Exposure to the sun’s rays is the #1 cause of skin aging via oxidative stress and inflammation. Sunscreens are FDA-approved over-the-counter products used for the prevention of skin cancer and early signs of aging when used in conjunction with limiting sun exposure and wearing protective clothing.
Sunlight consists of two types of harmful rays that reach the earth—UVA rays and UVB rays—both ultimately lead to premature aging and wrinkles and to the development of skin cancer.
UVA rays (or aging rays) can prematurely age your skin, causing wrinkles and age spots, and can pass through window glass.
UVB rays (or burning rays) are the primary cause of sunburn and are blocked by window glass.
But did you know that photoaging mainly results from daily exposure to low doses of UV radiation, which does not cause visible changes at the time of exposure but leads to greater biological changes over time. In fact, 80% of facial aging is believed to be due to daily, chronic sun exposure, what is known as incidental sun exposure from everyday activities—walking the dog, retrieving mail, driving in the car, etc.
How do sunscreens work?
Sunscreen formulations generally combine several ingredients that help prevent the sun’s UV rays from reaching the skin. There are two types of sunscreen actives available:
Mineral sunscreens protect your skin from the sun by reflecting as well as absorbing the sun’s rays. They contain minerally sourced particles such as zinc oxide and titanium dioxide and form a shield over the skin that helps prevent UV light from penetrating the skin. Mineral sunscreens are ideal for sensitive skin.
Chemical sunscreens work by chemically absorbing the sun’s rays, preventing them from penetrating the skin. They contain synthetic compounds like Avobenzone or Homosalate that help prevent damage by transforming UV rays into non-damaging forms of energy, like non-UV light or heat. They are also known as organic sunscreens and are often combined to provide more complete protection.
A broad spectrum sunscreen protects you from both UVA and UVB rays. SPF stands for Sun Protection Factor. SPF is a measurement of how much protection a sunscreen has against sunburn. Applying a sunscreen with an SPF of 15, for example, means that it will take 15 times longer for your skin to burn that it would without sunscreen.
Below is a list of other common skincare product types.