What's the deal with the sun?

21:50Emily Oster:If you're an influencer and you kind of are going to be a contrarian and say like, well, all the nerds at the ivory tower are telling you to wear sunscreen. I'm going to tell you not to. And by the way, you know, buy my product or whatever. Like there's always the grift and we should just say that. But I think we can find some other reasons that people are skeptical of sunscreen. The reason we wear, well, there's two reasons we wear sunscreen, really. One is to prevent skin cancer. And one is to prevent the solar aging. The fact that it's true, although it didn't happen to me when I was 10, the sun does age your skin.

22:25Emily Oster:And, you know, I think just I'll briefly touch on mechanism here. I think the only thing that we need to take home is that the sun, the bad stuff that comes from sunlight, not bad, the potentially damaging stuff are UVA and UVB wavelengths of light. If you go all the way back to our red light therapy episode, you'll remember that the shorter wavelengths have more energy. They can kind of do more damage, but they don't penetrate as deeply. UVB has that shorter high energy stuff that can damage DNA. and that's one of the mechanisms by which this causes cancer, whereas the UVA, which can get a little deeper, actually might be more responsible for aging, sunspots, wrinkling, and stuff like that.

23:11Emily Oster:And of course, sunscreen, we'll dig into a little bit of how sunscreen works, but sunscreen, if you're wearing a good one, will block both of these things. Both the sun and tanning beds provide the same thing. So sometimes people will talk about tanning beds being worse or better. I think that for the most part, what we are going to say here applies to using a tanning bed or being outside. Maybe there's some small differences here. Yeah. I would just think of tanning beds as the same as sun. There's a little weird stuff. There's an interesting article in Science Advances in 2025 about this that showed that the melanocyte mutation burden was higher and distributed more broadly in people who use tanning beds.

23:59Emily Oster:People who use tanning beds are also more likely to get multiple primary melanomas. So a primary cancer is like a cancer in a spot as opposed to metastatic, which has spread from somewhere else. And so multiple primaries is like getting cancer twice. These are all really kind of marginal on the edge stuff. I wouldn't like consider one being safer than the other. I will say, I don't think people should use tanning. Like if you are looking to be tan, there's a spray for that. You know, like if your goal is a physical tanning experience, like to look tan, you should just go spray tan yourself. Hey, there's also a peptide for that.

24:34There's also a peptide for that. Now you can probably get it. And so I think I would like sort of put that aside because for many people, the question is more, you know, I'm going to be outside. And then therefore, you know, should or should not, should I not protect myself? And I will say the debate on both sides is basically about cancer. So the reason that people that we think you should wear sunscreen is because of cancer. And a lot of the reason people think you shouldn't wear sunscreen is also about cancer, maybe some about endocrine disruption, but like cancer comes up on both sides of this and sometimes the same kinds of cancers.

25:13And the conversation is confused. Yeah.

25:18Emily Oster:Let me play you a clip from a typical influencer that people see online talking about the dangers of sunscreen. I am the single biggest hater of sunscreen on the planet. I stopped using sunscreen two years ago when I found out all the problems with it, and I'm never going back. For starters, the lie that we've heard is that sunscreen helps protect you from melanoma and skin cancer. Sunscreen wasn't invented until the 1930s, and I believe it wasn't brought to the United States until the mid-1940s, but it didn't get FDA approved until about 1980. Since 1980, we've seen an increase of over 700 % of melanoma cases.

25:51Hmm.

25:52Emily Oster:But I thought it was supposed to protect us from the sun. That's what all the dermatologists say. Who curated their education? Right. This guy's confused. This guy is shirtless too. Emily, is this, do we need to do this? Do we need to be recording our podcast without our shirts on? because apparently this is how you get engagement nowadays? Yeah. Are you going to – I think you should. We'll see how it goes. And then if we have to ramp up to me, we'll try that. Anyway. Okay. So the claim here is that sunscreen somehow causes skin cancer. That's confused. Yeah. I mean, so this influencer is like, oh, we started using sunscreen in the 60s and skin cancer rates have also gone up.

