I forgot to use sunscreen before I left the house but I’m already outside.
I’ve got sunscreen in my car but I won’t be able to wait for 20 minutes for the sunscreen
to dry.
Is there any point in using sunscreen at all?
Hmm what do you think Pingu?
Hey guys welcome to DocUnlock where we help you learn more about your body so that you
can make better decisions about your health.
Today Pingu and I are going to help you learn about sunscreens.
We’re going to answer some common questions and also bust some myths as we go.
Let’s get cracking!
First question, I don’t need to use sunscreen all the time.
So this one’s true.
When the UV index is more than 3, that’s when it’s recommended to use sunscreen.
Second question, sunscreens shouldn’t be used for babies.
So this one is true.
Kids less than six months of age tend to have very immature skin so when you put sunscreen
on them, there is a possibility that the ingredients in sunscreens can irritate their skin.
So to protect young babies from sun damage, the best way is to hang out in the shade or
use UV protective clothing.
Next question, sunscreen doesn’t work unless you’ve waited for twenty minutes.
So this is an awesome question and something that I’ve actually thought about.
In theory, technically, sunscreen is ready to go straight out of the bottle.
The ingredients don’t need to have anything done to them for them to protect you from
UV.
But the reason why manufacturers talk about this twenty minute rule, is because the sunscreen
works best when it’s applied evenly and there is a dry even film on your skin.
But that doesn’t mean that even if the sunscreen hasn’t had that time to dry, that it’s
providing no protection.
It’s just providing less effective protection.
So if you’re outside and you’ve forgotten your sunscreen, and you’ve got some in your
car.
Go ahead, use it.
Because any amount of sunscreen is going to be better protection than no sunscreen at
all.
Question number four, physical sunscreens don’t need to be re-applied.
Well this one’s clearly false but I can understand why people may ask this question.
Hi Pingu!
The reason why this question comes up is because there is this understanding that the ingredients
in chemical sunscreens do breakdown when they’re exposed to UV.
But it is thought that the physical sunscreens like zinc and titanium based sunscreens, well
those ingredients don’t break down.
But the issue is, is that, reapplying sunscreen has got nothing to do with the breakdown of
the actual ingredients.
It’s because sunscreen rubs off your skin or drips off in the sweat.
So it’s not because it’s actually breaking down that you need to reapply.
Regardless of the sunscreen ingredient, zinc, titanium, chemical sunscreen, you still need
to re-apply regularly to get the best effect.
Question number five, ingredients from chemical sunscreens are absorbed and cause hormone
problems.
Again this is such an awesome question because it has sort’ve a half half answer, half
true half false.
So first thing to get out of the way is that physical sunscreens, those with zinc and titanium,
don’t have any absorption into the body.
None at all.
It just sits on the skin and doesn’t pass through the epidermis.
But the ingredients in chemical sunscreens do have some absorption.
In fact I think there’s a study, which had 32 people, and they applied sunscreen for
a week.
The researchers took samples of urine and blood, and found there were detectable levels
of sunscreen.
But the thing is that absorption is not the same as having a biological effect.
So in that same study, when the researchers tested the hormone levels, they were exactly
the same as before, no change.
So just because there is some absorption of chemical sunscreens, doesn’t mean it’s
having any harm for the body.
There’s another study that’s often quoted on the internet which is a rat study.
So in this study, rats were actually fed astronomical doses of these sunscreen ingredients and they
found that the womb size, or the uterus size increased in these rats.
There was a subsequent paper which discussed this study, and actually calculated how much
sunscreen you would need to use to get that same level.
And they calculated that with regular sunscreen use, humans would need to apply sunscreen
for something like 277 years to get the same dose.
So again, not really relevant to what we’re talking about because we’re just not using
sunscreen in that kind of dose range.
But if you are worried about hormone effects from sunscreens, the simple solution is to
use physical sunscreens, the ones with zinc or titanium, because they don’t have any
absorption at all so nothing to worry about.
Next question, makeup protects you from the sun.
Well, Pingu and I don’t know much about makeup, because we’re ruggedly handsome
as it is.
Yes what happened girl…
But there is some truth to this.
Foundation makup especially can provide some sun protection but it’s usually anywhere
up to SPF four and five, which is not usually enough for most people.
There are some makeup products which include up to SPF fifteen sunscreen ingredients so
that might be a good choice.
Just remember that some of those cosmetics don’t have broad spectrum protection.
So if you can find a cosmetic makeup, like a foundation, which is broad spectrum, that’s
going to be better than UVB only protection.
Okay so question number seven, sunscreens can cause heat burns.
Well this one’s definitely a myth.
Well it’s true that sunscreens have these ingredients, which convert UV light into heat.
I mean the UV light that’s absorbed has to go somewhere.
But this is no where near as much heat as is required to get actual heat burns.
So, this one’s clearly false.
So Pingu is having had enough of recording, she wants cuddles, this is what her cuddle
position, we call her super Pingu, but we’re going to push on.
Pingu, the next question is I can’t use sunscreens because I am allergic to them.
So this can be true for some people.
People can react to the fragrance, sometimes the preservative, or even the sunscreen ingredient.
The rate of this is actually quite low.
So one study looked at about 24 thousand people, and found a one percent rate of allergic reactions
to sunscreens.
But if you have had a allergy to sunscreens, try using a physical sunscreen, with titanium
and zinc, that minimises preservatives and fragrances because these tend to be better
for sensitive skin.
Pingu the next one is, glass blocks UV so I don’t need to use sunscreen.
So this one’s a myth.
I showed you in my Vitamin D video how glass blocks UVB, but doesn’t block UVA.
So if you’ve got an office desk right next to the window, or you’re going for a long
car ride, then using a broad spectrum sunscreen to protect yourself from UVA, is definitely
worth your while.
Next question, and question number ten, using sunscreen causes Vitamin D deficiency.
This is a super interesting one.
So, in theory, when sunscreens are used exactly in perfect experimental conditions, they block
pretty much all UVB, and so in theory, that would lead to Vitamin D deficiency.
But here’s the kicker, when they did trials to compare Vitamin D levels in real world
use of sunscreens, they found that sunscreen actually had no effect on Vitamin D. And there
might be a few reasons for this.
The ones that come to mind is that, in real life, you don’t actually use as much sunscreen
as you need to, to completely block UV.
And also, you don’t tend to re-apply frequently enough.
So the fact that the skin is able to make Vitamin D very quickly, means that even with
sunscreens, there’s still going to be enough UV around for your skin to be able to make
enough Vitamin D. So definitely a myth, sunscreens don’t in themselves cause Vitamin D deficiency.
Okay and we have question eleven, using sunscreens doesn’t actually protect people from melanoma.
So I don’t know where this one came from, but it’s clearly false.
In fact there was a very important randomised trial that found that sunscreens protect from
invasive melanoma, by seventy three percent.
That’s huge.
So definitely use sunscreens to protect yourself from melanoma.
I will say that there are some forms of melanoma which are not related to UV, but that’s
very rare.
Ninety five percent of melanomas are related to sunburns and UV.
So that’s it guys this is the last episode in this series on skin cancer and sunscreens.
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videos.
Thanks for watching and I’ll see you in the next one.