The Myth of the ‘Base Tan’
It’s the myth that just won’t die: You need a “base tan” to start the summer season and help protect you against sunburn. This belief is not only false, but it’s also dangerous. Because May is Skin Cancer Awareness Month, our family practice doctors in Delray Beach want to take this opportunity to put an end to this common fallacy.
The facts behind the myth
The myth of the “base tan” persists because it seems logical. If you already have a tan, you’ll be less likely to burn on your tropical vacation. There is actually a grain of truth to this: lying in the sun with a tan is equivalent to wearing a sunscreen with a sun protection factor (SPF) of 3 or 4. That means, if you would normally burn in 10 minutes with totally untanned skin, you could spend three or four times that amount—thirty to forty minutes—in the sun before you begin to show signs of a burn.
This is just a fraction of the protection you receive from a good sunscreen, however. If your sunscreen has, for example, an SPF of 15, that means that if you’d normally burn with ten minutes’ exposure to the sun, an SPF of 15 would allow you to safely stay in the sun for 15 times longer than that, or 150 minutes. Most dermatologists recommend a sunscreen with an SPF of at least 30, preferably higher, but even the best sunscreens will not prevent sunburn if you stay out in the sun long enough.
What you can’t see is the damage that’s occurring to your skin with every minute you spend exposed to UV light. Any change in skin color is a sign that your skin has been damaged. And suntanned skin will still burn; it just won’t be as immediately apparent.
The sun-skin cancer connection
Researchers have known for decades about the link between UV exposure and skin cancer. And that doesn’t just mean melanomas, the most deadly kind of skin cancer. Studies have also shown a correlation between UV exposure and squamous cell and basal cell skin cancers. In the United States, the number of new cases of melanoma has more than doubled in the past 20 years.
Whether from the sun or a tanning booth, UV light causes DNA mutations in the melanocytes, the pigment in the lower part of the epidermis, becomes malignant, meaning that they begin to divide uncontrollably. If it reaches the lymph nodes, it can then spread to other parts of the body.
Staying safe year-round
Experts recommend to following steps to stay healthy:
- Avoid exposing your skin to the sun between 10 a.m. and 4 p.m. when the sun’s rays are strongest.
- Avoid indoor tanning beds
- Cover up exposed skin with tightly-woven fabrics or those designed to provide UV protection (including on your head) while outdoors. Wear a broad-brimmed hat and sunglasses.
- Use a broad-spectrum sunscreen with at least a 30 SPF whenever you are outdoors, even on cloudy days. Apply it 15 to 20 minutes before going outside, and reapply it every two hours—more often if you’re swimming or perspiring heavily.
- Be aware that UV rays can not only penetrate glass, but can “bounce” under beach umbrellas and reflect off water and concrete surfaces.
- Forget about a “base tan.” It won’t prevent sunburn and it will damage your skin.
Skin cancer is the most common form of cancer diagnosed in the United States. If you have any questions about this often-deadly disease, please contact us.