26:37Emily Oster:a classic ecological fallacy for the epidemiologists out there, but also a lot of reverse causality, like sunning and getting tan was not as much of a thing in the 1930s and 40s. In fact, until people could travel to exotic places and get tan and display that they were wealthy by being tan, they used to display their wealth, telegraph their wealth to others by being pale to show that they didn't have to like work in the fields and stuff. And so it was sort of the ideal of beauty to be very fair and pale and like, I've never seen the sun. And then that started to change as society changed and travel became easier.

27:15Emily Oster:People wore more sunscreen to avoid sunburns. People got more cancers because they were in the sun more often. That's really all it is. Yeah. I will also say detection rates for these things have gone up over time. And so So it is, you know, in 1850, if you got a melanoma, you just died. Nobody was like, hey, you know, let me screen you every six months for a weird mole and take it off and diagnose you. But then you're fine. You just died. And so it's a bit weird to say, you know, and probably you died from something else first anyway. So yeah. None of the chemicals in sunscreen have been associated with cancer.

27:51Emily Oster:None of them damage DNA. None of them have a mechanism by which they could cause cancer. If I'm really like waving my hands and I want to play devil's advocate, I could say, well, maybe wearing sunscreen gives you a false sense of security when you're out in the sun. And so you sort of spend more time in the sun and you don't reapply as often as you should. And maybe that's a risk factor. But you can't really blame the sunscreen for that, right? Like it doesn't cause cancer. And we have a fair amount of data that wearing sunscreen reliably reduces cancer. So I think the best data comes from Australia.

28:26So there's a trial published in the late 1990s, 1 ,600 Australians. They were randomized to either daily SPF 15 or discretionary use, which just meant use it whenever you want. Since people don't do things, they use less over a period of about five years. There was a 38 % lower rate of, I never know how to say these words.

28:49Emily Oster:Squamous cell carcinoma. squamous cell carcinoma over eight years of follow-up. And there is a non-significant, but sizable reduction in the number of invasive melanomas. Melanomas is fairly uncommon. So there were only three invasive melanomas in the sunscreen group and 11 in the other group. And so that's not really enough to be statistically confident, but it is meaningful. I think that's our best. I think that's our best randomized data. It's a randomized trial. It wasn't even that much SPF. I mean, 15 is kind of on the low end of what we would probably use today. And it's good. The observational data, like influencers will pull out studies that you can find studies that show people use sunscreen have lower rates of cancer, studies that show that people use sunscreen have higher rates of skin cancers.

29:42So much of this is what we call confounding by

29:45Emily Oster:indication, right? Which is that people who are at higher risk use more sunscreen, right? Because it's not randomized. You see a similar thing. I'm almost like hesitant to say it. People who take statins have a higher risk of heart attack overall than the general population of people who don't take statins because people who take statins take them for a reason because they're at higher risk of heart disease. They're older, they have diabetes, they have high cholesterol. Whereas an 18-year-old who's perfectly healthy doesn't take a statin and is unlikely to have a heart attack. So this is all over the observational literature, which is why you need randomized trials.

30:20Emily Oster:We have one. Sunscreen reduces the risk of skin cancer. We call that reverse causality, but like in economics, this thing. I mean, this is just like an interesting, like there's different words for this. We call it reverse causality, which I like better because I think it's easier to say than confounding my indication and it makes more sense. Well, cheerfully withdrawn. All right. There are multiple kinds of sunscreen that one could use. There is mineral sunscreen. This is the sunscreen that makes your face white. It blocks with zinc or titanium dioxide. And you too can look like an 18th century consumptive.

31:01Queen Elizabeth covered her face in lead and you can cover your face in zinc oxide and achieve the same activity without the facial pitting.

31:10Emily Oster:Yeah. I was surprised actually to find, I didn't actually know this, zinc oxide has broader spectrum coverage. So the way these work, by the way, is just, it's a physical barrier. Like the UV reflects off the tiny particles of zinc or titanium and just reflects into a way towards someone else. Zinc does that both for UVA and UVB, whereas titanium is really UVB focused. And so some dermatologists will recommend to make sure that if you're using titanium alone, like you want to be using something else for UVA, particularly because you don't want that skin aging effects. For those of you who don't want to look like 18th century consumptives, these nanoparticle formulations that they have now are a little less white.

