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Sunscreen: It's all year round!

The harmful effects of UV rays on the skin are now known to everyone. While some people never leave the house without applying their sunscreen and don't hesitate to reapply it regularly even in the middle of winter, others deem it unnecessary except for sunny days and beach outings. What is the actual situation?

Summary
Published September 26, 2021, updated on October 2, 2024, by Stéphanie, Doctorate in Life and Health Sciences — 5 min read

Year-round Sunscreen: Opinions Differ.

The use of sunscreen throughout the year is a topic of debate. It is true that the harmful effects of UV rays on the skin are universally recognized: premature aging of the epidermis, appearance of pigmented spots and wrinkles, increased risk of skin cancer, skin burns, etc. However, many people believe that skin protection against ultraviolet rays is only necessary in cases of prolonged sun exposure (sunbathing on the beach, water activities, etc.) and only during the summer seasons. Indeed, some are still hesitant to apply sunscreens regularly.

To justify this, some believe that sunscreen should only be applied on sunny days and that it is unnecessary to apply it when it's cloudy since the sun is hidden, or even indoors because supposedly UV rays do not penetrate windows. Others point to the chemical ingredients that make up sunscreens. Indeed, some skin types may react poorly to certain substances found in some sunscreens. Additionally, the risks associated with the presence of endocrine disruptors in some sun protection products are a hot topic and deter some people. For these reasons, consumers prefer to limit their use to summer afternoons.

Why should you apply sunscreen?

Contrary to popular belief, UV rays can penetrate clouds and even windows (particularly UVA rays). These rays are the number one enemy of the epidermis because:

  • They accelerate skin aging(thickening of the epidermis, skin dryness, loss of elasticity, appearance of wrinkles, fine lines, and brown spots, loss of radiance, dilation of blood vessels, etc...);

  • They are the cause of sunburns ;

  • They can cause a skin cancer ;

Thus, applying a sunscreen will create a protective shield against UV rays. It effectively prevents UVA and UVB rays from penetrating the skin and causing damage.

If you're still not convinced about the harmful effects of the sun on the skin, take a look at this photo. It's a portrait of a 69-year-old milk delivery man who spent 28 years behind the wheel. The left side of his face has aged rapidly due to sun exposure (photo-aging). Indeed, this part of his face was regularly exposed to UV rays through the window of his truck. While his right profile appears much less marked, smoother, and healthier, his left face is more damaged, wrinkled, the skin is thicker and sagging, and the grooves are more pronounced. These marks were caused by UVA rays, which can penetrate deeply into the skin beyond the epidermis where they are capable of destroying elastin and collagen fibers, and altering DNA.

This is why it is important toapply sunscreen every day and to reapply it regularly (every two hours) for optimal skin protection against the harmful rays of the sun, especially when the sun is at its zenith, that is, between 11 a.m. and 3 p.m. This is the time when the rays are most dangerous, especially if you are outdoors. Moreover, do not neglect any part of the body that can be directly exposed.

BRIEVA J. C. & et al. Unilateral dermatoheliosis. The New England Journal of Medicine (2012).

Sources

  • BRIEVA J. C. & al. Unilateral dermatoheliosis. The New England Journal of Medicine (2012).

  • BUABBAS H. & al. Photoprotection: clothing and glass. Dermatologic Clinics (2014).

  • WHITEMAN D. & al. Cancers in Australia linked to exposure to solar ultraviolet radiation and preventable through regular use of sunscreen. Australian and New Zealand Journal of Public Health (2015).

  • LIM H. W. & al. Sunscreens: An Update. American Journal of Clinical Dermatology (2017).

  • LINOS E. & al. Sunscreens, cancer, and protecting our planet. The Lancet Planetary Health (2018).

  • WHITEMAN D. C. & al. How many melanomas could potentially be prevented if more people consistently used sunscreen? British Journal of Dermatology (2018).

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