Latest / So That's Why / Why Do Some People Tan While Others Don't?

Transcript

Why Do Some People Tan While Others Don't? · So That's Why

• 0:05
  Jen: Welcome to the So That's Why podcast, where we unpack the
• 0:07
  science behind everyday questions.
• 0:09
  I'm Jen.
• 0:10
  Chris: I'm Chris.
• 0:11
  Jamie: And I'm Jamie.
• 0:12
  Jen: Okay.
• 0:12
  So picture two people lying on the same beach, the same hour, under the same sun.
• 0:19
  One gets up golden brown.
• 0:21
  The other one gets rough- gets up, and they are roughly the color of a tomato.
• 0:27
  So why do some people tan while others don't?
• 0:31
  Jamie: I'll be up front.
• 0:32
  I'm one of the annoying ones.
• 0:33
  I go brown just by walking out of the car.
• 0:35
  Chris, though, I think you're a tomato in this scenario, aren't you?
• 0:39
  Chris: Well, I've been called worse, let's be honest.
• 0:40
  But no, you- you're absolutely right, yeah.
• 0:42
  Two minutes of weak British sunshine, and I'm lightly poached.
• 0:46
  And here's the part that most people don't understand enough.
• 0:48
  So whether you can tan at all is really not about the sun or how hard
• 0:54
  you try, it's down to your genes, and it's settled before you were even born
• 0:58
  Jen: Yeah, and that's the bit that surprised me the most because we
• 1:01
  treat tanning like a skill that you build up over a summer, but
• 1:06
  you either can do it or you can't, and trying harder changes nothing.
• 1:13
  But we'll get to how that works later.
• 1:15
  Jamie: Before we do, can I check something?
• 1:17
  I've heard people s- something that I've heard people swear by for
• 1:20
  years, the idea of a base tan, the idea being that some people go on
• 1:24
  a sunbed before they go on holiday-
• 1:26
  Jen: Mm
• 1:26
  … Jamie: so that they don't burn when they're out on their holiday.
• 1:28
  Is, is there anything in that?
• 1:30
  Jen: Well, it's worth being, you know, fair to it because it isn't a
• 1:34
  total myth, but it might as well be.
• 1:37
  So a tan, it does add a little bit of protection.
• 1:41
  It's just nowhere near as much as people imagine.
• 1:44
  Chris: Yeah, you're absolutely right, and in sun protection we talk about
• 1:47
  SPF, which is the sun protection factor.
• 1:50
  So a tan is worth an SPF of two to four.
• 1:54
  Jen: Mm.
• 1:55
  Chris: So a tanned you therefore, um, being two to four times better
• 1:59
  protected than an untanned you.
• 2:02
  But let's be honest, the lowest SPF that anyone would ever sensibly recommend as
• 2:06
  meaningful is about 15 or, or higher.
• 2:08
  So SPF two to four is pointless.
• 2:11
  It's like holding a single sheet of paper over your head in a
• 2:14
  downpour and hoping for the best.
• 2:15
  Jamie: So you'll still get soaked, but you feel like you've tried.
• 2:18
  Jen: Yeah.
• 2:18
  Absolutely.
• 2:19
  Pretty much.
• 2:20
  I remember growing up in the '80s and they sold factor two and factor four in shops.
• 2:24
  Do you remember that?
• 2:25
  I
• 2:25
  Chris: do.
• 2:25
  It was like in carrot oil or olive oil-
• 2:28
  Jen: Yeah
• 2:28
  … Chris: so people literally kind of- Yeah Fried … frying themselves in the sun.
• 2:31
  It's, you know-
• 2:32
  Jen: Yeah, don't see that now … it's
• 2:33
  Chris: scary.
• 2:34
  Jen: So the real question is why some of us make a decent
• 2:37
  tan and others just go red.
• 2:39
  That
• 2:39
  Chris: is the question, and this all comes down to pigmentation.
• 2:44
  So to start things off for the fact fans out there- … did you know that whatever
• 2:48
  your skin tone, so, um, you have roughly the same density of pigment making
• 2:53
  cells in your skin, and it's about 1,200 cells per square millimeter of skin?
• 2:59
  So that's whether your skin is very fair or very dark.
• 3:02
  Jamie: So hang on.
• 3:03
  The same number for everyone.
• 3:04
  So it isn't that darker skin simply has more of these pigment cells.
• 3:08
  Chris: That's right.