31:55Emily Oster:I don't know if you've tried them, Emily. They look okay. They're okay. And they seem to, and medically speaking, they're just as good as the other kinds. There are also chemical sunscreens, and that is anything you're using in a spray. There are other chemical sunscreens which are using chemicals to block the UVA and UVB light. They do not turn your face white. Some people are afraid of these due to concerns about endocrine disruption from some of the chemicals that are used in this. I will say that if you feed a rat very, very high doses of some of the chemicals in these sunscreens over their whole lifetime, it is not good for them and their reproductive system.

32:37But the kinds of level of exposure that you have as a person using this sunscreen is very different than if you are a rat who's primarily eating it. and in fact people have looked carefully at you know how much would you have to use sunscreen like over your whole life cycle to get to this exposure and it's like not feasible so I would say if chemical sunscreen is the thing that is easier for you or more acceptable you should use that and if you like the white stuff that's also great and if you want to just wear a lot of clothing instead that is also okay but less feasible for most people and especially for kids

33:16Emily Oster:Totally agree. Whatever will make it easier for you to use. For the chemical sunscreens, those chemicals also have different levels of UVA and UVB protection. The FDA has an official labeling for stuff that covers both, and it's broad spectrum. So you do want a sunscreen that has that broad spectrum coverage on it that's legally regulated. Also, you don't need SPF 3 billion. So they will sell very expensive SPFs like SPF 100. Does it really make any sense given what I understand to be what this means? But SPF 30 is the American Dermatological Society says SPF 30 or higher. So 30, 50, you do not have to have 99, which is expensive.

34:02Emily Oster:There is one part of sun hitting your skin that I debated putting in this episode, Emily, but I think we just have to talk about it. And that is, should we be sunning our perineums? Let me play you a clip from Mr. Health Nut. Oh, this is a good one. Okay, here we are guys. You guys ask about the butthole sunning all the time. And this is another one of my practices. I don't always talk about it. But it's well known that your sphincter or your butthole is one of the most sensitive or thin mucous membranes in the body. 30 seconds of sun on the butthole is like eight hours of sun outside with your clothes on.

34:51And so let's face it, the sun is the source of all energy. And so you're getting that sunlight up into the channels of the body. You're giving yourself a nice energetic electrical butt plug. For men, sun on your testicles or naked sun is good for testosterone boosting. This is just energy for the soul. My favorite part of that clip, Harry, is when he says he doesn't – people don't talk about it all the time. It's like that's true. That's true. We don't talk about this all the time.

35:23Emily Oster:Can you describe what you're watching for people who are listening to this in audio format? There's a man. He's both shirtless and pantsless, although you can't see too much. And his legs are over his head and it is obvious that he is exposing his butthole to the sun while explaining the benefits of doing so. This is in the zeitgeist in no small part because Tucker Carlson himself tried this. He had some documentary on being a man or manliness in America and somehow this incredibly unmanly thing. I look at this video and I'm like, this just does not scream macho to me. Apparently boosts your testosterone or something like that.

36:10Yeah. I should say your butthole and your perineum are actually not the same thing. So first of all, that's not the scientific word for your anus, but the perineum is the area between your either vagina or your scrotum and your butthole. So I guess all of that area could be sunned, but don't do it. Because you'll get sunburned. That's a terrible way to get a terrible, painful sunburn in a very uncomfortable area.

36:39Emily Oster:Absolutely. First of all, this doesn't work. There is some data that human testosterone levels peak in late summer, early autumn, but that has nothing to do with your perineum, and it probably doesn't even have anything to do with sun exposure. There's multiple factors that change testosterone levels, so that's nothing. And there is some risk here. So people with psoriasis can get UV therapy, so ultraviolet lights to treat the psoriasis. UV light is immunosuppressive to some extent. That's one of the reasons that cancers can develop with excessive UV exposure. But for psoriasis, you want to suppress the immune system.

