Last week, Outside magazine published a piece about the potential perils of sunscreen. Titled “Is Sunscreen The New Margarine?”, it attacked the presumption that people should generally be wearing sunscreen since it might prevent us from getting enough Vitamin D.
This is a bold claim in our ozone-depleted times. Unfortunately, the article, written by Rowan Jacobsen, is based primarily off of a single, controversial Swedish study from 2016 that isn’t even about sunscreen, and unpublished research from a dermatologist at the University of Edinburgh. The article also fails to account for copious research that indicates, for the most part, that sunscreen does not prevent us from getting enough Vitamin D, and that wearing it has definite health and cosmetic upsides and virtually no downsides.
First things first. Vitamin D, which is not technically a vitamin but a steroid hormone, is essential for human bone health. Your body primarily synthesizes it through sun exposure, and deficiencies can have serious, long-term effects, such as depression, diabetes, and fibromyalgia.
Over the past 20 years, alarmists such as The Endocrine Society have stirred up controversy over what are the appropriate and necessary levels of vitamin D, saying that deficiency of the vitamin has reached pandemic levels. Meanwhile, skeptics — including the National Academy of Medicine — maintain that you may not need as much vitamin D as many doctors claim you do.
As the Outside article accurately states, the vitamin D supplements prescribed to many supposedly deficient patients are essentially useless, as multiple studies in recent years have found them ineffective at countering the side effects of vitamin D deficiency, like invasive cancer or cardiovascular issues.
If so many of us are in dire need of vitamin D, Outside argues, and vitamin D supplements aren’t doing the trick, then the issue must be something else — and that something else is sunscreen. To paint this portrait, he relies mostly on the aforementioned Swedish study,which was published in the Journal of Internal Medicine. The observational study assessed the mortality rates of women who avoided the sun versus women who embraced it; researchers found that women who avoided the sun had a higher chance of death than those who didn’t: “avoidance of sun exposure is a risk factor of a similar magnitude as smoking, in terms of life expectancy.”
But more concerning is what the study doesn’t discuss: its participants’ sunscreen habits. It’s not mentioned anywhere in the research, which is fine for the study, as its use wasn’t the researcher’s question, but more problematic for Outside, which makes that connection anyway; Jacobsen writes that “the idea [that] slavish application of SPF 50 might be as bad for you as Marlboro 100s.” Regardless of whether the original study is particularly well-grounded, it didn’t take sunscreen into account, and it is more than a little misleading to presumptively make that connection when the study doesn’t.
Ade Adamson, a dermatologist at the University of Texas at Austin, told me he doesn’t agree with the study’s assertion that avoiding sun exposure is as dangerous as smoking. “Another explanation for this Swedish study is that people that just go outside, they smoke less, they’re less depressed, they exercise more,” he told me.
Indeed, the study asked the participants about their smoking and exercise habits, finding that those who spend more time outdoors also smoke less, exercise more, and have a higher disposable income. While sun exposure is a significant contribution to vitamin D levels — and could be, as the study found, responsible for lower mortality — the number of confounding variables present within this research makes that difficult to tease out.
While sun exposure is shown to have an impact on vitamin D, normal sunscreen use probably isn’t responsible for deficiencies. This has been demonstrated over and over again: “No person, including those aged 70 years and over, developed any vitamin D levels outside the normal reference range,” reports one. Most of us, when we do wear sunscreen (and most people don’t: 43 percent of women and 18 percent of men report regularly wearing sunscreen on their face), don’t wear it correctly. We only apply it to our face, or we don’t apply enough, or we don’t reapply it as often as we’re supposed to. Numerous studies have found that this imperfect sunscreen use allows us to get an adequate amount of vitamin D.
The amount of sun exposure you actually need probably isn’t very much anyway. Depending on where you live, your age, and how dark your skin is, 5 to 15 minutes of sun exposure on your back, face, arms, or legs two to three times a week is usually enough for you to maintain recommended levels of vitamin D, according to the Cleveland Clinic.
While Outside’s analysis of the relation between sunscreen and vitamin D is specious at best, the article gets one thing incredibly right: we’ve been sold a bill of goods about the miracle-working of sunscreen that may not be as accurate, or widely applicable, as we have been led to believe.
“We do a lot of fear-mongering around sunscreen that may be unnecessary,” said Adamson. “People want a simple digestible message, and in this base, there’s more nuance.”
A recent analysis in the Journal of American Academy of Dermatology looked at previous research on the effect of sunscreen use on the development of various types of skin cancer. It found only four prospective studies examining this relationship, and none of them looked at people who didn’t already have an increased likelihood of skin cancer (for example, people with a history of sunburn or skin cancer, or redheads).
The cumulative findings of these four studies is that sunscreen helps prevent squamous cell carcinoma, a typically non-lethal form of skin cancer, but its effect on basal cell carcinoma, another common but usually not deadly form of skin cancer, and the potentially deadly melanoma, is less clear. The analysis emphasizes that this doesn’t mean sunscreen doesn’t protect against these cancers, but because the cancers take decades to develop, it’s very difficult to study them.
So if it’s not totally certain that sunscreen prevents most skin cancers, should you still wear it? This is where Outside and most professional and academic establishments differ. If sunscreen probably decreases your likelihood of skin cancer, and doesn’t impact your vitamin D levels, then yes, you should wear sunscreen, particularly if you’re going to be spending an extended portion of your day in the sun (this is particularly advisable on days with a high ultraviolet index, or in places with thinner ozone, like in Australia).
But such advice is not one-size-fits-all: it’s most likely not true for people of African descent. “Your risk of skin cancer is directly related to how much melanin you have in your skin … I don’t recommend sunscreen for darker patients for skin cancer prevention,” Adamson said. And while I struggle to protect my pasty white complexion with sunscreen while it wrinkles up like a sad raisin, this is less of an issue for darker-skinned people. According to Adamson, melanin “slows down photoaging,” although everyone eventually develops somewrinkles in old age, and sunscreen can help with that to some degree regardless of skin tone.
It’s easy and tempting to find shocking new scientific study results and report them out as if they’re going to change everything we know. But science is built on reproducibility — that is, that a study can be done repeatedly with similar results — and single studies should be taken for exactly what they are: usually little more than an early, intriguing finding that warrants more research.
So with that said: I’ll continue wearing sunscreen every day, since I have very light skin, a family history of skin cancer, and am concerned about aging. And for you? Unless you have a deep skin tone, you should probably stick with the stuff, and practice diligence on beach days to avoid cancer-causing burns.
And don’t worry about your vitamin D levels. In all likelihood, they’re fine.