• 3:09
  Jen: Yeah, and that's an assumption that, you know, almost everybody would
• 3:13
  make, but it actually, it's wrong because the same number, we all have
• 3:18
  the same number of pigment factories.
• 3:20
  Mm. The difference is what those factories are making.
• 3:23
  Chris: Exactly, and the pigment we're talking about here is melanin.
• 3:26
  So melanin is the skin's own sunscreen, but here's the important
• 3:30
  bit, that skin doesn't make more melanin because sunshine is healthy.
• 3:35
  It's making more melanin because the ultraviolet light has triggered a, a
• 3:38
  protective response after the event.
• 3:41
  Jamie: So the tan isn't the protection itself.
• 3:43
  It's the skin putting more protection in place after it's been exposed.
• 3:48
  Offering only very marginal extra protection.
• 3:50
  Chris: Mm-hmm.
• 3:50
  Jen: Yeah, and that's essentially what a tan is.
• 3:53
  So the UV damages the skin, and the tan is like the skin toughening up
• 3:58
  in response, which is why a tan, as it, you know, as nice as it might
• 4:03
  look, is never a sign of health.
• 4:05
  It's a sign that the skin's already taken a hit.
• 4:08
  Chris: And it's so important, isn't it, because that's the fundamental
• 4:10
  point that gets misunderstood.
• 4:12
  A tan is a repair job.
• 4:13
  It's not a glow of good health.
• 4:16
  Jamie: So every holiday photo where somebody says, "Look how healthy I look-
• 4:19
  "… is technically a close-up of skin damage.
• 4:21
  Chris: Yeah.
• 4:21
  Jen: Yeah, it is, but let's talk about the damage itself, 'cause
• 4:25
  it's quite specific, isn't it?
• 4:27
  And Chris, we know that this is your speciality area.
• 4:30
  Chris: It is.
• 4:30
  I've done a lot in the area of sun protection over the years, and,
• 4:33
  uh, I do feel passionate about it because of misinformation and
• 4:36
  just poor campaigns out there.
• 4:37
  Mm-hmm.
• 4:38
  So if we start with the what's going on chemistry-wise.
• 4:41
  So ultraviolet rays within sunlight have different wavelengths.
• 4:45
  The longer wavelengths are known as UVA, with the more
• 4:49
  medium wavelengths known as UVB.
• 4:51
  So UVA penetrates deep into the skin, with UVB penetrating into the outermost
• 4:57
  layers of the skin and triggering most of the burning and tanning that we see.
• 5:00
  Jamie: So the same light that burns Chris is the light that tans me.
• 5:04
  It just lands differently depending on who's underneath it.
• 5:07
  Jen: Yeah, and that's the key to the whole thing.
• 5:09
  So what UVB does is it causes damage inside your skin cells, and the cell
• 5:15
  notices, and then there's a protect- there's a protein called p53, which
• 5:20
  is also nicknamed the guardian of the genome, which I think is such a cool name.
• 5:25
  Spots it, and then that raises the alarm.
• 5:27
  Chris: Yeah, Matt'd be naming a new TV show The Guardian
• 5:30
  of the Genome, wouldn't he?
• 5:30
  Jen: Yeah, yeah.
• 5:31
  Chris: Volume three.
• 5:33
  Um, and that alarm that you mentioned is the signal that tells the pigment
• 5:36
  cells to start making more melanin, uh, to try and fend off that UV damage.
• 5:40
  But however, as we said earlier, the damage always comes first,
• 5:42
  so it's after the event.
• 5:44
  Jen: Mm-hmm.
• 5:44
  Jamie: So the tan literally can't happen unless the DNA gets damaged first.
• 5:48
  The damage is the thing that places the order for new melanin.
• 5:52
  Jen: And here's the precise bit because people muddle it.
• 5:54
  So tanning and burning aren't one thing at different strengths.
• 5:58
  They're two completely different processes.
• 6:00
  So a burn is your skin being injured and inflamed, while a tan
• 6:05
  is something active and protective.
• 6:07
  Your skin's manufacturing pigment, albeit in response to damage.
• 6:11
  So whether you can pull off that second one at all comes down to your
• 6:16
  genes, not to how much sun you get.
• 6:19
  Chris: That's right, and here's the catch, even for those who can do it and can tan.
• 6:22
  Mm. So a proper protective tan takes a couple of days to come in, uh, and
• 6:27
  come up fully, so it does nothing for the sun you're getting today.