37:15Emily Oster:And when they first started doing this, they found that people getting UVA and B therapy for psoriasis had a fourfold increase in genital tumors. And that was because the skin around the genitals is very thin, so that high energy UVB can penetrate to more important stuff than it can in the other parts of your body. And so now the guideline recommendations for people getting that therapy, even whole body UVA, UVB for psoriasis, is to specifically cover the genital area, the perineum. So don't do this. Okay. Should we take a break? I feel like we need a break. We're going to take a break. If you need to go sign your butthole, this is a great time.

37:56And then come back and we'll talk about vitamin D. If you're someone who's tracking your sleep, your steps, and your macros, then you already know that what you eat is kind of everything. You should also know that Sprouts Farmer's Market can help make eating for longevity easier. Sprouts has all the high-quality, nutrient-dense organic foods and cutting-edge supplements you need. So whether you're focused on protein, gut health, or optimizing how you feel day-to-day, it's all there. And here's what no other grocery store can offer. An in-store wellness expert to help you find exactly what you need.

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38:37Emily Oster:My name is Arnold Bogarty, and prior to me enrolling in Rasmussen to become a nurse, I spent 16 years in the military, 12 in Special Forces as an Army Green Beret, and I was recommended to Rasmussen by a former student. She said she loved the culture. It was a family atmosphere. I went to visit the campus. The facilities were amazing. I knew before I left that that was the school that I was going to attend. Rasmussen University. Are you ready to be your own hero online and on campus? Learn more at rasmussen.edu.

39:10Emily Oster:Zach, nice vacation spot, but without T-Mobile 5G home internet, I feel so cut off. It's scary. Relax. Just breathe in the woodsy woodsy-ness. Zach! Don't open it. It's a monster. I just know it. Buddy, it's just our DoorDash driver delivering our T-Mobile 5G home internet. Here you go, guys. Thanks. Look, Donald, now you can get the fastest 5G home internet with same-day delivery powered by DoorDash. And it's easy to set up. See? Nothing to be afraid of. We're saved! It's scary how easy it is. Get T-Mobile 5G home internet delivered the same day. Powered by DoorDash. Just$35 a month with auto pay and a voice line.

39:55Emily Oster:Plus taxes and fees. Same day delivery for most internet eligible customers. See if it's an option during checkout. Fastest according to UCLA Speed Test based on speed test intelligence data second half 2025. All rights reserved. Welcome back. We are going to turn to vitamin D and whether the need for more vitamin D is part of why you should be exposed to the sun. Let me set the stage here by saying there are many vitamins, A, C, E, a bunch of different B vitamins. Most of these you get through your food. Vitamin D is one that you get some through your food, but also through exposure to the sun.

40:42Like other vitamins, if you do not have enough of this, it's very bad. So vitamins are, in general, substances that our body cannot produce on its own, so we must be getting from some outside source. Like extensive vitamin D deficiency is associated with rickets in kids. with kind of bone decay, you need vitamin D to support your bone. But you basically can't get enough of it through food. So most foods don't have very much at all. Your milk is fortified with that. But most people in the US are not getting anything close to the appropriate amount of vitamin D in food. And so they have to get it through the sun.

41:25Okay. How does it happen? Science Perry, how do you get vitamin D through the sun? It involves the kidneys. So I'm going to give this to you.

41:33Emily Oster:Yeah, it does. So you have in your skin a substance called 7-D hydrocholesterol, which is a cholesterol derivative, and UVB converts that to vitamin D3. So you've probably seen D3 supplements in the GNC or CVS or whatever. That's what it is. Vitamin D3 is not active. It has no physiologic effects, but it is a substrate that gets converted by the liver to 25-hydroxy vitamin D. That is also not active. You can get a prescription for that. This is called ergocalciferol, but it's generally not sold in stores. That 25-vitamin D goes to the kidneys and becomes 125-hydroxyl vitamin D. And that, and only that, is the biologically active form of vitamin D.

42:26Emily Oster:There's a prescription form of that as well called calcitriol, which is very expensive and has a lot of side effects. But basically, there's a lot of processes in your body that are designed to get you to vitamin D, and it all starts with UVB exposure. But I think what will surprise people is how much vitamin D you get from a little bit of sunlight. So the recommended daily intake for vitamin D varies. 200 to 400 international units is sort of typical. And you'll see supplements ranging from like 1 ,000 to 2 ,000 international units per day, vitamin D supplements. If you had UVB exposure for 20 minutes to your whole body, so imagine 20 minutes on the beach, if you're a light-skinned individual, and this is an important consideration, that produces approximately 10 ,000 international units of D3.

