Are there different types of sunblocks?
That suntan that used to be fashionable (and still is in some circles) is a signal that the UV in the sunlight has damaged your DNA. Nothing to celebrate, right?
Ultraviolet light is classified into three categories: UVA (315 to 400 nm), which causes tanning, UVB (medium wave, 280 to 315 nm), which causes sunburn, and UVC (short wave, germicidal, 100 to 280 nm), which is filtered out by the atmosphere and does not reach us. Incidentally, the ozone (O3) layer of the atmosphere absorbs 97–99% of the UV in the range 200 nm to 315 nm, which is why the destruction of the ozone layer by some chemicals is dangerous for life on earth. The lower the wavelength, the higher the energy. Some organisms, like plants, can convert the energy of light into something useful, like carbohydrates in a process called photosynthesis (you learn about this is high school, but it is still relevant). Humans can’t do anything remotely useful with light energy, although tiny amounts of light regulate some biological processes. For example, our hypothalamus regulates circadian rhythm via the retina, the receptor. The UV side of the light spectrum packs more energy than, say, red or yellow light. More energy, more damage.
Does it matter which part of the UV part of the spectrum did the damage? Yes and no. Damage is damage. But the damage to protein will end with that protein, while damage to DNA can perpetuate itself.
The more we learn about sunlight and its interaction with the skin, the more we realize that complexity matters. The wavelength of the UV will determine how far it will go and how it will interact with the macromolecules in the skin. Will it produce sunburn? Will it increase DNA mutation (and, possibly, skin cancer)? The amount of damage depends not only on the amount of energy. which depends on the wavelength, shorter wavelength, more energy. It also depends on whether that wavelength is absorbed preferentially by a particular molecule, and that will depend on the chemical structure. But those are matters for the scientists to discuss. As humans exposed to the sun and other sources of UV like sunbeds, those are minutiae: apart from the small amounts of light that we need to function, the excess, especially when that excess is in the form of high energy ultraviolet light, is BAD.
Let me count the ways UV light hurts us:
A sunburn hurts
UV damages DNA, which encodes proteins. Faulty DNA means faulty protein.
Melanin absorbs UV, and this excited melanin instead of dissipating the energy as heat (a benign process) reacts with another molecule, say a protein, and initiates a chain of events that results in the formation of ROS*
…and when ROS* are involved, the damage goes on and on because ROS* initiate chain chemical reactions, like in a billiards table. You don’t want your invaluable DNA to be treated this way. Keep accumulating DNA mutations and next, your precious cells degenerate into monsters that divide quickly and destroy your healthy cells.
Our bodies have the means to correct almost anything, including DNA mutations. And they do fix DNA mutations but… not all. And damage accumulates until our beautiful young skin ages, wrinkles, pigmentation goes haywire and eventually,
What can you do about sun damage? First, prevent. With sunscreen and/or avoiding the sun.
Sunscreen: a lotion that contains ingredients capable of absorbing or reflecting UV radiation before it reaches the skin thus preventing burning and photoaging.
Thankfully, part of the public has been educated about the dangers of sun exposure and tanning oil has all but disappeared from the market. The general population has evolved from wanting to promote or enhance a suntan to wanting to prevent tanning or burning. For skin that has seen too much sun and experienced sunburns, our UV Repair Cream will help.
The main agent of skin aging is UV radiation. Wear sunscreen, ours, or any sunscreen that provides substantial protection. Remember that sunscreens do not prevent damage completely, but they extend the time of exposure before your skin gets damaged.
Physical (mirrors) zinc oxide and titanium dioxide, which stay on the surface of the skin and mainly deflect the UV light
Chemical sunblocks, which absorb UV and dissipate the energy in a less damaging way (like heat)
The principal active ingredients in sunscreens are usually aromatic (aromatic in the organic chemistry sense, not smell) molecules conjugated with carbonyl groups. This general structure allows the molecule to absorb high-energy ultraviolet rays and release the energy as lower-energy rays, thereby preventing the skin-damaging ultraviolet rays from reaching the skin. So, upon exposure to UV light, most of the ingredients do not undergo a significant chemical change, allowing these ingredients to retain the UV-absorbing potency without significant photodegradation.
Blume C, Garbazza C, Spitschan M. Effects of light on human circadian rhythms, sleep and mood. Somnologie (Berl). 2019;23(3):147-156. doi:10.1007/s11818-019-00215-x
Skin Actives products that can help with sun damage
https://skinactives.com/sunscreen-spf-30-advanced-protection/
https://skinactives.com/daily-defense-anti-aging-day-cream-with-spf-30/
https://skinactives.com/uv-repair-cream/
DISCLAIMER: These claims have not been evaluated by the FDA and are not intended to diagnose, cure, treat or prevent any disease.