Sunshine seems to make a strong case against daily sunscreen.
When we step outside on a clear day, the sun’s ultraviolet light triggers the body to produce endorphins that lower stress and boost mood. UV rays also tell our skin to make vitamin D. And when we look up at the morning sun, our bodies recognize daytime and adjust our sleep-wake cycle accordingly.
That might be enough to tempt some people to skip the sunscreen — indeed, dermatologists say their patients often worry they’ll miss out on these benefits.
“This is one of the biggest obstacles in people’s minds: the idea they shouldn’t use sunscreen for fear they won’t get vitamin D,” said Dr. Steven Q. Wang, the director of dermatologic oncology and dermatology at the Hoag Memorial Hospital Presbyterian in Newport Beach, Calif.
Recent surveys reflect this fear: In one poll of more than 1,000 adults in the United States, 11 percent of respondents said they thought wearing sunscreen was more harmful than direct sun exposure. In another, 15 percent said they thought sun exposure was the only way to get vitamin D.
But sunscreen also is our best weapon against skin cancer, which can be deadly. The sun’s UV rays damage the DNA in your skin cells, and that damage can add up over time. Every time DNA repairs itself, there’s a chance it develops a mutation that turns into cancer.
We asked nine experts whether you actually need to use sunscreen daily, and whether the sunlight’s potential benefits ever outweigh its risks. All said that there is no safe amount of unprotected sun exposure, and said you should be wearing broad-spectrum sunscreen with an SPF of 30 or more — every single day. Here’s what they want you to know about sunlight, sunscreen and your health.
Does sunscreen block the sun’s mood-boosting benefits?
Not necessarily, said Dr. Elisabeth Richard, an associate professor of dermatology at the Johns Hopkins University School of Medicine. Even with daily sunscreen, you can still enjoy a mood boost from the sun’s visible light, or the light we can see with our own eyes. Visible light doesn’t cause DNA damage like UV rays do, but it can increase serotonin, a chemical in the brain that helps regulate mood. This is why using a light box can ease symptoms of seasonal affective disorder, said Dr. Deborah Sarnoff, a professor of dermatology at New York University.
Dr. Richard said that if you’re concerned you’re missing out on endorphins from sun exposure, staying active can make up for it. And being outside generally, whether for a solo walk, a day of gardening or a picnic with friends, can boost your mood even beneath a generous layer of sunscreen.
“People are happier when they’re under the sunshine,” Dr. Wang said. “They’re more likely to lead an active lifestyle and enjoy social gatherings.”
Will sunscreen throw off my sleep cycle?
Your body’s internal clock relies on sunlight. When the sun goes down, your body releases the hormone melatonin, which promotes sleep. When the sun rises, it does the opposite to wake you.
But just seeing sunlight can make this happen, Dr. Richard said.
“We get this benefit through our eyes, not our skin,” she said. Even when you wear sunglasses — which protect your eyes from UV rays — you see enough light to get the circadian rhythm-promoting benefits of sunlight, she said.
Can I get enough vitamin D with daily sunscreen?
Our bodies need vitamin D to absorb calcium and stave off conditions like osteoporosis, said Dr. Robert Ashley, an internal medicine doctor at UCLA Health.
When we’re exposed to UV rays, our skin cells produce vitamin D. But you can also get vitamin D through your diet, Dr. Ashley said. Foods with vitamin D include fatty fish like salmon, tuna and mackerel, and fortified foods like milks and breakfast cereals contain it, too.
And even with daily sunscreen use, Dr. Sarnoff said, most people get enough UV exposure to make all the vitamin D they need. That’s because most people don’t apply enough sunscreen to fully shield the skin as often as needed.
“Even if you’re the best sunscreen user imaginable and you put on a thick layer and reapply it every two hours, there’s still a little bit getting through there,” said Dr. Sarnoff, who is also the president of the Skin Cancer Foundation.
“The risk of skin cancer is much more real than the risk of vitamin D deficiency,” Dr. Wang said.
He and other experts said that exposing your skin to UV damage just isn’t worth the risk.
“People want to hear they can get direct sun exposure for a little bit of time, maybe five minutes to a half-hour, and that’s enough to get the benefits,” Dr. Sarnoff said. “But the truth is, why even do that?”