43:22Emily Oster:So about 10 times the dose you'd get from taking a vitamin. That's 20 minutes. It is also, I think, important to say at this point that you cannot overdose on vitamin D through the sun. So if you were outside for a very long time, like putting aside the sunburn risk and you say you were outside for five hours, and so it's going to be many bajillion units of vitamin D, that does not cause you to overdose. Whereas taking that amount in a supplement would actually be quite dangerous. Thank you for saying that. Yes. The sun degrades vitamin D3 in the skin. So as it's making it, if there's a ton there, it'll degrade and it puts the brakes on automatically.

44:08Emily Oster:But It ingested vitamin D3 is its own thing. People can absolutely overdose on this stuff. You can get something called milk alkali syndrome. Fascinating. You can get very high calcium levels, which can cause a lot of things, kidney damage, coma, arrhythmias, bad stuff. I think, though, the reason vitamin D comes up a lot is that we have a slew of studies linking low vitamin D level, measured vitamin D. And I'll just say, typically when people are measuring vitamin D in the blood, they're often measuring 25 vitamin D, that liver one before it gets to the kidney. It's just an easier test to run than the real vitamin D.

44:51Emily Oster:It's fine. But we have a slew of studies linking low vitamin D levels to a variety of diseases. And I listed a few. So low vitamin D level increases the risk of cancer. Low vitamin D level increases the risk of cardiovascular disease. The low vitamin D level increases the risk of diabetes. Low vitamin D increases the risk of falls, COVID, all-cause mortality. Looking at all that observational data, you'd be like, oh my God, vitamin D is the most important thing in the world. But Emily, we don't like observational data. What are the randomized trials of vitamin D supplementation show us? The randomized trials of vitamin D supplementation show us that but there's nothing.

45:35So there are actually a large number of randomized trials on all of the outcomes that you have listed. Some of it is the same trial looking at, and these trials are big, you know, 25, 26 ,000 people, true placebo control trials. And they just don't show anything. They just show no differences. When you supplement people with vitamin D, it doesn't look any different. Nothing different happens than if they weren't supplemented with vitamin D. And this is because the observational data is driven by bias, by the fact that the people who are taking the vitamin D are different from the people who don't take the vitamin D.

46:18And in fact, like before I get off my high horse about this, we have for many years been telling people to take vitamin D. Like vitamin D is good for you. Take vitamin D to prevent cancer. And so not only Is there this baseline, just like people who take more vitamins tend to be positively selected in various ways. But over time, we've like made that worse with our advice. So we tell people take vitamin D and the people who take the vitamin D are also the people who are doing all of the other things. And so the problem has gotten like worse and worse and worse over time. About a half of Americans take a vitamin D supplement now.

46:53And if you look at what half it is, it's also the half that's exercising and eating vegetables and doing other things that not smoking. And so it just it's just a classic case where like the observational data is super is super misleading.

47:10Emily Oster:Even people even if you exclude people who are supplementing at all, you do find observationally that lower level like blood level of vitamin D associates with all these bad outcomes. But the way I often describe it is that vitamin D, your vitamin D level, if you're getting your vitamin D measured, it's very much a lifestyle biomarker. Like if you are the type of person who goes outside and gets sun and exercises and touches grass, like you're going to have, and it's a varied diet, right? With multiple sources of vitamin D in it, you're going to have a higher vitamin D level. Conversely, if you're a person who is sick from other things, who has nutritional deficiencies, who isn't getting outside and getting exercise, you're going to have a low vitamin D level.

47:55Emily Oster:It is a very nice marker of kind of overall health, but that doesn't necessarily mean that making the marker look better makes your health look better. It's the canary in the coal mine and bringing in a better canary or whatever doesn't fix the coal mine. That's a bit of a tortured analogy. Sorry, Canaries, you're all dying. I see where you were going with that. Yeah. So from the perspective of the sun, I will say, like, you know, you are probably getting enough vitamin D from your exposure to the sun already. And you don't need to either stand outside more in the sun for more vitamin D, nor do you need to take a vitamin D supplement.