• 6:30
  And whatever your, uh, you build in terms of that tan, you don't keep.
• 6:35
  Uh, plus it's only offering that very small amount of protection
• 6:37
  anyways we've already covered.
• 6:38
  Jen: Mm.
• 6:39
  Jamie: So it's protection that turns up late and leaves early.
• 6:41
  Classic.
• 6:42
  Yeah.
• 6:43
  Jen: Pretty much.
• 6:43
  Yeah.
• 6:44
  And your skin replaces itself anyway, doesn't it, every four weeks.
• 6:47
  So those pigmented cells that tan, those cells get pushed up, shed, and swapped for
• 6:53
  fresh pale ones, which is why a tan fades and why it's never lasting protection.
• 6:59
  Jamie: Okay, but here's what I still don't get.
• 7:01
  I go brown just by standing near a window.
• 7:04
  Chris goes the color of a London bus.
• 7:06
  Same number of cells, same alarm, so why the difference?
• 7:10
  Chris: Yeah, I really do go the color of a London bus, actually.
• 7:12
  It's quite, quite depressing really.
• 7:13
  But anyway, um, so this comes down to the most critical point when
• 7:17
  it comes to melanin, that there isn't one melanin, there are two.
• 7:20
  There is eumelanin and pheomelanin.
• 7:23
  So eumelanin is the darker one, uh, it's darker in color, whereas
• 7:27
  pheomelanin is more reddish to yellow.
• 7:29
  So they behave completely differently, and if you imagine your, um, pigment
• 7:34
  cells as kind of little printing shops, the question isn't how many you've got,
• 7:39
  it's which melanin cartridges there are.
• 7:42
  Jamie: Eumelanin and pheomelanin.
• 7:44
  One, one might almost say Jamie melanin and Chris melanin.
• 7:47
  Catchy.
• 7:48
  Yeah.
• 7:48
  The dark one and the red one.
• 7:50
  Chris: That's so harsh, isn't it?
• 7:51
  But fair.
• 7:52
  Jen: It's nice that I'm escaping this all.
• 7:55
  So yeah, eumelanin is the dense, dark pigment, and it's the more protective
• 8:01
  of the two, and that absorbs and safely dissipates more UV than pheomelanin.
• 8:08
  Jamie: So eumelanin is the form of melanin that gives you the bronze tone and does
• 8:12
  actually contribute some protection, the one I'm evidently running in my body.
• 8:16
  Chris: That's it, and the kinda red-yellow corner is pheomelanin, and
• 8:19
  that's the one I'm more loaded with.
• 8:21
  But there's a, a thing here to take into account that not only is pheomelanin much
• 8:26
  less effective at dealing with UV light, um, but when sunlight hits pheomelanin,
• 8:31
  it can actually trigger oxidative stress, contribute to further damage.
• 8:36
  Jen: Which is, it's almost unfair, isn't it?
• 8:39
  I know.
• 8:39
  So for some people, the pigment isn't even neutral, it just works
• 8:43
  against them even without much sun.
• 8:45
  Jamie: So Chris's skin isn't just failing him, it's quietly
• 8:48
  making things a bit worse.
• 8:50
  No wonder you go off like a warning light
• 8:52
  Chris: Yes, thanks, Jamie.
• 8:53
  The man who stands near a window and tans anyway.
• 8:55
  You know, we're all delighted for you.
• 8:57
  Jen: Love it.
• 8:58
  So Chris, what actually determines the type and the
• 9:02
  amount of melanin in your skin?
• 9:04
  Chris: Yeah, so this is largely down to your genes.
• 9:06
  So certain genes influence whether your pigment cells produce more
• 9:09
  eumelanin or more pheomelanin.
• 9:12
  So people with more pheomelanin have, uh, fair skin, freckles.
• 9:16
  They're often red or blonde-haired, and are much more likely to burn than tan.
• 9:22
  Jamie: So somewhere in Chris's genetics, there's a switch firmly in
• 9:25
  the pheomelanin on position, but the eumelanin switch is pretty much off.
• 9:30
  Chris: Yeah, that's pretty accurate, Jamie, and it's the ultimate
• 9:32
  answer here, uh, to the question of why you tan and why I don't.
• 9:36
  So when sun hits, your skin can crank out the darker eumelanin pigment.
• 9:40
  You go that kinda nice bronze color and have a bit of protection, whereas
• 9:44
  mine is predominantly pheomelanin, so I won't go particularly brown,
• 9:47
  but I most definitely will burn.
