Sunscreen skeptics take note: The sun’s UV rays are attacking you, and you’re just making it easier for them.
Summer is here, which means more time in the sun and more exposure to the ultraviolet rays it emits. Longer-wavelength ultraviolet A rays can penetrate beneath the skin’s surface, causing premature aging. Shorter-wavelength ultraviolet B rays affect the outermost layers of skin, causing sunburn and tanning. (A third type of rays, ultraviolet C, are intercepted by the Earth’s protective ozone layer.)
UVA and UVB damage the DNA in skin cells, causing mutations. These mutations can build up over time and cause tumors to grow. The more UV exposure you have, the higher your risk, according to the Skin Cancer Foundation.
Basal cell carcinoma is the most common type of skin cancer in the United States, followed by squamous cell carcinoma. About 5.4 million of these cancers combined are diagnosed each year, and they cause between 2,000 and 8,000 deaths, according to the American Cancer Society.
Skin melanoma is both rarer and deadlier, affecting about 100,640 Americans this year and resulting in 8,290 deaths, according to the National Cancer Institute.
Sunscreens can protect you from these malignancies in two ways. Chemical sunscreens contain ingredients like avobenzone that absorb UV rays. Mineral sunscreens use zinc oxide or titanium dioxide to block or reflect the rays. In both cases, the sun’s radiation is unable to penetrate the skin and corrupt your DNA.
Here are 10 sunscreen myths you can’t afford to fall for:
Myth 1: As long as you don’t get sunburned, you’re safe.
Reality: You don’t have to get a sunburn to put your skin at risk. UV exposure compromises the DNA of unprotected skin — even if your skin appears normal to the naked eye — and the effects are cumulative, said Dr. Henry Lim, a photodermatologist at Henry Ford Health in Detroit who studies the sun’s effect on skin.
“Any time the skin is damaged by the sun, with or without a sunburn reaction, it suffers damage that it needs to repair,” Lim says. “If this subclinical damage occurs often enough for a long enough period of time, the skin’s ability to fully repair all of this DNA damage will be compromised.”
Myth 2: Your body needs vitamin D, and sunscreen will prevent you from getting it.
Reality: Just a little sun exposure is enough to produce all the vitamin D your body needs. A study of white people in the Boston area found that 5 to 10 minutes of sun exposure to the face, arms, and legs two to three times a week during the summer months was enough to produce adequate amounts of vitamin D.
Even if you apply sunscreen, you will still have minimal exposure to the sun, Lim said. “When we use sunscreen, we don’t apply enough,” he said. “That’s just human nature.”
Dr. Anne Chapas, a Manhattan dermatologist and clinical instructor at Mt. Sinai Medical Center, advises patients concerned about their vitamin D levels to protect their skin and seek out the nutrient in foods or take supplements.
“You need vitamin D to be healthy, but there are multiple ways to get it,” she said.
Myth 3: Chemicals in sunscreen can cause cancer.
Reality: The active ingredients in sunscreens sold in the United States are regulated by the Food and Drug Administration, which has determined that they are safe and effective. The National Academies adds that “sunscreen use is not linked to higher rates of any cancer.”
In fact, the opposite is true, Chapas said: “If you’re trying not to get cancer, then wear sunscreen.”
Myth 4: You don’t need to wear sunscreen when the UV index is low.
Reality: The UV index primarily measures UVB, which Lim calls “the sunburn spectrum.” Even though UVB is low, you still need to protect yourself from UVA.
“As long as there is light, there is enough UVA” to induce tanning, cause wrinkles and contribute to skin cancer risk, Lim said.
Chapas agrees. “Even on a cloudy day, about 80 percent of the sun’s rays get through and you can still get sun damage,” she said.
Myth 5: You don’t need sunscreen if you have dark skin.
Reality: People of all skin tones can be affected by sun damage and skin cancer. In fact, “skin cancer in patients with darker skin is often diagnosed at a later stage, when it is more difficult to treat,” said Dr. Seemal Desai, president of the American Academy of Dermatology.
Chapas added that because darker skin is likely to produce melanin in response to sun exposure, it may fade more easily than lighter skin.
Myth 6: Mineral-based sunscreens are safer than chemical sunscreens.
Reality: Both types are safe to use, but mineral sunscreens have fewer unknowns since they are not absorbed through the skin, Lim said.
Chapas said that’s one reason she prefers mineral sunscreens. She also likes their versatility, since they can be applied over makeup or moisturizer. “The problem is that some of these formulas have a white cast, so you have to find one that works with your skin tone,” she said.
Myth 7: You can protect yourself from the sun by creating a “base tan.”
Reality: A tan may offer some protection, but it’s less than the equivalent of SPF 5, Lim said. That’s not enough to make sunscreen useless.
Additionally, tanning is itself a sign of sun damage. “When our skin is exposed to UV rays, it stimulates melanin production to prevent more UV rays from penetrating the skin and damaging the underlying skin cells,” Chapas says. “A tan is not healthy. In fact, tanning is a sign that your body is trying to protect itself.”
Myth 8: Astaxanthin, an antioxidant, protects you from UV rays and acts as an “internal sunscreen.”
Reality: According to Lim, antioxidants reduce the biological damage caused by sun exposure in two ways. When UVA rays damage DNA, they do so by causing oxidative DNA damage, and antioxidants can help minimize this. Additionally, when visible light interacts with the skin, it can cause cells to produce a type of destructive molecule called reactive oxygen species. Antioxidants can help counteract this process as well.
It makes sense to include antioxidants in a sunscreen routine, but they can’t do the job on their own. “There’s no pill that’s as effective as sunscreen,” Chapas said.
If you’re looking to take an antioxidant to reduce sun damage, astaxanthin may not be the best choice, Lim and Chapas agree. Chapas’s recommended product is Heliocare.
Myth #9: Chemicals in sunscreen enter your bloodstream and build up over time.
Reality: There are no long-term studies on the blood of people who regularly use sunscreen, so there is no data to say whether this claim is true or false. However, the chemicals are excreted in urine, which is a sign that they do not persist in the body, Lim said.
People who are wary of chemical sunscreens can opt for mineral sunscreens, he said.
Myth 10: You can prevent sun damage by wearing a good hat.
Reality: A wide-brimmed hat will definitely protect you from the sun. This is especially true for people who are balding or have thinning hair, because “we don’t have effective sunscreen for areas where hair grows,” Chapas said.
However, a hat will only block UV rays coming from above. Without sunscreen, you’ll still be vulnerable to rays reflecting off water, sand, or urban surfaces like a sidewalk and hitting your skin from below. (This is also why you need sunscreen even if you’re in the shade.)
“We need to take multiple measures,” Lim said. “Each one of them helps, but it’s not as effective as putting all the measures together.”