48:33Emily Oster:Yeah, it is a bit harder, of course, in the winter and in certain climates where the sun doesn't shine as much. And it is certainly harder for darker skinned individuals. That melanin that protects the DNA in your cells from UV causing mutations also decreases the ability of UVB to help synthesize vitamin D. And so if you are darker skinned, there's more rationale for focusing on dietary intake of vitamin D. I'm still not very pro supplement of vitamin D just because even in the randomized trials, we don't see a signal across any skin tone for benefit, by and large. Totally right. I'm a negative on vitamin D supplements, even though many people are always telling me to take them.

49:19But I don't.

49:20Emily Oster:Don't take them. Don't do it. All right. So the sun necessary for your vitamin D, but you don't need more of it. Sunscreen, very important. And there are other ways in which we have evolved to like the sun. In particular, it makes us happy. People like to go outside and be in the sun. That's nice. Yeah. I mean, and we see this, well, we see it in observational data where, you know, people who spend more time outside have a lower risk of depression. Is that causal? I don't know. But we do have evidence on seasonal affective disorder, which responds to light therapy. So I think there's a sort of clear, randomized trial that supports a mechanism that light exposure makes us happier.

50:11Seasonal affective disorder is actually a big problem in a lot of these countries where it's really dark all the time. Yeah.

50:17Emily Oster:And it's interesting. It does not appear to be vitamin D mediated. So it's not that your vitamin D gets low and that's what causes sadness because vitamin desupplementation does not improve seasonal affective disorder. But the blue light therapy does. That's clear, as you say, from randomized trials. A lot of the mechanism apparently is circadian sleep disruption. And the blue light therapy is done early in the morning to sort of reset your circadian clock. And if there's any theme of the Wellness Actually podcast, it is that sleep is the most important thing and is tied to everything else. And so I think this is yet another example of that.

50:53Yeah. Sleep is very important.

50:55Emily Oster:I found a couple of other weird sun benefits that I'm curious what you think about, Emily. One is some fairly consistent links between low childhood sun exposure and subsequent multiple sclerosis. So multiple sclerosis is clearly diagnosed more in the northern latitudes And this is not just a rich country, poor country thing, because even across, for example, the United States, like the further north you are, the higher the risk of multiple sclerosis is. I don't have a great mechanism for why this would be, but like, it's not just one or two studies that have found this link. And I don't know.

51:42Emily Oster:What do you think? Do you think that there's an MS sunlight thing? It's a little hard to tell from the studies that are on this. Most of these are what's called a case control study. And so they identify, you know, because multiple sclerosis is not common. I mean, it's not vanishingly rare, but it's not like, it's not a common thing. So you don't see it that much in these large population studies. The way these studies often work is they will take a set of people who have the diagnosis and then find some other people without the diagnosis and, you know, compare them on feature, like questions they ask them, survey questions, other characteristics.

52:20That kind of study has all of the problems of basic observational data that these groups may differ in many other ways. It also has a problem that they differ in how you select them. And you're asking about stuff often that happened in the past. It's not a very strong empirical approach. It's sometimes the only approach that we have. And so I don't want to like say we should never look at this, but it feels as an approach, like something that would generate a hypothesis rather than prove one. And so this sort of, this feels like there's probably something more clever someone could do to try to get more of an answer here.

53:00We don't understand that much about MS and what drives people. It seems clear that there's genetic risks, but also the epigenetic issues and other things that happen. So it's an interesting research area. My guess is that sun exposure will not turn out to be the most important feature here.

53:18Emily Oster:Fair enough. If it gives people motivation to get their kids outside in the sun, all for the good, but make sure they're wearing their sunscreen. There is actually some better evidence that outdoor time reduces myopia. That's probably not just about the sun, but about being outside. Oh, sure. And some of that is from randomized data. Yeah, yeah, yeah. Yeah, I guess it turns out that, I mean, I guess our moms were right, which is like sitting too close to the TV is going to ruin your eyesight, right? Like when you're outside, you're forced to, what is it, accommodate your pupils to distance, which flexes those muscles a little bit.

