How does the Sun damage your skin?
You might have heard by now the importance of sun protection for your skin in the prevention of sun damage and skin cancers. Despite this, many of us do not always make sun protection a priority. As someone born and raised in the Mediterranean, I am accustomed to sunny weather. I do not burn easily and am not aware of the Sun’s immediate effects. It is therefore not natural behaviour for me to be pedantic about sun protection. After all, can it really be that damaging?
An ounce of prevention is worth a pound of cure
Oftentimes in the face of a skin issue like sun damage, we want to be told the solution lies in latest and greatest innovation in skincare formulations. Or the newest technological advances in laser therapy, the strongest acid peels. Not that we should be wearing sunscreen. We want to be in on this big high-tech secret that solves all our problems and even raises our children in the process. The idea that one magic pill or potion could erase years of misbehaviour is just more appealing. The truth is years of sun damage can easily be averted, provided we take some small steps of prevention. But we must first understand how it occurs so we can identify how to prevent it.
The lowdown
So, we are aware of sun damage. But what exactly are the implications of prolonged sun exposure and why does sun damage even happen? We often wait until we see the visible signs of an issue to take action. However, the small steps we take each day will make the greatest impact. And this applies to our skin and preventing sun damage. Instead of waiting for the visible signs of sun damage to surface, we should be actively working to mitigate the effects.
If you’re a science nerd like me, sometimes it is only the factual information that is able to persuade me to act on something. Simply being told that I should do something without being given the facts is not enough. Partly because I don’t like being told what to do – period. And partly because I don’t ever trust only one source of information. I like to look at the mechanisms behind a problem and conduct my own investigations from multiple sources. So, here is the stripped back essence of what UV radiation does to skin.
UV radiation
Ultraviolet (UV) is part of the electromagnetic spectrum of radiation falling between visible light and X-rays. The sun emits this UV radiation, but unlike light rays or infrared, it cannot be seen or felt. UV radiation has been classed as a Group 1 carcinogen, meaning it has strong cancer-causing potential.
There are a few different types of UV radiation: UVA, UVB and UVC. UV radiation is classified as a carcinogen due its tumour promoting and tumour initiating effect. When we are exposed to the sun, UV radiation contributes to the depletion of stem cells, causes stem cell DNA damage and eventually leads to photoinduced ageing of skin.
Saving the ozone layer will not only save the environment, but it will save our skin too!
The ozone layer acts as a protective barrier to absorb a lot of UV radiation from the sun. UVC is completely filtered out by the ozone layer but UVA and UVB are still able to reach the earth’s surface. The continual depletion of ozone, as a result of certain compounds and pollutants being released into the atmosphere, poses a risk in aggravating the health effects caused by these harmful rays.
In this post, I am going to focus on ultraviolet A and ultraviolet B as they relate to sun damage of the skin and aging.
The difference between UVA and UVB
What are UVA rays?
UVA rays account for most of the sunlight reaching the earth and penetrate more deeply than UVB. This means that they can penetrate into the deeper layers of the skin at the dermis. These rays are responsible for the adaptive melanisation (or tanning) of our skin. Melanocyte cells respond to UVA rays by triggering melanin to darken the skin in an attempt to protect it. The darkening of the skin from a tan is in fact the skin’s response to the damage of DNA.
Silent killer
You do not physically feel the effects of the damage on your skin in the sense that unlike sunburn, solely tanning is not unpleasant and does not cause discomfort. However, this is bad news for those of us who thought that if we simply tan and are not prone to sunburn, we are at less risk than those who burn. Just because our body does not show the immediate adverse effects of the sun does not mean sun damage is not occurring.
Repetitive UVA exposure ages skin cells, damages DNA, precipitates the formation of wrinkles and is responsible for the majority of skin cancers. As long as the sun is out, UVA rays are present. They penetrate glass so that even when you are indoors, if you are in a building with windows, you are being exposed to UVA rays.
What are UVB rays?
UVB rays are slightly higher in energy than UVA rays. They are especially prevalent at high altitudes and on reflective surfaces (explaining that bad sunburn you got on your ski holiday) but do not penetrate glass significantly in the way UVA rays do. UVB is chiefly responsible for the reddening of skin and erythema (sunburn) and plays a role in skin cancer. Its inflammatory effect kills keratinocytes and voila, you have sunburn.
This type of UV radiation affects the more superficial epidermal layers of skin but also contribute to tanning and photo-ageing. It induces skin pigmentation by increasing melanin synthesis. The oxidative stress induced by UV exposure increases the production of reactive oxygen species, leading to the proliferation of epidermal keratinocytes. These accumulate and increase epidermal thickness so that the surface layer is dull, dense and crepey.
