The Importance of Wearing Sunscreen

Being outside in the sun has several benefits; it helps the body produce vitamin D, boosts mood, and helps regulate the body’s natural sleep/wake cycle. However, the sun can also cause skin damage, including premature aging and skin cancer. Wearing sunscreen can help mitigate these effects.

How the sun affects the skin

• The sun produces ultraviolet (UV) radiation. When UV rays reach the skin, the skin makes more melanin. Melanin is the pigment that colors the skin.
• After exposure to UV rays, changes in skin color occur, which is a sign of injury to the skin (either a sunburn or a tan). A sunburn occurs when the amount of damage to the skin is greater than the protection melanin can provide.
• Most of the UV radiation that reaches the skin is ultraviolet A (UVA) radiation, but a small percentage is ultraviolet B (UVB) radiation. While ultraviolet C (UVC) radiation exists, it is filtered out by the earth’s atmosphere and does not reach the surface.
• Although UVB makes up a smaller percentage of total UV radiation, it is most responsible for causing sunburns and skin cancer, including melanoma and carcinoma. Some types of skin cancer can spread to the lymph nodes or other parts of the body and can be fatal. Approximately 20% of Americans will develop some type of skin cancer in their lifetime.
• UVA primarily affects the appearance of the skin. Prolonged exposure can cause skin aging, wrinkles, loss of elasticity, and age spots. It can also cause skin cancer.

How sunscreen can help

Sunscreens contain filters that absorb UV radiation or reflect it away from the skin. There are two types of filters: organic and inorganic.

• Organic filters include chemicals such as oxybenzone, avobenzone, and octocrylene. These chemical sunscreens absorb UV radiation and convert it into heat. Some of these chemicals absorb UVA radiation but do not absorb UVB radiation. For this reason, “broad spectrum” sunscreens that filter both UVA and UVB radiation should be used.
• Inorganic filters, such as zinc oxide and titanium dioxide, protect the skin by reflecting and scattering UV radiation away from the skin. Sunscreens containing inorganic filters are known as physical sunscreens and may provide more broad-spectrum protection against both UVA and UVB rays than organic filters.

Using sunscreen can reduce the appearance of aging and significantly reduce the risk of developing skin cancer. A sunscreen with broad-spectrum protection and a sun protection factor (SPF) of 30 or higher is best. It’s important to apply sunscreen 15 to 30 minutes before going outdoors, even on cloudy days. Sunscreen should be reapplied at least every two hours (more frequently if swimming or sweating).