To some extent, almost everyone on Earth is aware of the harmful effects of the sun in
ageing skin.
Skin ageing is divided into four main categories:
* Wrinkles or a change in texture * Lack of firmness and skin sagging (ptosis)
* Vascular Disorders * And Irregular Pigmentation
Over time, sun overexposure can single-handedly contribute to all 4 of these cosmetic flaws.
Now, that’s not to say that sun exposure isn’t good for you.
There’s a sea of studies that link moderate sun exposure with improved mental health,
serotonin release and better attention spans.
In fact, in An and colleagues 2016 paper on sun exposure in the workplace, they found
a significant increase in job satisfaction and decrease in anxiety when their seating
was exposed to some form of direct sunlight as they worked their hours but that’s not
what we’re here to discuss.
The issue isn’t visible sunlight but rather the harmful UV-A and B rays that sneak their
way through our Earth’s ozone layer.
Before we talk about wrinkles, here’s a quick breakdown of how Ultraviolet radiation
reacts with our skin.
95% of the ultraviolet rays that reach Earth are UV-A. For a while, scientists have thought
that UV-A rays were not harmful because they didn’t technically cause skin cancer, but
that’s like saying guns aren’t harmful because they didn’t technically kill anyone.
Nowadays we’re more aware that UV-A is immunosuppressive and can penetrate deeper into the skin than
UV-B to create intermediate compounds such as oxygen radicals which themselves are very
reactive and disrupts DNA, thus, indirect DNA damage.
UV-B is the higher energy cousin of UV-A which goes directly to the DNA and messes up replication
leading to mutations.
Most importantly, both types of rays damage collagen fibers responsible for skin elasticity
and reduces Vitamin A for skin regeneration.
Just look at what sun damage does to UV-protected plastics.
Do you really think your skin will fare better?
Scientists have been trying to quantify photoinduced skin ageing (sun damage) for years now.
How much damage does x amount of exposure per day cause?
One way of quantifying skin damage is with the Glogau scale, developed by Dr Richard
Glogau.
With the skin ageing quite linearly for most people, certain regions are more prone to
wrinkles than others.
For instance, natural indentations that help facial muscles move freely, deepen with collagen
loss first.
Then regions that don’t see as much movement or stress start to wrinkle as fat compartments
sag, dentofacial bone remodels itself and skin becomes lax.
In Flament Et al’s 2013 paper, they use their own method of grading sun damage from
0 to 8.
For the study, they recruited 298 Caucasian women and had a dermatologist rate each face’s
sun damage status to give it a heliodermal score with its correlation to age, i.e. how
likely a face of a certain age would be to have this particular cosmetic flaw.
As one would expect, older faces have greater instances of sun damage on average as it accumulates
over the years.
Here’s the interesting significant part though.
Patients who classified themselves as sun-phobic vs those who are sun-seeking had considerably
fewer wrinkles and skin discolourations.
Also, the sun-seeking group appeared on average 3 years older than their actual age with an
outlier at >70, because no one seems to be able to guess ages correctly after that magical
point.
It’s worth noting that both sun-seeking and sun-phobic groups showed similar levels
of skin sag, which is predominantly determined by gravity, fat compartments, musculature
and the underlying ligaments, rather than the sun’s rays, so this study does appear
quite valid.
Although this study was conducted on fair-skinned participants, it doesn’t imply that darker-skinned
people get a free ticket to frolic in the sun.
In 2001 Chung Et al took a look at the ageing Korean population and 19.2% of Koreans with
daily solar exposure of 1-2 hours had wrinkles vs 64.6% of those with more than 5h/day.
This trend was similar for both genders but women had a greater chance of developing wrinkles
than men with a sharp spike after 50 years of age.
Melanin is a naturally occurring UV-absorbing agent that blocks direct ultraviolet light
from reaching the DNA of epidermal cells.
I previously explained how UV-A rays indirectly cause cancer by creating oxygen radicals,
but fortunately, melanin can neutralize these harmful free radicals by scavenging them before
they can damage DNA.
Being darker skinned is a huge evolutionary advantage for people living in areas with
high sun exposure and it’s no surprise that anthropologically, indigenous skin colour
is correlated with distance from the equator.
