Recently I made a video about what the world looks like in the ultraviolet
Some things look the same but generally it's hazier
sometimes light and dark are flipped
skin looks blotchier and fake teeth stand out
Whoa!
Smile for me
Oh my goodness
Are my teeth black?
Do you have a fake tooth baby?
--Yes --Which one?
but the idea for this video started a long time ago with a question I had which is,
How does non ionizing radiation like ultraviolet light
like ultraviolet light damage skin and lead to cancer?
I do like to tell people that if you want to see how good your skin could look,
look at your butt
because that's an area that doesn't get sun
and even old people have perfect butts
it's how your skin would age without the sun
when I thought about what UV light must be doing to our cells and our DNA,
I imagined it would be getting in there and breaking all these bonds and that would be the problem
but in fact it's kinda the opposite
UV actually facilitates the formation of covalent bonds in our DNA that shouldn't be there.
It comes in and it kind of creates these unauthorized bonds between the bases
called pyrimidine dimers
instead of having them bonded across it bonds the one next to each other
if that makes sense. -- Oh. -- Yeah.
so what happens is two thymines, which are side be side,
can actually get covalently bonded together
and that creates a lesion on the DNA you can think of it like a little bump
that makes the DNA hard to read and work with
That's not enough in itself to cause skin cancer. If that were the case we would just be covered in skin cancers
then the next step is that we have to repair it
and in the repair,
that's when you form mutations that could eventually lead to cancer through a bunch of different pathways
and there's actually people who have specific
genetic issues that they can't repair these issues and they are covered in skin cancer
UV has other effects on the body like
suppresses the immune system so, as Haley says, it's a "double whammy"
There's also kind of a double whammy because UV not only induces these unauthorized bonds
it actually tamps down our natural immune system
so one of the best ways we fight cancer is through our immune system
we have constantly need surveillance through our skin
so not only is sunlight creating these problems,
It's actually reducing our ability to fix them.
So unfair
UV light also causes us to visibly age. It's called photo-aging
I should clear up a misconception here that I had which was, I thought glass blocks all ultra-violet light.
so I thought if you're inside a car, for example, you really don't need to put on sunscreen because,
you're not being exposed to UV light
The car does not block UVA. It's glass
It does block most UVB
but you're still susceptible to those sunspots and those wrinkles through the glass
and a lot of my patients if you look and you compare their hands,
the left is is more wrinkled or has more sunspots on it because they're driving.
So they're sticking that hand... --Sticking that hand out their truckers. Absolutely you can see it the worst
And there's a really famous picture of someone whose left side of their face
is significantly more, as we'll call photo-aged, or old-looking, than the other side of their face.
So that's mostly UVA and UVA, as I said, it's a longer wavelength, penetrates a little bit deeper.
so wrinkles mostly come from destruction of our collagen and elastin
which is natural fibers that hold up the scaffolding of our skin
so with age the cells that secrete collagen
they're called fibroblasts they stop producing as much
and what the Sun does is it breaks down the existing collagen and elastin we have
so fibroblasts really like to be stretched, they like to be pulled and collagen does that, that collagen matrix
so the Sun damages the collagen fibers leading to less stretch on fibroblasts
and less production of collagen
which means that you look a little more saggy
I know it's very depressing so sun protection helps the degradation of those collagen and elastin fibers
You know there are a lot of creams on the market that claim to be anti-aging
but the one that really works
is sunscreen
preventing ultraviolet light from hitting your skin is the best thing you can do
to avoid skin cancer and to avoid photo aging
So yeah. It's good advice. Use sunscreen.
hey I'm on set for Jurassic world fallen
Kingdom and I'm here filming sci-fi test
lab where we try to recreate some
dinosaur parts out of machinery and test
them out so if you want to see that then
click here