Can Sunscreen really Prevent Wrinkles and Cancer?
It’s summer, and before you head outside to go to the beach, pool, or just exist under the sun, you slather on sunscreen. Is sunscreen prevent wrinkles? What about skin cancer?
Sunscreen commercials have been around for almost a century, but before diving into what sunscreen does, we need to understand why the sun’s rays can give us wrinkles, cancer, or make us look like a steamed lobster if we’re outside too long.
Earth’s ozone layer filters out UVC, so it can’t reach us. This leaves UVB and UVA.
UVB rays have a short wavelength, so they don’t penetrate deeply into your skin. They don’t get past the top layer (your epidermis) and are mostly responsible for sunburn. However, UV radiation releases compounds like cytokines in your epidermis, which travel to the dermis (the layer below). There, they cause blood vessels to dilate, increasing blood flow. This is why fair-skinned individuals often appear pink or red after sun exposure.
Sunscreen prevent wrinkles
People with darker skin have more melanin, a brown pigment that not only gives a tan but also offers some protection against skin damage. This makes increased blood flow harder to notice in darker skin tones. However, it’s a common (and incorrect) assumption that darker skin can’t burn—it can, though the signs might be less visible.
It’s also worth noting that sunscreens were historically developed with fair skin in mind. Although more companies are now creating products tailored for a range of skin tones, there’s still progress to be made to ensure inclusivity for darker-skinned individuals.
UV Damage and Cancer
When UVB radiation hits your skin, it does more than cause a sunburn—it damages DNA, which can lead to skin cancer. Here’s how:
Your DNA has four nucleotides: adenine, cytosine, guanine, and thymine. UVB radiation can cause cytosine or thymine to bind to a neighboring nucleotide, forming cyclobutane pyrimidine dimers (CPDs). These CPDs warp your DNA’s structure, preventing enzymes from properly reading and transcribing it into RNA.
To fix the damage, your body removes the faulty DNA segment and rebuilds it using the opposite DNA strand. However, this repair process isn’t perfect and can lead to mutations. Most mutations are harmless, but if they occur in genes that control cell growth (like P53), cells may start dividing uncontrollably, potentially leading to cancer.
UVA rays can also contribute to cancer, though not directly like UVB. Both UVA and UVB generate reactive oxygen species, which can damage DNA by adding oxygen atoms. For example, guanine can be oxidized into 8-oxo-7,8-dihydroguanine, disrupting its ability to pair correctly with cytosine. This damage can also result in uncontrolled cell division.
UV and Wrinkles
Most of the sun’s rays that reach the Earth’s surface are UVA. These rays have longer wavelengths, allowing them to penetrate deeper into the skin (to the dermis). There, they trigger melanocytes to produce melanin and contribute to wrinkle formation.
Over time, everyone develops wrinkles, but UV radiation—particularly UVA—accelerates the process. It increases the production of enzymes called metalloproteinases, which break down collagen and elastin fibers. These fibers provide structural support and elasticity to the skin, so their degradation leads to wrinkles and leathery skin.
Some studies have found that UV exposure increases elastin production, but the elastin produced is abnormal, resulting in improperly rebuilt skin. This also contributes to wrinkles.
Can Sunscreen Prevent Wrinkles and Cancer?
If sunscreen blocks most UV rays—and we know UV rays cause wrinkles and skin cancer—it’s logical to say yes, sunscreen can help prevent both. However, data on this is limited.
In the 1990s, a randomized controlled trial in Australia followed 903 adults over 4.5 years. Researchers found that participants who used sunscreen daily showed no detectable increase in skin aging (based on silicone impressions of their hands). The study also found a reduced risk of certain types of skin cancer.
Although the data is limited, it suggests that sunscreen can prevent wrinkles and skin cancer. Since then, sunscreens have become more protective, which is promising.
Most dermatologists recommend using sunscreen as part of a broader sun-protection strategy. Not all sunscreens are created equal, even those with the same SPF. SPF measures UVB protection, but it’s important to choose a sunscreen that also shields against UVA rays. Look for broad-spectrum protection, and pair sunscreen use with other precautions, like avoiding peak sun hours and wearing protective clothing.
Sunscreen: Stronger Rules, Better Protection
The FDA is changing sunscreen labeling to make it easier for everyone to protect themselves from harmful sun rays. We encourage consumers to use broad-spectrum sunscreens labeled with an SPF value of at least 15. These sunscreens help reduce the risk of sunburn, skin cancer, and early skin aging when used as directed alongside other sun protection measures.
