Why is UV protection essential for protecting our skin?
By Manon, pharmacist · Founder of Éclairée
To understand the real impact of UV rays on our skin, Ker Sun draws on the expertise of Manon, pharmacist and founder of Éclairée. From the anatomy of the skin to the mechanisms of UV rays, Manon explains why sun protection is far more than a simple summer habit.
UV protection is now a major public health issue when we realise that the number of new skin cancer cases has more than tripled in 30 years (source: INCa).
To understand the impact of UV rays and why it is important to protect yourself from them, you first need to understand your skin: its structure and how it works.
Understanding Your Skin
The Anatomy of the Skin
The skin is our largest organ. It plays an essential role as a protective barrier against external aggressors, including UV rays.
It is made up of 3 main layers (from the outside in):
- The epidermis: made up of keratinocytes, which represent 90% of epidermal cells, melanocytes, which produce melanin, Langerhans cells, which play a role in the immune system, and Merkel cells, responsible for touch perception.
- The dermis: composed in particular of fibroblasts, which synthesise collagen, elastin and more.
- The hypodermis: made up mainly of adipocytes, the fat cells in our skin.
UV Rays
UV Rays and Their Effects on the Skin
There are 3 types of ultraviolet (UV) rays: UVA, UVB and UVC.
- UVA and UVB reach the Earth's surface and therefore our skin.
- UVC rays are absorbed by the ozone layer and do not reach the skin.
Understanding the difference between UVA and UVB helps explain why sun protection is essential.
UVA Rays
UVA rays account for 95% of UV radiation. They penetrate as far as the dermis.
They are responsible for accelerating skin ageing (more pronounced wrinkles, loss of elasticity, hyperpigmentation spots). UVA rays also photo-oxidise melanin and are responsible for immediate pigmentation, meaning the slight tan that appears just after sun exposure but disappears after a few minutes.
“UVA rays are responsible for around 35% of skin cancers.”
UVA rays also have the particular ability to pass through glass, which is why it is important to protect yourself from them even in the car, or indoors if the sun's rays reach your skin.
UVB Rays
UVB rays account for around 5% of UV radiation. They remain at the skin's surface, penetrating only as far as the epidermis.
They cause sunburn, tanning and 65% of skin cancers.
They also have a beneficial role: they enable vitamin D synthesis.
To produce a sufficient amount of vitamin D, it is recommended to expose yourself only 2 to 3 times a week. Fifteen minutes is enough to synthesise vitamin D. Beyond that, no additional synthesis is observed, which means that extending exposure brings no extra benefit.
The Major Risk
UV and Cancer
The two types of UV rays we have just described are the main cause of more than 80% of skin cancers, so it is vital to protect yourself from them.
+80 %
of skin cancers are mainly caused by UV rays
Good Habits
How Can You Reduce UV-Related Risks?
It is essential to use optimal sun protection as soon as the UV index is 3 or above. To check the UV index in real time, simply consult your weather app.
Here is the recommended protection:
- A wide-brimmed sun hat
- Sunglasses (category 3 minimum)
- Covering UV protection clothing where possible, to absorb even more UV radiation
- Sunscreen on any parts of the body that remain uncovered
Key Takeaway
Optimal sun protection against UV rays is essential to help prevent skin ageing and reduce the risk of skin cancer.
Manon
Pharmacist · Founder of Éclairée
Source: French National Cancer Institute (INCa) - Epidemiology of skin cancers.
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