 Hey everybody, Dr. O here. Let's talk about skin color here. So skin color primarily depends on the pigments in your skin and then circulation. So we'll cover circulation later. Let's start with pigments. We'll start with the least important one first though and that would be keratin. So keratin is going to be an orange yellow pigment that actually can accumulate in epidermal cells and in fatty tissues in the underlying dermis. This is generally not a big issue unless you consume a whole lot of beta keratin. I've seen people that eat lots of kerats that have developed a keratin, a dermia or you get an orange tint to your skin from this accumulation of beta keratin, but it's pretty minor. So when we talk about the pigments associated with skin color, the big one is melanin. So melanin is usually going to be a yellow, brown or black pigment that actually comes from the melanocytes. You see here, so melanocytes are in the stratum basal or stratum germinitibum. Very important location because if a melanocytes becomes cancerous, it can easily get into the dermis where there's blood supply. So it's the most likely type of skin cancer to mastastasize. We'll come back to that in a moment. So melanocytes actually produce the melanin and you can see here that melanin is carried in these little packets called melanosomes and that's how the melanin gets to those keratinocytes in your skin and changes their color. So your skin color, one of the first things I want to note here is skin color is determined by the rate of melanin production, not the number of melanocytes. Someone that is an albino or someone that is dark, dark black are going to have the same number of melanocytes. It is the amount of melanin being produced that determines the skin color. So a lot of that is genetic, but then also you think about tanning, your skin can respond to UV exposure by increasing the amount of melanin that's being produced. There are two primary types of melanin, so I want you to know these terms. We have umelanin and then pheomelanin. So umelanin is going to be more of the black or brown, pheomelanin is going to be more of a reddish color. So this determines your hair color as well. So I notice most of my hair is gray now, but my hair was mostly brown, but my facial hair has a much more red issue to it, which means there's more pheomelanin in my whiskers here than there are on the hair on the top of my head. So umelanin, brown, black, pheomelanin is going to be more red. All right. So what do we need it for? What is skin color? Skin color has led to just some of the most terrible things, you know, I'm clearly there's only one race and it's the human race, but skin color is nothing but an evolutionary adaptation to where you live on the globe. So when humans all lived near the equator, skin would have been very dark, which was great because if you're constantly being exposed to UV rays, if your skin isn't dark, then the UV rays are going to destroy too much folic acid that's in your blood. So folic acid is a very, very critically important B vitamin. We need it for DNA synthesis, et cetera. So folic acid is very important. So darker skin protects some of that folic acid from being destroyed. But on the flip side, if your skin is dark, it's also going to diminish the amount of vitamin D you can produce. So skin color based on where someone lives on the globe has always been this balancing act. How dark do we need to be to protect folic acid? But how light do we need to be to make sure we're getting enough vitamin D? Now if you're constantly, if you live at the equator and you're constantly being exposed to UV rays, then you can be very dark and still get plenty of vitamin D. But then as humans left the equator and traveled to the other parts of the globe, skin color would have changed. If you were, if you live in Scandinavia and you're dark black, your folic acid is very well protected, but you're going to have a harder time getting vitamin D. But this is so, but nowadays people live all over the globe and that's great. It's something to take into consideration. If you, if you have darker skin color and you're not constantly being exposed to the sun, you may want to get your vitamin D levels checked. You may want to supplement with vitamin D. What else about that? So if someone, if someone has very pale skin and lives near the equator, they can now protect themselves with sunscreen. But traditionally having pale skin being exposed to that much sun would lead to, lead the DNA damage on the flip side of something like I've already mentioned, if someone's really dark black and they live far away from the equator, then getting enough vitamin D could be, could be a problem. But anybody can live anywhere now because we have sunscreen, we can supplement with vitamin D and all these types of things. This hasn't always been the case. Look at like the Inuit, the Inuit are a long way from the equator, but their skin stayed darker. That's because they, they would have consumed vitamin D. They were eating vitamin D from all the whale blubber and seafood and those types of things. So you can, you can get vitamin D from other ways than the sun. So like it's very, very important to understand that like skin color has been a huge part of, of our, of our species history. And, and that really is too bad. It is an evolutionary adaptation to where your genes came from. How far away from the equator you lived this balancing act between, between minimizing DNA damage, protecting folic acid, but then making sure you could get enough vitamin D. That's, that's what it is. All right, I've said, I've said a lot about that. I think that's, that's plenty. As far as like skin color changing. So like if I were to go out in the summer, it takes about 10 days to really ramp up the production of melanin. So I would tan, but in those first few days, I'd be vulnerable to burning. You know, you're always vulnerable to burning even, even people with dark skin can burn. But those first few days is why it's usually why people burn more frequently early on in the summer or the first couple of times they're exposed to the sun. So it takes about 10 days to really, really ramp up the production of melanin. And then these melanocytes, the melanosomes are going to be destroyed. So skin color like that is not going to be permanent. If I tan, my tan will go away as you can probably see in some of my videos. I shoot, I shot some videos last July after vacation and I look a lot different than I do now. I've been, especially now with the quarantine, I've been inside for weeks on end. But so the, so skin color changes from the result from tanning are going to be temporary because those melanocytes, melanosomes are destroyed. They're actually swallowed up by lysosomes and degraded. So we mentioned pigments, but then your blood supply circulation will also play a role. If you have a whole bunch of blood rushing to your skin, like if you're outside, if it's hot or you're nervous or something, your skin's going to get a lot darker. If you go outside and it's cold and your blood rushes away from your skin, you're going to look more pale. If you have a severe reduction in blood flow, your blood, your skin can actually look bluish. That's going to be cyanosis, like look for blood loss, these types of things. Lastly, what can go wrong? I'm not going to cover all the types of like basal cell carcinoma in them, but I like to talk about melanoma. Melanoma would be uncontrolled growth or cancer from a melanocyte. These, they usually start from a mole, something like this. By far most fatal of the skin cancers, for reasons I mentioned before, they can metastasize so much easier because of where those cells are sitting. They can get into the blood supply, lymphatic supply and spread. So, and I'm not an oncologist, but I just want to talk about just a general recommendations. If you have moles or you're looking at your skin, what are the things they recommend to try to detect early stage melanoma? So you have A, B, C, D, E. So A is for asymmetry. So if you have an asymmetrical looking mole, borders, if the borders are irregular, something to take in consideration, color, if you have different shades of color in a mole, something to look at diameter, if they keep getting larger and they're larger than six millimeters, you know, you should have it checked out and then evolving if they're changing. If something's changing your body, that's something to take note of. So A, B, C, D, and E. And if you want to go a little further, if you're looking for nodular melanomas elevated, so if it's raised off the skin surface, firm, if it's firm to the touch, or if it's growing, any of those things, A, B, C, D, E, E, F, G, then get to the doctor and have them take a look for you, okay? All right, so that is skin color, why skin color evolved and why it's different in different parts of the planet, the production of melanin, the melanocytes and then what to look for if potentially you're developing melanoma, which I hope never happens. Okay, I hope this helps. Have a wonderful day, be blessed.