There is already plenty of evidence that broad-spectrum sunscreen helps prevent sunburns, which in turn are linked to an increased risk for skin cancer. Now, however, an Ohio State University study has found a direct connection between sunscreen application and skin cancer prevention.
The study used genetically engineered mice who would spontaneously develop melanoma (a form of skin cancer) about 26 weeks after the application of a specific chemical compound (4OHT). These mice were divided into two groups: one that was exposed to ultraviolet-B light once a day, and another that was exposed to the same amount of UVB light, but only after the application of sunscreens containing UV-blocking agents.
Researchers discovered that cancerous melanoma growths appeared much more rapidly in the mice who were not covered in sunscreen. For the mice who were covered in sunscreen protection, melanoma onset was significantly delayed and tumor incidence was reduced.
This study reinforces the importance of regular sunscreen application, especially for people who have pale skin or a personal or family history of skin cancer.
How Melanoma Develops
There are several different types of skin cancer. Basal cell carcinoma is the most common form, and while it usually doesn’t spread, it does require treatment. Melanoma is less common, but it’s also the most dangerous form of skin cancer.
Melanoma starts in the skin cells that make up our pigment and may occur after overexposure to UV rays (i.e. too much time in the sun or tanning bed) damages the skin cells’ genetic makeup (DNA). Too much DNA damage can lead to abnormal cell growth, which can become cancer.
Melanoma typically first appears as a mole, and the mole and surrounding skin can be removed if caught early enough. However, if not caught, cancer cells can move to lymphatic or blood vessels, where they can travel to and infect different parts of the body.
Melanoma Skin Cancer Stages
How Sunscreen Works
Melanoma is obviously something that everyone should strive to avoid, and as the recent study from Ohio State University shows, sunscreen (ideally SPF 30 or higher) can help.=
Sunscreen contains several different ingredients that help prevent damage from UV rays. Organic sunscreen chemicals absorb UV energy before they reach the skin and release the absorbed energy as heat (however, wearing sunscreen shouldn’t make you feel noticeably hotter). Inorganic sunscreen chemicals partially absorb UV waves, but also deflect them so that they don’t reach your skin.
Keep in mind that just spreading a dab of sunscreen on your nose at the beach isn’t enough to provide adequate protection. You’ll need approximately 2mg of sunscreen per square centimeter of skin—according to Wired, that comes out to about a shot glass’ worth of sunscreen for your arms, legs, torso, and face. Your skin will need about 15 minutes to absorb this sunscreen, so you should ideally apply it before you go out in the sun. You also need to remember to reapply your sunscreen every two hours.
