The American Cancer Society reports that more than two million diagnoses of skin cancer each year could be prevented by protecting the skin with sunscreen. Still, many of us head outdoors without applying. And, it turns out, those of us who do put on sunscreen are probably not doing it right.
I spoke with Dr. Adrienne Haughton, MD, a board-certified dermatologist and assistant professor of dermatology at Stony Brook University School of Medicine in Stony Brook, New York, to find answers to all your SPF (sun protection factor) questions—from how much SPF you need for your skin type to how to choose the best sunscreen for your lifestyle—so that you get the best protection for your buck.
What level of SPF should we be wearing on an everyday basis?
Dr. Haughton says, "The average person requires the equivalent of two tablespoons of sunscreen to adequately cover their body." The average person does not wear enough sunscreen and applies only 25 to 50 percent of the recommended amount. In one study, patients applying what they perceived as an adequate amount of sunscreen with a labeled SPF of 70 and 100 only provided an actual SPF of 19 and 27, respectively.
As a general rule, wear an SPF of 30 for daily use and 45 or higher if you are planning on being outside for a prolonged period of time. Daily SPF is essential; UVA rays come through window glass and are present even on a cloudy day. This is why many people in the United States develop skin cancer on the left side of their face and left arm due to exposure through the driver-side window.
Does skin type affect the level of SPF that we should be using? If so, what level of SPF is recommended for different skin types?
People with darker skin types have more melanin that provides a natural protection from the sun. African American skin, on average, has an SPF of 13.4 compared to 3.4 in Caucasian skin. So people of all skin types benefit from the recommendations outlined above. Total SPF is not cumulative, that is, if a person with fair skin and someone with dark skin both put on product with an SPF of 30, their maximum protection from the sun (UVB) is still 30. This also goes for layering products that contain sunscreen. If your moisturizer has an SPF of 15 and your foundation has an SPF of 15, your total SPF is still 15.
Is there anything else to consider when choosing an SPF?
SPF only assesses a product’s ability to protect against UVB radiation that causes sunburns. UVA radiation, which is less intense than UVB, is also damaging. It increases the risk for the development of skin cancer, penetrates deeply, and causes wrinkles. A broad-spectrum sunscreen will protect against both UVB and UVA rays.
Water-resistant products are effective for approximately eighty minutes of continual sweating and forty minutes of swimming. Therefore, water-resistant products should be reapplied frequently.
The least irritating sunscreens (best for children and those with sensitive skin) are those that have physical blockers such as titanium dioxide and zinc oxide.
Lastly, pick the application of sunscreen that works best for you. Sprays and gels are great for people on the go who do not want the possibility of sunscreen dripping into their eyes. Companies have come up with endless formulations so find products that work for your skin type and lifestyle.
Photo by Shannon Lee Miller