B is for burn
UVB is more efficient in inducing immediate erythema (or sunburn) but does trigger melanin synthesis and will eventually lead to delayed tanning. The overproduction of melanin skin cells can form clusters of darker skin. Cue hyper pigmentation, dark spots and dullness. With age, the outer layer of skin becomes dense, dry and dull. Think that leathery skin texture with dark patches that you see on people who lay on the beach without protection for years.
Vitamin D
UVB however, also plays a vital role in generating vitamin D, which is a steroid hormone that regulates over 1000 biochemical processes in the body. It is important to keep vitamin D levels in check while also being smart about sun protection. It is a myth that tanning booths are a good source of vitamin D since UVA rays are the type mainly used in tanning, and not UVB (so don’t buy into the lie that indoor tanning booths are a good source of vitamin D, folks).
Keeping your skin protected from the Sun
Some simple steps you can take to keep your skin protected from the sun:
- Liberally apply a broad-spectrum sunscreen to the exposed areas of your skin
- Reapply sunscreen after swimming or sweating as it can wash off
- Wear sunglasses to shield your eye area
- Stay in the shade during peak hours of sun
- Wear hats to protect your scalp and face
- Avoid skincare ingredients that may induce photosensitivity
- Do not allow your skin to burn
- Avoid tanning booths and use self-tanners instead. Or go au naturale.
Certain ingredients make you more sun sensitive
There are a number of skincare ingredients that can increase the skin’s sensitivity to the Sun. Such ingredients include various fragrant plant oils, glycolic or lactic acids, and benzoyl peroxide. This means that, if your skincare routine contains any of these ingredients, there is even greater reason to use an SPF daily.
Various ingredients also help to lessen the effects of excess sun exposure. I wrote an entire article about vitamin C skincare benefits – spoiler, it also helps with photo-protection. Ingredients such as hyaluronic acid
What does SPF do?
The SPF rating on sunscreens refers to the protection from UVB rays. It essentially lets you know how long you can stay in direct contact with the sun before your skin begins to burn. For instance, if your skin begins to burn after 20 minutes in the sun, applying an SPF 30 means it will take 30 times longer before you burn.
Because of the lack of liberal sunscreen application, it is best to apply an SPF 30 or greater so that you can be sure you are getting adequate sun protection. An SPF beyond 50 can be misleading. It is probably more beneficial to frequently reapply an SPF 30, than to assume an SPF 100 will protect you 100 times more effectively. Many countries ban a rating over SPF 50 due to the false sense of security it gives.
In terms of percentage of UVB radiation that SPF will block out, SPF 15 sunscreens will filter about 93% of UVB rays, SPF 30 sunscreens filter out about 97%, SPF 50 sunscreens about 98%, and SPF 100 about 99%. As the SPF rating increases, the difference between consecutive ratings becomes smaller. It should be noted that no sunscreen will block out 100% of all UV rays.
What to look for in a sunscreen
Because SPF relates only to protection from UVB, opt for a “broad spectrum” sunscreen. This means it will shield you from both the UVA and UVB rays and will safeguard you from the visible surface level effects of sun damage as well as the deeper level damage to skin.
In an upcoming article, I will be giving a complete overview of all the very best SPF products with the best textures, best ingredients and best under makeup. As a teaser, I will mention this Murad SPF 50 is a game changer. And this non toxic sunscreen is the best “natural” option I have tried yet. You will also want to check out this mineral sunscreen review as a great option for under makeup wear. 
Stay vigilant
At times it might feel a little wasteful or redundant to slap on sunscreen just to pop outside for five minutes, or during a cloudy day. I must admit I am still having to acclimate to the practice of daily sunscreen use. Keep in mind that although you cannot feel or see the UV rays, they are still present at all times – apart from at night when the sun is no longer in the sky. As long as you can see outside, sun damage is able to occur, and the damage is cumulative.
It is never too late to begin to take adequate protection of your skin and prevent further harm. The fact is, this isn’t even an aesthetic matter. Being mindful of UV exposure is simply ensuring that you are taking care of your health. Your skin is your largest organ; it’s a living organism. Take care of it and it will take care of you.
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Wishing you boundless love, endless light, and life without limit,
Shannon xo
This post is not sponsored. All opinions belong to the author.
Sources:
Panich, U., Sittithumcharee, G., Rathviboon, N. and Jirawatnotai, S. (2016). Ultraviolet Radiation-Induced Skin Aging: The Role of DNA Damage and Oxidative Stress in Epidermal Stem Cell Damage Mediated Skin Aging. Stem Cells International, 2016, pp.1-14.
D’Orazio, J., Jarrett, S., Amaro-Ortiz, A. and Scott, T. (2013). UV Radiation and the Skin. International Journal of Molecular Sciences, 14(6), pp.12222-12248.
Fda.gov. (2018). Ultraviolet (UV) Radiation. [online] Available at: https://www.fda.gov/radiation-emittingproducts/radiationemittingproductsandprocedures/tanning/ucm116425.htm