Unsurprisingly, there is also a correlation between lighter-skinned populations and higher
prevalence of skin cancer, with the major outlier being Australia attributed to the
huge ozone hole in the atmosphere above it.
Also, sunlight can encourage the production of freckles which many find unique.
Freckles themselves are concentrated clusters of melanized cells and although some people
are genetically predisposed to have them more than others, they only erupt when the skin
has been exposed to enough UV rays.
They shouldn’t be confused with sunspots or liver spots which resemble freckles but
form only after years of accumulated exposure to the sun.
Also, they’re larger, more sparse and an indicator of age, much like wrinkles, whereas
freckles are seen in the young and old alike.
Freckles can form in people of all skin colours but are obviously more noticeable in people
of lighter tones with commercial editors going so far as to change the contrast to make them
stand out more.
There’s very little research on how people perceive freckles aesthetically, but modelling
seems to fetishize it as a unique skin feature to the likes of vitiligo, albinism or alopecia
so take that as you will.
If you’ve ever wondered why black celebrities such as , Pharrel Williams and Will Smith
look well below their age, their melanin-rich skin is part of the reason why.
Having higher melanin, or specifically eumelanin in darker skin better protects the skin from
harmful UV rays and thus photoinduced ageing.
Up to a point, darker skin can basically act as a permanent sunscreen.
Infact, Kaidbey’s study showed that darker skin tone had a UV-B protection factor of
13.4 vs white skin’s 3.4 which is almost 4 times larger.
One downside, however, is that black skin is more prone to discolouration, dark spots
and hyperpigmentation with the more adverse potential of keloid scarring.
Interestingly enough, mixed-race skin seems to fare somewhat better in comparison to caucasian
skin tones which were rated as the worst for ageing.
Black, asian and caucasian skins react to the sun in very different ways.
For starters, black and asian skins don’t even produce the same type of melanin with
black skin producing eumelanin and asians producing pheomelanin giving them subtly different
skin tones.
In a 1990 study by Goh on Singaporean Chinese, Indonesians and Malaysians, the most common
sign of sun-damage was skin hyperpigmentation where the skin takes on an uneven tone and
sunspots begin to appear.
Singaporean participants developed wrinkles more gradually and even then they were quite
fine and unnoticeable.
White skin on the other hand had both more noticeable dyspigmentation and severe wrinkles.
We’ve already spoken about how excess sun exposure ages white skin in a previous study,
but to drive the point home, a separate study from Arizona USA found women getting more
than 12 hours per week of sun exposure appeared 5 years older on average by objective ratings
than those with less than 2 hours per week of sun exposure.
Darker skinned people, on the other hand, had a significantly lower incidence of all
the adverse effects seen in their fairer skinned counterparts..
Although darker-skinned people have an overall delayed onset of wrinkles, they can also eventually
develop wrinkles in the same manner as any other skin type.
The most common features of sun damage in black skin were fine wrinkles, changes in
skin texture and hyperpigmentation which in excess can create an uneven, darkened skin
tone.
Black skin loses relatively less dermal volume with age minimizing skin sagging.
A good example of this is nasolabial folds that form with fat ptosis.
We’re working with practising medical doctors to do a full write up on over at the QOVES
site with a focus on aesthetics.
We’re also working on a tool that can diagnose facial flaws for clinicians and you alike
to use, but I don’t want to give away too much just yet, follow us on Instagram and
Twitter to stay up to date.
So to summarize, this absolute barrage of information, you shouldn't be actively avoiding
the sun as that’ll only harm your mood in the short term, but if you look like Robert
Pattinson in Twilight Breaking Dawn, it’s best to keep in mind just how much unprotected
sun exposure you’ve gotten for the day.
Even the best of sunscreens don’t work perfectly, either by you misapplying it, it rubbing off
without you noticing, or it simply not being strong enough as is the case in certain parts
of the world.
How well your skin will age does depend on its pigmentation, with black being the best
and white caucasian tones being the worst.
Asian, black and Caucasian races have different types of melanin that react to the sun in
different ways resulting in variable types and severities of skin lesions forming overtime.