Sometimes, it can be challenging for patients to realize that not all signs of aging stem from growing older. Studies estimate that up to 80%-90% of visible aging stems from exposure to UV light. 

Photoaging refers to skin damage caused by both natural and artificial sunlight, such as that from tanning booths. While true that our skin naturally loses its plumpness and elasticity over time, UV light is a catalyst for the process. It also has a profound effect on your skin texture and tone. Of course, it can also lead to skin cancer. 

This is why SPF is the most crucial step in your skincare routine. Not only does it protect you from a potentially life-threatening disease, but it also helps you maintain your youthful complexion as you grow older. 

But how exactly does photodamage occur? 

UVA and UVB Rays

UV radiation consists of two different wavelengths of light: UVA and UVB. While both contribute to photodamage, each kind has particular effects on your skin because of differences in their wavelength. 

UVA rays are very long wavelengths from 320-400 nm. The longer wavelength allows them to pierce through all three layers of skin: the epidermis, the dermis, and the subcutis. It damages skin cells and destroys proteins in our skin matrix such as collagen and elastic fibers. 

UVA also fragments elastic fibers, causing them to clump and loose their recoil resulting in solar elastin.

Our skin tries to protect itself from UV rays by increasing its superficial dead layer, the stratum corneum, this results in a thickened, leathery texture.

UVA rays also causes blood vessels to dilate and even burst, leading to easier bruising and spider veins. 

Broad-spectrum sunscreen provides additional protection from UVA damage. 

UVB Exposure Changes Your Skin’s DNA

UVB rays have a very short wavelength from 280-320 nm, which means that instead of penetrating through the layers of skin, they hit at the surface. As they bombard your epidermis, our DNA absorbs the damage, transforming most of the radiation into a harmless form of heat. Unfortunately, it still takes a hit. Our DNA consists of base pairs of thymine dimers that bond together, but UVB light interrupts this process.

Typically, thymine bonds with adenine, but UVB exposure causes it to bond with other thymine bases. This triggers melanin production to block the effects and mutates the DNA strand, leading to the formation of sunburn. Over time, these mutations can turn into skin cancer. 

The effects of melanin production can appear in a variety of ways, including:

  • Dark spots
  • Freckling
  • Mottled pigmentation
  • Melasma

The SPF in sunscreen is a measure of how long the protectant can block out UVB radiation before it begins burning your skin. 

Skin Type Determines the Extent of Photoaging

No matter what your skin color, everyone is susceptible to photoaging. 

That being said, some factors have a more profound influence on the amount of damage your skin takes when you venture outside sans SPF. Skin types are classified according to the Fitzpatrick’s Scale, a measure of potential photodamage risk. 

  • Type I- Very fair skin, blue or green eyes, blonde or red hair; always burns and never tans. 
  • Type II- Fair skin and blue eyes; always burns, may tan to some extent.
  • Type III- Medium skin that might burn but develops an average tan.
  • Type IV- Light-brown skin that tans easily and rarely burns. 
  • Type V- Brown skin that tans very easily and never burns. 
  • Type VI- Dark brown or black skin that always tans very darkly.

The lower your type, the more likely you are to experience the damaging effects of UV light. 

SPF is Crucial to Maintaining Your Youth and Skin Health

The dangers of sun exposure go far beyond sunburn. As the years of damage accumulate, your skin has to contend with mutated DNA strands, malformed proteins, and weakened blood vessels. In addition to protecting yourself with a broad-spectrum sunscreen, you should also discuss the current state of your skin’s photoaging with your dermatologist. They can help you reverse the damage and keep an eye out for potential risks in the future. 

It is important too use a broad spectrum sunscreen that blocks both UVA and UVB daily. An SPF of 30 or is generally recommended. It is important to reapply sunscreen after excessive sweaty or being in the water.