Fact or Fiction: Does the Sun Cause Aging?

After a long winter spent stuck inside, or even just a day in an office that’s blasting the AC, nothing feels better than the warm rays of the sun on your skin. The sun plays a vital role in our daily lives. Besides the fact that it’s responsible for all plant life on Earth (no big deal!) the sun also provides our bodies with Vitamin D, an essential vitamin that impacts our mood, bone health, and immune system.

The sun’s harsh rays aren’t all beneficial, though. Too much sun exposure can cause premature aging, burns, sun poisoning, and even skin cancer — a process called photoaging. But why does the sun affect our skin so much? And how can we enjoy time spent in the sun without prematurely aging our skin?

UVA vs UVB rays: What is the difference?

When we expose ourselves to the sun, we expose ourselves to ultraviolet radiation. Ultraviolet radiation or UV radiation comes in two forms: ultraviolet A and ultraviolet B. The majority of radiation that reaches earth is in the form of UVA rays, although UVB rays are also present. 

UVA rays are associated with skin aging, while UVB rays are associated with skin burning. These rays are so powerful that they impact our cells on a genetic level, and the key to preventing photoaging and associated risks lies in understanding their differences.

UVB rays are more intense than UVA rays, and can cause sun tans, burns, and even blistering. They’re strongest during the mid-morning to afternoon, and intensify in temperate climates between the spring and fall. 

Although UVA rays aren’t as intense as UVB rays, they do penetrate the skin more deeply, causing genetic damage to the innermost cells of the top layer of skin. UVA rays contribute to tanning and in some cases burns. UVA rays are also present in tanning beds. 

Even if you don’t burn when you get a tan, UVA rays can still cause skin cancer and other symptoms of photo aging. And unlike UVB rays, you can experience damage from UVA rays all year long, even in the winter. They can even penetrate windows and cloud cover. 

The impact of UV radiation on skin aging

UVA rays penetrate both the dermis and the epidermis, the outermost and deepest layers of your skin. The health of the dermis contributes to smooth and young looking skin, while the health of the dermis promotes collagen and elastin production.

If you’re regularly exposing yourself to UV radiation without protection, you might lose collagen and elastin in your skin earlier than you would in the aging process. Elastin levels impact your skin’s ability to stretch, while collagen keeps your skin looking plump and smooth.

UVA radiation induces radical oxygen species (ROS) into the human skin. ROS levels rise naturally as we age, leading to collagen degradation. You might not notice the impacts in the short term: collagen cells are able to repair themselves, but are damaged as a result. Over time this damage can cause the skin’s vital functions to self-repair in a way that reduces collagen production, and leads to prematurely aged skin.

Symptoms of photoaging

While the damage from photoaging might be invisible as it’s happening, it eventually appears very visibly on the body, especially in areas that are most exposed to the sun like your face, neck, chest, and hands. 

Photoaging leads to wrinkles on the forehead and around your mouth and lips, reduced elasticity, thinner skin, and even broken capillaries on your nose, cheeks, or neck. Damage from UV rays is also the leading cause of skin cancer, including melanoma. 

How to protect yourself from UVA and UVB rays

So, it’s a fact: sun exposure—even in winter months, even when you don’t get a burn or even a tan—leads to premature aging. Luckily, there are ways to protect ourselves from UV radiation and reduce the harmful impacts of it on our skin.

Wearing daily SPF on not only your face, but your entire body, can protect your skin from photoaging and skin cancer. Make sure to reapply sunscreen every 2 hours, and try to stay out of the sun when UVB rays are the strongest. And while SPF does prevent your skin from absorbing Vitamin D from the sun, you can always supplement your diet with pills or monthly injections to maintain healthy levels of Vitamin D.

When choosing a sunscreen make sure to look for a sun protection factor (SPF) of 15 or higher. The sun protection factor on a bottle of sunscreen is linked to UVB rays, and delineates how long it will take for the sun’s radiation to burn your skin in comparison to not wearing sun protection at all. 

At one point, the medical community believed that UVA rays were safe, so earlier formulations of sunscreen didn’t protect from them. Today, sunscreens that protect from UVA rays are called broad spectrum sunscreens, and are advertised as such on the bottle. A sunscreen like ELTA MD Broad Spectrum 46 SPF offers both a high level of SPF and broad spectrum protection to prevent damage from UVA and UVB rays.