By Elizabeth K. Hale, MD and Julie K. Karen, MD
A recent article in Outside alleges that sun exposure guidelines are “unhealthy and unscientific… and quite possibly even racist.” Drs. Hale and Karen respond.
As dermatologists who not only preach, but also practice avid sun protection on a daily basis, we read Outside’s article “Is Sunscreen the New Margarine?” with tremendous interest and even some trepidation. While the article raises some interesting and legitimate questions about sun exposure and protection, it features unfounded and even preposterous claims that are at best misleading and at worst dangerous.
Sunscreen is bad.
Sunscreen is flawed for sure, but it is not intrinsically evil. The industry has made strides in correcting what was disproportionate UVB and UVA protection. And yes, oxybenzone is harmful to coral reefs and may cause hormonal imbalances so is understandably being banned for future use in the US. But those of us who treat skin cancer feel fervently about the need to promote a healthy lifestyle that doesn’t involve unprotected sun exposure and increasing one’s skin cancer risk.
Vitamin D doesn’t impart health benefits, the sun itself does.
“We have been epically misled,” the author claims of the correlation between low levels of vitamin D and the myriad health issues that accompany it, such as higher rates of cancer, diabetes, obesity, bone disease, heart attack, stroke, depression, and other diseases. Noting that vitamin D supplementation fails to affect the incidence of these maladies, he concludes that those with healthy vitamin D levels are not benefiting from the vitamin itself, but rather from exposure to “that big orange ball shining down from above,” aka the sun. Preposterous! Just because vitamin D supplementation has failed to eliminate the increased risk of the multiple aforementioned diseases doesn’t prove that sun exposure results in improved health. A far more intuitive conclusion is that a healthy lifestyle that accompanies relatively higher levels of vitamin D, including outdoor activity, exercise and accompanying mental health is why those who spend time outdoors have better health.
Sun exposure enhances nitric oxide levels.
In an effort to convince us of the benefits of sun exposure, the author cites Richard Weller’s research on nitric oxide (NO), an essential molecule whose primary function is vasodilation and thus, reduction in blood pressure. NO, a molecule with a short half-life (<1 sec) also enhances antioxidant activity. The article implies that the raising of NO levels and the associated decrease in blood pressure in those who are outside in the sun, is some beneficial result of unprotected sun exposure.
Well, it turns out that sun exposure is by no means the only or even most efficient way of elevating one’s NO levels. Not surprisingly, exercise also promotes NO production.
Here again, the positive health benefits enjoyed by “sun seekers” is quite possibly a reflection of their proclivity to exercise and live healthy lifestyles than to sun exposure itself.
Sun exposure lowers blood pressure.
In light of Weller’s research, the article wonders, “Could exposing skin to sunlight lower blood pressure?” Weller’s study involved 24 patients, each of whom showed immediate blood pressure reductions after one hour of exposure to light from a UV lamp. Even if sun exposure decreases blood pressure (if it’s through vasodilation, this is a short-term effect), these results do not prove that it will in turn decrease the incidence of death from heart disease and stroke. Medications can achieve far more significant reductions in blood pressure and still aren’t close to perfectly effective at reducing associated cardiovascular disease. Frequent moderate exercise is a far less dangerous way to lower blood pressure than unprotected sun exposure.
Recommending sun protection and avoidance is extreme.
The author compares dermatologists’ urging of patients to avoid the sun to an orthopedist recommending a ban on exercise. This is a false comparison. Orthopedic injuries are not deadly, whereas melanoma can be. And there is a huge difference between “enjoying the sun safely” and “step[ping] out into the light.”
The article in Outside seems deliberately inflammatory, subverting accepted ideas about sun exposure and sun protection for the sake of being controversial. While modern science is always shedding new light on accepted theories of health, and long-held conventional medical wisdom is frequently debunked by new discoveries, the evidence presented in this article does not rise to the necessary standard.
While we recommend being informed about the benefits of sunlight and the imperfection of sunscreen, the answer is not to discard what we know about the dangers of sun exposure and the importance of sun protection. It is well known that unprotected sun exposure leads to an increase in premature skin aging, skin hyperpigmentation, and increased risk of skin cancer, regardless of your skin type. Enjoy the Outside, but do it safely!
Elizabeth K. Hale, MD and Julie K. Karen, MD, are board-certified dermatologists (and sisters) who are in private practice together in New York City.