53:57Right. Something like that. Yes. Anyway, it's good to go outside. Yeah, be outside. That's another theme of the wellness. Go outside and then also go to sleep, but not outside.

54:05Emily Oster:Right. Right. All right, Emily. I think it's time to decide whether this sun thing is all it's cooked up to be. Smash or pass the sun? I'm a smash. I mean, you know, it has its limitations, but I would say on the whole, I'm pleased that we have the sun around and I'm going to keep, I like to keep it. I agree. Smash. The sun is one of my top five stars in the galaxy. What is your second favorite star? Is it Alpha Centauri? Yeah. It's Rigel, actually, because that's where the pleasure planet is in Star Trek. That's for Tamar's husband. I will say I'm going to pass vitamin D supplements because we also talked about that.

54:58and I'm going to smash sunscreen. What about you?

55:03Emily Oster:I will pass on vitamin D supplementation and smash sunscreen. Yes. Amazing. All right, that's it for The Sun. Your mailback question of the week after the break. If you're someone who's tracking your sleep, your steps, and your macros, then you already know that what you eat is kind of everything. You should also know that Sprouts Farmer's Market can help make eating for longevity easier. Sprouts has all the high-quality, nutrient-dense organic foods and cutting-edge supplements you need. So whether you're focused on protein, gut health, or optimizing how you feel day-to-day, it's all there. And here's what no other grocery store can offer.

55:41An in-store wellness expert to help you find exactly what you need. So whether you're after longevity or on any other health journey, it's easier at Sprouts Farmer's Market.

55:51Emily Oster:I have been with Rasmussen University since 2013, all virtual. All of my professors throughout the entire journey have been nothing but supportive of making me reach my dreams. Rasmussen professors, they want to see you grow so that you can be what you went to school to be. I'm so thankful for Rasmussen University for being able to make it so easy and seamless. Rasmussen University. Find your seat and start now at rasmussen.edu. Hey, Donald. Really flying on that treadmill. I'm trying to run as fast as T-Mobile 5G home internet, Zach. Well, you better pick it up, because now T-Mobile has the fastest 5G home internet, according to Ookla Speedtest.

56:33Emily Oster:Really? How's this? T-Mobile's faster than that, bud, and it's still just$35 a month. Speed up! No! Plus, they've got a five-year price guarantee. Come on! Faster! How can I go any faster? Channel the speed of T-Mobile 5G home internet. Think 100-meter dash fast. Think drag racing fast. Think speed skating fast. Now let's bump up your speed a notch. Hey, whoa, whoa, that's too fast! You'll be all right, just walk it off. Get on the fast track. T-Mobile now has the fastest 5G home internet. And it still starts at just$35 a month with auto pay and a voice line. Plus a five-year price guarantee. Plus taxes and fees.

57:13Emily Oster:Fastest according to Ooglow Speedtest Intelligence. Date of second half, 2025. All rights reserved. Guaranteed for monthly price of 5G internet data on eligible plans. Find exclusions and details at T-Mobile.com. All right, let's move to our question of the week. And if you have a question, you can go to wellnessactually.fm and leave us a recording and we will try to answer it. All right, this week, here's a question. Hi, Emily and Jerry. Settle a bet between my husband and me. Which organs can you live without? Thanks. This is such a fun question. It's the kidney, right? You only need one of those.

57:49Emily Oster:I know they're your favorite, but it's not important. Oh, well, if we're saying we can only take out one, then you can definitely take out one lung. That's fine. You can take out half a liver, basically. Oh, sure. Yeah, yeah, yeah. Okay. So I only need one of my lungs. Come on. I was, yeah. I mean, I'm not saying it's going to be great, but you're fine. You can take out people's whole lung all the time for cancer and stuff like that. I thought this question was the whole organ system, in which case I was going to say kidney because of dialysis. Because we don't really have a dial. So kidneys clean the blood and dialysis can kind of take over that for people who have end stage kidney disease, which you would have if both your kidneys were removed.

