Over the years, the sun has been associated with a multitude of positive things, from joyful summer days to glowing, tanned skin. However, sun exposure also carries health risks, especially for the skin. One of the best ways to protect your skin against these risks is by using sunscreen. This article explores the importance of sunscreen for skin protection. NAJDA
Understanding Ultraviolet Rays
Solar energy, which reaches us in the form of visible light, also brings along less perceivable but potentially harmful radiation: ultraviolet rays (UV). These rays, which are part of the sun’s electromagnetic spectrum, are invisible to the naked eye, but their impact on the skin is undeniable and can be devastating.
UV rays are classified into three categories based on their wavelength: UVA, UVB, and UVC rays. UVC rays, which have the shortest wavelength and are therefore the most energetic, are fortunately almost entirely absorbed by the Earth’s atmosphere, particularly by the ozone layer, and thus pose no direct threat to our skin. However, UVA and UVB rays, although less energetic, manage to reach the Earth’s surface and can cause significant damage to the skin.
UVA Rays:
Which have a longer wavelength, are less energetic than UVB rays, but they penetrate deeper into the skin. They can reach the dermis, the thickest and deepest layer of the skin. In the dermis, UVA rays can affect cells called fibroblasts that produce collagen, an essential protein for skin structure and elasticity. Collagen degradation due to UVA exposure can lead to premature skin aging, characterized by wrinkles and loss of firmness. Additionally, UVA rays can alter the DNA of skin cells, which can contribute to the development of skin cancer.
UVB Rays:
In contrast, have higher energy than UVA rays and are primarily absorbed by the epidermis, the superficial layer of the skin. UVB rays are directly responsible for sunburn, the painful acute inflammatory reactions of the skin to excessive sun exposure. Furthermore, like UVA rays, UVB rays can also cause damage to the DNA of skin cells, increasing the risk of skin cancer, particularly basal cell carcinoma and melanoma, the most dangerous form of skin cancer.
The Impact of Ultraviolet Rays on the Skin
The detrimental effects of ultraviolet rays: from premature aging to skin cancer
Ultraviolet rays, although invisible to the human eye, have a significant impact on our skin in various ways. Repeated and unprotected exposure to these rays can lead to a multitude of skin problems, some of which are benign but bothersome, while others are potentially life-threatening.
Beyond sunburn, the acute and painful inflammatory reaction to overexposure to the sun, UV rays can cause more subtle but progressive skin alterations. Age spots, also known as solar lentigines, are small pigmented spots that often appear on sun-exposed areas of the skin, such as the face, hands, or arms. While generally harmless, these spots are a visible sign of accumulated damage from UV exposure.
UV rays, particularly UVA rays, are also responsible for what is known as « photoaging. » This process results in drier, less elastic skin, more pronounced wrinkles, and a change in skin texture. Indeed, these rays damage fibroblasts, cells responsible for the production of collagen and elastin, essential elements for the suppleness and youthfulness of our skin.
However, the most serious consequences of UV exposure involve the alteration of the DNA of skin cells. This mechanism can lead to the development of skin cancers. This process occurs in two steps: first, UV rays cause direct and indirect changes to the DNA of cells. If these lesions are not properly repaired, they can cause genetic mutations, which, in turn, can lead to uncontrolled cell proliferation, a characteristic sign of cancer.
How Sunscreen Protects the Skin
Sunscreens play a crucial role in protecting our skin against UV rays. They actually act as a sort of shield, intercepting these rays before they can reach our skin and cause damage.
To understand how this works, it’s helpful to take a look at the composition of these sunscreen products and how their ingredients interact with UV rays.
Sunscreens are composed of two types of filters: organic and inorganic. Organic filters, sometimes called chemical filters, are capable of absorbing UV rays. When a UV ray encounters one of these filters, it is transformed into heat and dissipated, thus preventing the ray from penetrating deeper into the skin and causing damage.
On the other hand, inorganic filters, also known as physical or mineral filters, have a different mode of action. Rather than absorbing UV rays, they reflect them, like a mirror, thereby deflecting the rays away from the skin.
The application of sunscreen creates a protective barrier that acts as a screen, either absorbing or reflecting UV rays.
In doing so, sunscreen provides an additional layer of defense for our skin, reducing the risk of sun exposure-related damage.
It’s important to note that for this protective screen to be effective, sunscreen must be properly applied and regularly reapplied, especially after swimming or engaging in physical activity.
Choosing the Right Sunscreen
Choosing a sunscreen can sometimes seem bewildering. With so many products available in the market, all promising the best sun protection, how do you make the right choice? When selecting a sunscreen, two key elements should grab your attention: the sun protection factor (SPF) and broad-spectrum protection.
The sun protection factor, or SPF, is an index that measures the effectiveness of a sunscreen in blocking UVB rays, which are primarily responsible for sunburn. The higher the SPF, the stronger the protection against UVB rays. However, it’s important to understand that increasing protection is not proportional to increasing SPF. For example, an SPF 30 sunscreen blocks approximately 97% of UVB rays, while an SPF 50 blocks about 98%. The American Academy of Dermatology recommends using sunscreen with an SPF of at least 30 for sufficient protection.
Proper Application of Sunscreen
Once you have chosen the right sunscreen, the next – and equally crucial – step is knowing how and when to apply it correctly. Proper application of sunscreen is key to reaping the optimal protection the product can offer.
To start, sunscreen should be applied generously. Insufficient amount of sunscreen significantly reduces the level of sun protection. According to the Skin Cancer Foundation, it takes about an ounce of sunscreen, which is equivalent to a shot glass, to cover the entire body. This rule is easy to remember and helps ensure you’re using enough product.
The timing of application is also crucial. Sunscreen should be applied to all exposed areas of the skin approximately 15 to 30 minutes before going out in the sun. This allows the skin to absorb the product and maximize its protection.
However, sunscreen application doesn’t stop after the first coat. It’s important to reapply it at least every two hours, and immediately after swimming, heavy sweating, or towel drying.
Even « water-resistant » sunscreens need to be reapplied after swimming or sweating to ensure continuous protection.
Lastly, when applying sunscreen, it’s crucial not to neglect certain often-forgotten areas, such as the neck, ears, back of hands, and tops of feet. These areas are just as susceptible to UV rays and deserve equivalent protection.
Sunscreens and Beyond
While sunscreens play a crucial role in skin protection, they should not be your sole line of defense against UV rays.
Other measures, such as wearing protective clothing, seeking shade during the sunniest hours of the day, and avoiding tanning beds, should also be part of your sun protection routine.
Using sunscreen is a vital element in protecting the skin from UV ray-induced damage.
By understanding the risks associated with sun exposure and taking steps to protect your skin, you can enjoy the sun while minimizing these risks. So, next time you head out, don’t forget your sunscreen – your skin will thank you.
