A blog that gets nerdy for beauty

UV damage: The main culprit in early signs of aging


UV  damage happens when the electromagnetic waves from the sun comes in to contact with unprotected skin. Electromagnetic waves come at different wavelength, the visible light is what we see when the sun is shining. UV, the one that causes skin damage, is not visible to the human eye and is present even when its cloudy outside.

UV damage from the SUN

Source: http://www.eyesolarlux.com/light-technology/uv/

UV (ultra-violet) can be classified as UV-A, UV-B and UV-C.  UVB  causes burning and reddening of skin (sunburn) and targets the outermost layer of the skin. It contributes to skin darkening, when exposed to sun. UVA penetrates the skin more deeply than UVB and has been known to cause the signs of photoaging. UVB is significant between 10am to 4pm while UVA is present relatively at equal intensity at all daylight hours. So if you are concerned about skin darkening, avoid the sun from 10am to 4pm, which causes the most darkening effect. If you’re concerned about skin aging avoid the sun (or wear sunscreen) all day.


UVA and UVB rays are of the most concern, since it penetrates the atmosphere and plays a significant role in skin aging and skin cancers.


UV rays are proven human carcinogen by the U.S Department of Health and Human Services and the World Health Organization.

Ultra-violet (UV) rays are proven human carcinogen by the U.S Department of Health and Human Services and the World Health Organization. It causes non melanoma skin cancers (NMSC) by damaging the skin’s cellular DNA. Fair-skinned people are of the most concern of skin cancer. Dark skin is still at risk and should avoid excessive sun exposure


Exposure to cold and wind causes skin damage, but these are of little significance compared to UV damage from the sun. UV damage is responsible for most visible signs of aging: appearance of wrinkles and loss of skin’s elasticity. Elastin fibers naturally degenerate in aging skin. However, this is intensified by prolonged exposure to sun. The following are the other visible signs of sun damage:

  1. Uneven pigmentation
  2. Appearance of age spots
  3. Possible development of skin tumors
  4. Appearance of dilated blood vessels in the skin
Wrinkle Formation in UV damaged skin

Wrinkle Formation in UV damaged skin

The image below shows a very disturbing truth about the damage that can be caused by UV exposure.  according to The New England Journal of Medicine, truck driver Bill McElligott, 69, has unilateral photoaging. Ultraviolet A (UVA) rays transmitted through the window of his delivery truck (remember that UVA can penetrate through glass) have severely damaged the skin on the left side of his face during the 28 years he has spent driving.

UV damaged skin on  face

Bill McElligott, 69 with UV damaged skin on his face


To completely protect your skin from uv damage, you’d have to stay under the shade forever – which is impossible. For instances where sun exposure is unavoidable, apply sunscreen or sunblock.  There are many products in the market that promises “fountain of youth” but among all these, sun protection is the most basic anti-aging product since sun exposure contributes to most of the visible signs of aging.

Sun screen preparation can contain physical or chemical sunscreens or combination of both. Physical sunscreens (generally referred as SUNBLOCK) work by acting like a mirror and reflecting and dispersing sun’s rays upon reaching the skin’s surface. Titanium dioxide and zing oxide are the most common component of physical sunscreens. Chemical Sunscreens work by absorbing uv rays, thereby preventing them from penetrating the skin. Substances used as chemical sunscreens are oxybenzone, benzophenones, and paraaminobenzoic acid (PABA). Check the labels.

Chemical sunscreens or sunblock, which one is better? It really depends on your preference. Because (chemical) sunscreens are chemically reactive, it may cause irritation to some skin (luckily, i have no problems using them). Sunblocks are less likely to cause irritation but these products are usually not that pleasing to use. Because of their large particle size, they leave a white, eeeky weeeky film on the skin. For best sun protection and improved skin feel, most formulations combines physical and chemical sunscreens.



Sunscreens come in different SPF values.  Sun Protection Factor,is a measure of how well a sunscreen will protect skin from UVB rays, the kind of radiation that causes sunburn, damages skin, and can contribute to skin cancer. Take note however, that SPF scale is not linear:

  • SPF 15 blocks 93% of UVB rays
  • SPF 30 blocks 97% of UVB rays
  • SPF 50 blocks 98% of UVB rays

So, one way of looking at this is that SPF 50 sunscreen only gives you 1% more protection than SPF 30 sunscreen. This is further illustrated in the graph below.

UVB protection vs SPF

UVB protection vs SPF


UV rays are indeed, the main culprit for early signs of aging. To delay the appearance of wrinkles, age spots and prevent skin cancer, always protect your skin from the sun’s harmful UV rays. UV rays can penetrate clothing and even glass (in the case of UVA rays). Even when its not sunny,  UV rays can still penetrate our skin and cause UV damage. It is therefore important to keep this in mind: Wear sunscreen even when you’re at home. Wear sunscreen even when it’s raining. Wear sunscreen even when you’re at home….and it’s raining.

avoid long sun exposure

avoid long sun exposure

Article written by:

Anne Porter

Hi! I’m Anne. I am a chemical engineer from Cebu, Philippines. I created Zarins Beautylab because of my love for cosmetics, skin care products and all other stuff that makes me (and you) look and feel beautiful. My semesters of chemistry courses come in handy as I explain the science behind different beauty products: which works and how it works. Well, Sometimes its science and sometimes its just good ol’ common sense.

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