Sunscreen myths and truths
August 15, 2016
Are you in the dark about sun protection? A Kaiser Permanente dermatologist separates fact from fiction.
You're wearing sunscreen — that's great! It can help you avoid wrinkles, sunspots, and skin cancer. Just be forewarned that it doesn't give you free rein for endless alfresco fun. Kaiser Permanente dermatologist Nicole Annest, MD, sheds light on a few falsehoods that prevent optimal protection.
Myth: I don't need to wear sunscreen when it's cloudy.
Truth: Shade does not completely protect from ultraviolet (UV) light. In fact, 50 percent of UV exposure on sunny days occurs when in the shade.
Myth: A sunscreen with SPF 30 gives me twice the protection as SPF 15.
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Truth: Sun protection factor (SPF) does not increase proportionally. SPF 15 absorbs 93 percent of UV radiation, while SPF 30 absorbs 97 percent. I recommend "broad spectrum" SPF 30 sunscreen to block both UVA and UVB rays.
Myth: A little dab'll do ya.
Truth: Most people apply 25 to 50 percent of the recommended amount of sunscreen, so the SPF becomes far less than what is on the bottle. You need 1 ounce — enough to fill a shot glass — to get full protection.
Myth: I need a base tan before I go on vacation.
Truth: A base tan is approximately SPF 2, so it's not very protective. Furthermore, a tan is really just a sign of skin damage.
Myth: I have dark skin, so I can skip the sunscreen.
Truth: Although it is more protected from ultraviolet light, darker skin is still susceptible to the harmful effects of the sun. I frequently treat skin cancer in patients with darker skin types.
Made in the Shade?
Taking cover might not give us the relief we think. A recent article in the Journal of the American Academy of Dermatology examines the actual SPF of life in the shade.
SHADE SOURCE PROTECTION IT PROVIDES:
Shade umbrella SPF 4
Wide-brimmed hat SPF 2 for the chin; SPF 7 for the nose
Narrow-brimmed hat SPF 1.5 for the nose; minimal to no protection elsewhere
Makeup foundation without sunscreen SPF 2–6
Trees SPF 4–50+, depending on density of leaves
HOW WELL DO YOU KNOW YOUR SKIN?
Learn how to protect your skin from irritation, infection, and sun damage. Visit kp.org and search "learning about your skin."