For the best protection, limit your exposure to the sun by wearing protective clothing, seeking shade, or staying indoors—especially between 10 a.m. and 2 p.m., when the sun’s rays are strongest.
Many people are familiar with SPF values, which refer to protection against sunburn. However, the term “broad spectrum,” which may be less familiar, indicates protection from the sun’s full range of harmful rays. These rays can cause not only sunburn but also skin cancer and early aging, such as wrinkles. It’s important to guard against all types of sun damage, not just sunburn.
The FDA’s new labeling requirements will make it easier for consumers to choose the best protection. Starting in 2012, manufacturers are required to prove all broad-spectrum claims. Only sunscreens labeled as both broad spectrum and with an SPF of at least 15 can protect against the sun’s full range of harmful rays when used as directed with other measures.
Sunscreen Protection:
The FDA has found no evidence that SPF values above 50 provide any additional benefits. Additionally, terms like “waterproof” or “sweatproof” are no longer allowed on sunscreen labels, as no sunscreen is entirely waterproof. Sunscreens labeled as “water-resistant” must specify how long the water resistance lasts (e.g., 40 or 80 minutes). If this language is missing, the product is not water-resistant.
When using spray-on sunscreen, avoid inhaling it and do not spray it directly onto your face. Always follow the directions on your sunscreen product. This includes applying and spreading it thoroughly and reapplying it at least every two hours—or more often if you’re sweating or frequently going in and out of water.
While protective clothing and limited sun exposure remain the best ways to shield yourself, improvements to sunscreen labels will make it easier to use these products safely and effectively.
What’s Harmful About Sunlight?
Sunlight is composed of photons of light. The visible photons we can see aren’t a problem, but the UV (ultraviolet) photons, beyond indigo and violet on the spectrum, are much higher in energy. These can ionize molecules in our bodies and cause problems.
- UVC light has the highest energy and is the most damaging, but luckily, it’s almost entirely filtered out by the ozone layer.
- UVA penetrates deep into the skin, causing wrinkling and other signs of aging, which scientists call photoaging.
- UVB has higher energy than UVA and is the primary cause of sunburn.
All types of UV light can interact with DNA, potentially causing mutations that lead to skin cancer.
How Does Sunscreen Protect You?
Sunscreen acts as a chemical filter that absorbs or reflects UV photons before they reach your skin. Historically, sunscreens focused on UVB protection to prevent sunburn, but many modern sunscreens also protect against UVA, which has been linked to accelerating skin cancer development.
Sunscreens that protect against both UVB and UVA are labeled broad-spectrum.
What Do SPF Ratings Mean?
SPF ratings indicate how much longer sunscreen can delay sunburn compared to bare skin. For example:
- Without sunscreen, it might take 10 minutes in the sun to start getting a sunburn.
- With SPF 15, it would take 150 minutes (10 × 15).
- With SPF 50, it would take 500 minutes (10 × 50).
However, sunscreen protection depends on proper application, and most people don’t use enough to achieve the advertised SPF.
Sunscreen Application Tips
- Apply sunscreen generously and evenly.
- Reapply every two hours or more often if swimming or sweating.
- Don’t forget areas like the top of your head, ears, and feet.
Sunscreen and Tattoos
Tattoos don’t protect your skin from UV damage. In fact, some dermatologists believe tattoos can make it harder to spot skin cancers. Always cover tattoos with sunscreen to keep them and your skin safe.
What About Clothing?
Clothing can provide additional UV protection. Its effectiveness is measured by UPF (Ultraviolet Protection Factor). Factors like color, weave, and material affect a garment’s UPF. For instance, a plain white T-shirt might only have a UPF of 5, while blue denim offers much better protection.
The Future of Sun Protection
Scientists are exploring pills, drinks, and DNA-based films as potential UV blockers. However, none of these options have been proven effective for long-term use.
Stay Safe in the Sun
Until new innovations emerge, the best way to protect yourself remains the same:
- Use broad-spectrum sunscreen with at least SPF 30.
- Wear protective clothing, hats, and sunglasses.
- Seek shade and avoid peak sun hours (10 a.m.–2 p.m.).
By following these simple rules, you can enjoy the sunshine while keeping your skin healthy and safe.