58:35Emily Oster:It's not the greatest thing in the world. You're getting four hours of dialysis three times a week, but you'd stay alive. And we don't really have that. I'm trying to think. We don't really have that for anything else. I mean, I guess - No, what about your reproductive organs? We could take out your uterus, your ovaries, testes. Yep. Who needs them? No problem. Not using them all the time. Yep. Our producer, Tamar, says gallbladder. Sure, you can remove that. Is that an organ? Appendix? Is that an organ? Yeah, I don't think I would call it appendix. Or just like a useless end piece. An organ. Let's see.

59:08Emily Oster:Brain, you probably need - You need that. You know - Colon? Could you remove your whole colon? Yeah, you can take out your whole colon. That's done.

59:22Emily Oster:Spleen, absolutely. You can do without a spleen. Wow, we can remove a lot. We can take a lot of that. Why did you become a doctor? It's a minimal viable product for humanity. Let me ask you, Perry. Why did you choose to be a doctor specializing in one of the organs we don't need? Why didn't you pick an organ that is necessary? Oh, that does hurt a little bit. But it's a good point. Do you know why? It's because the kidneys are one of the few organs where you can very easily measure the input, which is blood, the output, which is urine, and infer the miracle that is going on inside. Try that with anything, any other organ.

1:00:00Emily Oster:It's very difficult. Spoken like a true lover of kidneys in the human. All right. So it turns out we don't need many of our organs. But yet somehow, let's just say there aren't, there's very few organs other than maybe your reproductive organs where removing them, even then probably those, where removing them like would not result in some change to how you would have to behave. Yeah, yeah, yeah. They're there for a reason. They're there for a reason. Evolution didn't, except for the appendix, which is a waste of time, most of our stuff is useful. Okay, that's it. Join us next week when we will ask, what's the deal with gluten?

1:00:44Wellness Actually is produced in association with iHeart Media. Our senior producer is Tamar Abishai. Our executive producer at iHeart is Jennifer Bassett. Our theme music is by Eric Deutsch. And our content is for educational purposes only.

1:00:59Emily Oster:If you like the show, help other people find us. Leave a rating and review on Apple Podcasts or your podcatcher of choice. And help us spread the word about the show. You can follow us on Instagram at wellnessactuallypod. And don't forget, we want to hear from you. Head over to wellnessactually.fm and leave us a question for our mailbag or suggest a topic for a future show. We'll let the influencers have the last word. The sun is a mass of incandescent gas, a gigantic nuclear furnace where hydrogen is fused into helium at temperatures of millions of degrees.

1:01:40If you're someone who's tracking your sleep, your steps, and your macros, then you already know that what you eat is kind of everything.

1:01:47Emily Oster:You should also know that Sprouts Farmers Market can help make eating for longevity easier. Sprouts has all the high-quality, nutrient-dense organic foods and cutting-edge supplements you need. So whether you're focused on protein, gut health, or optimizing how you feel day-to-day, it's all there. And here's what no other grocery store can offer, an in-store wellness expert to help you find exactly what you need. So whether you're after longevity or on any other health journey, it's easier at Sprouts Farmer's Market. I think something that makes me well-studied to be a nurse is my empathy. Growing up with a big family, I think I've always kind of been a caregiver.

1:02:20Emily Oster:When you care give, you get to know the family and the patient and you get really close. And Rasmussen University, they did a very, very good job of giving us the resources that we need. So just being able to apply the knowledge that I've retained to my daily life has been so amazing. Learn more at rasmussen.edu. The Hulu original series Furious is now streaming on Hulu and Hulu on Disney+. Starring Emmy Rosam as Alice Black, Furious follows a rookie FBI agent on the hunt for Catherine, played by Lola Pettycrew, a mysterious and calculating female serial killer. While Alice upholds justice, Catherine kills for it, terrorizing the rich and powerful men of New York in her pursuit of vengeance.

1:03:06With secrets that change everything, Alice discovers there's a thin line between Hunter and Prey. Watch the Hulu original series, Furious. Now streaming on Hulu and Hulu on Disney Plus for bundle subscribers. Terms apply. This is an iHeart Podcast. Guaranteed human.