You are listening to Dishing Up Nutrition and next week we have a great topic called Can Stress Cause Weight Gain? Kara and Carolyn will be discussing how stressed biochemically can cause weight gain and how you can manage your weight gain with food. We'll be right back.

DAR:  Welcome back to Dishing Up Nutrition, you know, to be sure we don't run out of time, I personally want to thank Dr. Chris Knobbe for being on today and for writing his book. It's a great book. It's Ancestral Dietary Strategies to Prevent and Treat Macular Degeneration. It's not an easy read but it's readable. So, and I know you took what, four to six years on researching this topic so it took a long time and you can tell when you read the book and you know really you so much for being on our show today because we have so many callers, Chris, I think we need to have you on again, sometimes just to take callers. You know, and if people need to change their diet, that's what we do. That's our expertise. And we take you step by step through this. So it's not overwhelming.

LEA: Right. Yeah, so Dr. Knobbe, if we're using real fats like we had talked about earlier, like unrefined coconut oil or palm oil or butter or lard or unrefined olive oil, what are the nutrients that are helpful for our eyes?

DAR: That we get out of those fats, basically?

CHRIS:  Right. Well, so I think that what we're missing, and I've reviewed this in detail in the book, is that in a nutshell, we're missing the same fat-soluble vitamins that are so critical in all these other degenerative and metabolic diseases. It's vitamins A, D, E and K2. And as you know, those really have to come from animal sources in order to get these in sufficient quantities as Weston Price showed back in the 1930s that all of these traditional living peoples were consuming 10 times more of the fat-soluble vitamins than we were. And while we're on the subject, four times more water-soluble vitamins, which is all the B-vitamins and C and one and a half to 60 times more minerals than were the American people of the 1930s. And I think it's exactly the same situation with the eyes, you know, vitamins A and D are critical to to signaling and the production of these proteins.  And then vitamin K2 tends to overall activate a lot of those proteins.  These vitamins are important not only to the development of the eye but to the maintenance of the eye and they're absolutely critical to the health of the retina. So when we're missing all of these fat-soluble vitamins, which we are, especially if we're following orthodox advice in this nation to avoid eggs, avoid meat, whole milk, all those things that would have provided some of these fat soluble vitamins. We're just in a world of hurt because we're very deficient in the fat-soluble vitamins. So it's interesting to me because it's the exact same things that are leading to all these other diseases are what's leading to macular degeneration.

DAR:  Well, you know, in your book, Dr. Chris, you wrote a story about pigs and when they are lacking vitamin A. Would you just tell our listeners about that?

CHRIS:  Yeah. So in a nutshell, this was reviewed by Weston Price in his book back in the 1930s. So there was this professor Fred Hale who worked at what was a division of Texas A & M in College Station, Texas. And in the 1930s Fred Hale did this research where he deprived a mother or would-be-mother pigs of vitamin A for a few months, fed them completely vitamin A-deficient foods for several months and then allowed them to become pregnant and deprive them completely of vitamin A for another month after pregnancy began. So baby pigs, their eyes develop in the first month of gestation. So all of these pigs born to these deprived mothers were born without eyes and they had all sorts of other birth defects, but they had no eyes at all. But these baby pigs then he put them on essentially a normal diet. Gave them vitamin A. They grew up and then they were able to mate, and these pigs that had no eyes themselves were able to produce offspring, all of their litters had completely normal eyes and completely normal vision. And so, you know what physicians would say most of the time today when they see if a child was born without eyes or did they have a cleft lip or palate or something, they say, well, you know, it's just bad genetics, right? It was a genetic mutation and you know, the poor kid, whatever. Rather than say, you know, could this have been a nutrient deficiency? And in this case, this proves that these baby pigs without eyes grew up and had normal genetics themselves, given the right nutrition they could give birth to normally sighted pigs. And I think if we look at this in relation to macular degeneration, it just shows us how fantastically important vitamin A is to the development of the eye. But I think also to the maintenance of the eye health itself.

DAR: I think some of the listeners might be saying, well, what do I need to eat to get vitamin A?

CHRIS:  Right. So I think that we need to get vitamin A in the form of retinal. Retinal is the form of vitamin A that is the active form in our bodies. And so if you go into the grocery store, you see all these signs  on all these leafy greens that's a good source of vitamin A, right? And there is no vitamin A in any plant. There is no actual vitamin A. What's there os carotenoids, right? And there's something like 600 carotenoids I believe in the world, but there's about 60 of those that actually can be converted to vitamin A in our bodies. So that's alpha-carotene, beta-carotene, and beta-cryptoxanthin. Of those beta-carotene is the most prominent. But when you try to depend on carotenoids from leafy greens and vegetables for your source of vitamin A, that's a very tenuous situation. And the reason for that is because first of all, just on a genetic basis alone, half of us would be good converters of carotenoids to vitamin A, another fourth of us would be half as good as those people. So they're pretty poor at converting carotenoids to vitamin A and then the other fourth is lousy. They're terrible at converting carotenoids to vitamin A. So that's just the genetics. Then you've got gut issues. So if your microbiota and your gut is not proper or if you have hormone issues, like if you have hypothyroidism or thyroid disorders, if you have zinc deficiency, a number of other things can of affect your conversion of carotenoids to vitamin A. And so you really cannot depend on getting your vitamin A from plant foods. You need to get it from animal foods. Well, the best one is liver.  And what I recommend is three to three and a half ounces of beef liver every week. Once a week is the way to go because that will supply around 20,000 to 53,000 international units of vitamin A. We need 3000 to 5,000 IU of vitamin a per day, each one of us, and we need more than that in times of stress. Like, you know, if you have an infection or you're injured or you're pregnant, you're going to need a lot more, so you want to stock up while you stock up, you know your liver is what stores this vitamin A.

LEA:  So if people aren't in to liver, what are some others? Like butter and salmon?

CHRIS:  Yeah. So if you can't stomach liver or you just can't stand it, it makes you gag or you haven't figured out a way to consume liver, then I like cod liver oil and in this case I really like extra-virgin cod liver oil. It's the one that is where the oils are cold extracted. So it's all natural.

LEA:  Awesome. Thank you so much for being on today.

DAR: Where can people reach him?

LEA: Cureamd.org is Dr. Knobbe's foundation, so please check him out for more information.