• 9:50
  Jamie: So it was never that I tan harder than you.
• 9:53
  Your skin's just got nothing to tan with.
• 9:55
  Jen: Yeah, that's the heart of it, and the extreme version is the classic redhead.
• 10:00
  So around 1 in 20 make almost entirely pheomelanin, the reddish
• 10:06
  pigment, and barely any of the protective eumelanin, so they burn
• 10:10
  and freckle however careful they are.
• 10:12
  So it's not willpower failing, it's just the melanin that they were handed.
• 10:17
  Chris: That's it.
• 10:18
  I mean, I always used to joke that I've got so many freckles and they, I get
• 10:21
  millions more when I go in the sun.
• 10:22
  The only way I'd actually ever get a tan is if they all join up-
• 10:24
  Yeah … I've got one big freckle.
• 10:26
  Yeah.
• 10:26
  Um, but dermatologists often describe skin using what's
• 10:30
  known as the Fitzpatrick scale.
• 10:32
  So this grades your skin from one to six based on how readily it burns and
• 10:36
  tans- Mm … in response to sunlight.
• 10:38
  So, um, a Fitzpatrick type one is very fair skin, uh, that almost always burns
• 10:44
  and rarely tans, while type six at the other end of the scale is deeply
• 10:48
  pigmented skin that rarely burns.
• 10:50
  Mm. And this Fitzpatrick scale was, um, originally developed in the '70s
• 10:55
  to help doctors choose safe doses for certain light-based treatments.
• 10:59
  Jamie: So where do the three of us land on this scale?
• 11:01
  Chris: Yeah, so on the Fitzpatrick scale, I'm a one, probably
• 11:04
  unsurprisingly, maybe borderline two.
• 11:06
  There are some people a, a little bit paler than me, believe it or not.
• 11:10
  Um, so I've got … There's very little of the dark eumelanin pigment,
• 11:14
  so I've got no real tanning ability, almost no built-in protection.
• 11:18
  So my bare skin is about an SPF of two maximum, so pointless.
• 11:24
  Jen: Oh, it's not that bad, Chris.
• 11:27
  I'm a, I'm probably a two, so I'm not quite as fair-skinned as Chris.
• 11:32
  And Jamie, I'd put you somewhere around about a three or maybe a four with more
• 11:37
  eumelanin and the greater ability to tan and more natural protection from the UV.
• 11:42
  Um, and I think in very dark skin around, they're around a Fitzpatrick type six,
• 11:49
  I think researchers have estimated the natural protection may be roughly
• 11:53
  equivalent to an SPF of around 10 to 13, but that's only, like, a rough comparison.
• 12:00
  Jamie: Which still isn't much compared to a bottle of factor 50.
• 12:02
  Jen: Mm.
• 12:03
  Chris: It's so true, and that's why some people get caught out by this because
• 12:06
  people can assume that they've got darker skin tones, that they're protected.
• 12:10
  But as I say, SPF 13 at a max, it's not a lot, is it?
• 12:13
  Jamie: No.
• 12:14
  Chris: Uh, so even the best built-in protection sits way below the lowest
• 12:18
  sun protection factor that we would ever recommend, which is, I'd say 15, but
• 12:21
  it's probably more likely 25 these days.
• 12:23
  Mm. So no skin type, wherever you sit on the Fitzpatrick scale, does the job alone.
• 12:29
  Jen: And it's important to point out, isn't it, that every one of
• 12:32
  those skin types can still burn, and every one can be damaged.
• 12:35
  So the old version of the scale claimed that the darker skin never burns or
• 12:42
  gets damaged, which simply isn't true.
• 12:44
  Chris: It's not, and that myth does real harm, doesn't it?
• 12:47
  Mm. Because people with darker skin are often led to believe
• 12:49
  they, they don't need to worry.
• 12:51
  Um, but it's really serious, so skin cancers can end up getting spotted later.
• 12:55
  Yeah.
• 12:56
  Um, so the added protection is real, but in the scheme of things, the uplift versus
• 13:01
  paler skin types is not that big a deal.
• 13:03
  Jamie: So I never burn quietly turns into I never check, and that's the
• 13:07
  bit that actually carries a risk.
• 13:09
  Jen: Yeah, it is, and it works the other way, too.
• 13:12
  So I'm pretty sure even Jamie would burn if you overdo it, um, but you
• 13:17
  just get less of a warning sign.
• 13:19
  Jamie: Yes, that's true.
• 13:20
  I definitely do.
• 13:21
  So given some of us, namely no Chrises, are preset to burn, what actually works?
• 13:26
  Because never go outside is rather a boring, um, way to live your life.
• 13:30
  Jen: Yeah.
• 13:31
  Chris: Yeah, and I am unashamedly Captain Sensible when it
• 13:34
  comes to safety in the sun.
• 13:35
  I know you call me that anyway, but this is definitely a pet topic for me.
• 13:38
  Jen: You are
• 13:38
  owning it today.
• 13:39
  Chris: Absolutely.
• 13:40
  I, yeah, I do… I genuinely feel very passionately about this- Mm … um, 'cause
• 13:43
  I've done a lot of work in this area, and sadly I've seen the, the impact of
• 13:46
  sun damage, and it's, it's catastrophic.
• 13:49
  Um, so back to your question, Jamie.
• 13:50
  The first point to reinforce is that the tan itself isn't doing the protecting.
• 13:55
  So if you are spending time in the sun, you need something that
• 13:58
  genuinely is doing that protecting.
• 13:59
  So I'd recommend a, a good broad spectrum sunscreen, meaning it
• 14:03
  protects against both UVA and UVB, at an SPF I would say of at least 25.
• 14:08
  Some people say 15, but I'd go for 25 minimum.
• 14:12
  And really importantly is reapply it during the day.
• 14:15
  So if you're on holiday and you've been swimming, you must reapply.
• 14:18
  It's gonna come off.
• 14:19
  Even if it says it's water-resistant- Mm … they're not really.
• 14:21
  They're not that good.
• 14:22
  And if you're sweating a lot, I dunno about you, I always tend to burn on
• 14:26
  the forehead- Yeah … 'cause you- I just sweat it off the- Yeah, yeah
• 14:28
  the kind of receding hairline I've got.
• 14:30
  Um-
• 14:30
  Jen: Yeah, plus that you can do, like, the obvious things, can't you?
• 14:33
  Like wearing extra clothing, um, sitting in the shade, which do even more.
• 14:39
  And consider the timing when you're sitting out because the midday sun,
• 14:43
  that is strong stuff, isn't it?
• 14:45
  And, you know, it's safe to say, isn't it, that, um, the best version of all of these
• 14:51
  tips are the ones you'll actually do.
• 14:53
  There's no point in buying a fancy sunscreen that you
• 14:56
  leave in the bathroom drawer-
• 14:58
  Chris: Absolutely
• 14:58
  … Jen: and don't use because- Yeah … obviously that protects nobody.
• 15:01
  Jamie: Now, I mentioned them before, but I'd like us to talk about sunbeds.
• 15:03
  Jen: Mm-hmm.
• 15:05
  Chris: Yeah, and this is another thing, I'm getting on my soapbox today, but I'm,
• 15:08
  I'm gonna be unashamedly blunt about.
• 15:10
  Contrary to what some people believe, sunbeds are not a gentler option.
• 15:14
  They're very concentrated UV, and the real danger is the damage is mostly invisible.
• 15:19
  You don't get that kind of sunburn, uh, trigger to show
• 15:22
  you that something's happening.
• 15:24
  The harm is happening underneath.
• 15:25
  Jen: Mm.
• 15:26
  Chris: Um, and so many young people u- are using sunbeds too now.
• 15:29
  W- it's back in fashion worryingly.
• 15:32
  But actually starting young sharply raises the risk of
• 15:35
  serious skin cancer as you age.
• 15:37
  Mm. So in my personal opinion, sunbeds should be banned.
• 15:40
  Jen: Mm.
• 15:40
  Jamie: So when it comes to sunbeds, that single sheet of newspaper in the rainstorm
• 15:43
  we referred to earlier is now actually a sheet of newspaper soaked in petrol.
• 15:47
  Yeah.
• 15:47
  Good to know.
• 15:48
  Jen: Yeah.
• 15:49
  And there's another myth that some of, you know, some people might have
• 15:53
  heard, which is, you know, someone pale moves somewhere, like sunny, like Spain
• 15:58
  or Australia, and a few years later they look, like, permanently tanned.
• 16:03
  Surely that proves you can build up a tan over time.
• 16:07
  Chris: Well, you think so, and it is the most convincing one, isn't it?
• 16:09
  Mm. But it is a myth.
• 16:10
  It's actually almost back to what I was saying about getting
• 16:11
  one freckle and it joining up-
• 16:14
  Jen: Yeah
• 16:14
  … Chris: to produce the tan.
• 16:15
  Because if those people are a, a type I or a II on the Fitzpatrick scale, they
• 16:21
  haven't built a tan or trained their skin to somehow tan because they can't.
• 16:25
  Y- the, our biol- biology doesn't allow it.
• 16:27
  So what you're actually seeing on those people who are lucky enough to
• 16:30
  go and emigrate to the sun- … is years of accumulated UV injury.
• 16:34
  So the skin is going darker in, in more and more patches and patchy places.
• 16:38
  Jen: Mm.
• 16:38
  Jamie: And I suppose those patches don't come alone.
• 16:41
  Chris: No.
• 16:41
  Jen: No.
• 16:42
  They come with rough, leathery skin, wrinkles, age spots,
• 16:48
  a patchy, uneven color.
• 16:50
  It isn't that your skin is learning to cope, it's the skin being worn down,
• 16:54
  and unlike a real tan, it doesn't fade.
• 16:58
  Chris: That's right.
• 16:58
  I mean, you've, you've basically worn down its resilience to the sun.
• 17:02
  Yeah.
• 17:02
  Um, and it's, it's effectively a record of damage.
• 17:04
  It's not a healthy bronze.
• 17:06
  And the thing is, it carries a real risk of skin cancer down the line.
• 17:10
  Jen: Mm.
• 17:10
  Jamie: So you generally genuinely can't train your skin into it.
• 17:14
  It's the one thing where trying harder actively makes things worse.
• 17:18
  Jen: Yeah.
• 17:19
  And before anyone swears off daylight forever, a bit of scor-
• 17:24
  a bit of sun isn't the enemy.
• 17:25
  So your skin uses UV to make vitamin D. You can, you know, you
• 17:30
  can get that, um, more safely from food or a supplement though, than
• 17:34
  actually baking yourself in the sun.
• 17:36
  Chris: Yeah.
• 17:37
  And, and it's so important 'cause w- we're not anti-sun, are we?
• 17:39
  Yeah At all.
• 17:39
  So yeah, there, there are loads of health benefits to the sun.
• 17:42
  Mm. It's all about safety.
• 17:44
  Mm-hmm.
• 17:44
  That, that's what we're talking about here.
• 17:46
  And, um, when it comes to vitamin D, it's something that we covered in the,
• 17:50
  the vitamin D episode of the podcast, and it's really important for people to
• 17:54
  understand this, that you only need a little bit of UV exposure to stimulate
• 17:58
  vitamin D production in the skin.
• 17:59
  Mm. So the final myth I'm gonna bust here is- The concept that applying
• 18:03
  a, like a really high SPF sun product will inhibit the skin's ability to
• 18:09
  produce vitamin D, that's not the case.
• 18:12
  Mm. You only need a very small amount of UV exposure to produce that vitamin D.
• 18:17
  Um, but as you say, Jen, you know, you can get vitamin D from foods or supplements
• 18:21
  too, meaning you can do it safely without kind of risking overexposure to the sun
• 18:26
  in that quest for good vitamin D levels.
• 18:30
  Jen: Okay, so pulling it all together, we've got the same number of cells,
• 18:34
  but the pigment they're set to make, the eumelanin or pheomelanin, is mostly
• 18:39
  fixed by your genes before you were born.
• 18:42
  Jamie: And the tan itself was never the healthy bit.
• 18:44
  It's just the skin reacting to damage that has already been done.
• 18:48
  Jen: So here's the clean answer to where we started.
• 18:51
  Why do some people tan while others don't?
• 18:54
  Because tanning ability is genetic, set by how much of the dark
• 18:59
  protective pigment your skin can make.
• 19:02
  Um, plenty of it and you tan, very little and the same sun just burns you instead.
• 19:08
  There's no such thing as a safe tan, and you sadly can't train
• 19:13
  your skin into making one either.
• 19:16
  So that's it for this week.
• 19:17
  Make sure you hit that subscribe button.
• 19:20
  We're unpacking the science behind everyday questions each week.
• 19:24
  Tell us in the comments what you'd like us to explore next.
• 19:28
  Thanks for geeking out with us.
• 19:30
  But for now, that's it from me.
• 19:31
  Jamie: That's it
• 19:32
  Chris: from me.
• 19:33
  Jamie: That's it from me.
• 19:34
  Jen: Bye for now