Is Sun Protection Bad for You?

For years, we’ve been told to stay out of the sun

and use sunscreen. Those guidelines may not only be unnecessary—they also could be

harming our overall health.

These are dark days for supplements. Although they are a $30-billion-plus market in the United States alone, some of them, such as vitamin A, selenium, glucosamine, chondroitin, and fish oil, have now flopped in study after study.

If there was one supplement that seemed sure to survive the rigorous tests, it was vitamin D. People with low levels of vitamin D in their blood have significantly higher rates of virtually every disease you can think of: cancer, diabetes, obesity, osteoporosis, heart attack, stroke, depression, cognitive impairment, autoimmune conditions, and more. Vitamin D deficiency is even suspected of being a factor in severe COVID-19 cases.

Health experts believe that most of us aren’t getting enough of this essential vitamin. Vitamin D is a hormone manufactured by the skin with the help of sunlight. It’s difficult to obtain in sufficient quantities through diet. When our ancestors lived outdoors in tropical regions and ran around half naked, this wasn’t a problem.

They produced all the vitamin D they needed from the sun.

But today, 90 percent of us spend about 22 hours indoors every day, according to EPA research. And when we do go outside, we’ve been taught to slather on sunscreen to protect ourselves from dangerous UV rays, which can cause skin cancer. Sunscreen can reduce our natural production of vitamin D, so we’ve been told to compensate with vitamin D pills.

Yet vitamin D supplementation has failed in clinical trials. One of the largest trials ever conducted—in which 25,871 participants received high doses for five years—found no impact on cancer, heart disease, or stroke.

How did we get it so wrong? How could people with low vitamin D levels clearly suffer higher rates of so many diseases and yet not be helped by supplementation?

A rogue band of researchers argue that what made the people with high vitamin D levels so healthy was not the vitamin itself. That was just a

marker. Their vitamin D levels were high because they were getting plenty of exposure to the thing that was really responsible for their good health— that big orange ball shining down from above.

One of these researchers is a mildmannered dermatologist at the University of Edinburgh named Richard Weller, MD. For years, Dr. Weller swallowed the line about the destructive nature of the sun’s rays. “I’m not by nature a rebel,” he insists. “I was always the good boy that toed the line at school. This pathway is one which came from following the data rather than a desire to overturn apple carts.”

About ten years ago, Dr. Weller was researching nitric oxide, a molecule produced in the body that dilates blood vessels and lowers blood pressure. He discovered a previously unknown biological mechanism by which the skin uses sunlight to make nitric oxide.

It was already suspected that rates of high blood pressure, heart disease, stroke, and overall mortality all rise the farther you get from the sunny equator, and they all rise in the darker months. Dr. Weller put two and two together and had what he calls his eureka moment: Could exposing skin to sunlight lower blood pressure?

"WHEN I DIAGNOSE A BASAL CELL SKIN CANCER, I SAY CONGRATULATIONS."

Sure enough, when he exposed volunteers to the equivalent of 30 minutes of summer sunlight without sunscreen, their nitric oxide levels went up and their blood pressure went down. Because of its connection to heart disease and strokes, high blood pressure is a leading cause of death in the world, and the reduction was of a magnitude large enough to prevent millions of deaths on a global level.

Wouldn’t all those rays also raise rates of skin cancer? Yes, but skin cancer kills surprisingly few people: fewer than three per 100,000 in the United States each year. For every person who dies of skin cancer, about 80 die from cardiovascular diseases.

People don’t realize this because several different diseases are lumped together under the term skin cancer.

The most common by far are basal cell carcinomas and squamous cell carcinomas, which are almost never fatal. In fact, says Dr. Weller, “When I diagnose a basal cell skin cancer in a patient, the first thing I say is congratulations, because you’re walking out of my office with a longer life expectancy than when you walked in.” That’s probably because people who get carcinomas, which are strongly linked to sun exposure, tend to be healthy types who are outside getting plenty of exercise and sunlight.

Melanoma, the deadly type of skin cancer, is much rarer, accounting for only 1 to 3 percent of new skin cancers. And perplexingly, outdoor workers report lower rates of melanoma than indoor workers. “The risk factor for melanoma appears to be intermittent sunshine and sunburn, especially when you’re young,” says Dr. Weller. “But there’s evidence that long-term sun exposure associates with less melanoma.”

These are pretty radical words in the established dermatological community. “We do know that melanoma is deadly,” says Yale University’s David Leffell, MD, one of the leading dermatologists in the country, “and we know that the vast majority of cases are due to sun exposure. So certainly people need to be cautious.”

Still, Dr. Weller kept finding evidence that didn’t fit the official stayout-of-the-sun story. Some of the best came from Pelle Lindqvist, PHD, a senior research fellow in obstetrics and gynecology at Sweden’s Karolinska

Institute. Lindqvist tracked the sunbathing habits of nearly 30,000 women in Sweden over 20 years. Originally, he was studying blood clots, which he found occurred less frequently in women who spent more time in the sun—and less frequently during the summer.

Lindqvist also looked at type 2 diabetes. Sure enough, the sun worshippers had much lower rates. Melanoma? True, those with more sun exposure had a higher risk of it—but they were eight times less likely to die from it.

So Lindqvist decided to look at overall mortality rates, and the results were shocking. Over the 20 years of the study, sun avoiders were twice as likely to die as ardent sunbathers.

There are not many daily lifestyle choices that double your risk of dying. In a 2016 study published in the Journal of Internal Medicine, Lindqvist’s team put it in perspective: “Avoidance of sun exposure is a risk factor of a similar magnitude as smoking, in terms of life expectancy.”

For Dr. Weller’s largest study, published in February 2020, his team tracked the blood pressure of 340,000 people in 2,000 spots around the United States, adjusting for variables such as age and skin type. The results clearly showed that the reason people in sunnier climes have lower blood pressure is as simple as light hitting skin.

When I spoke with Dr. Weller, I made the mistake of characterizing this notion as counterintuitive. “It’s entirely intuitive,” he responded.

“Homo sapiens have been around for 200,000 years. Until the Industrial Revolution, we lived outside. How did we get through the Neolithic era without sunscreen? Actually, perfectly well. What’s counterintuitive is that dermatologists run around saying, ‘Don’t go outside; you might die.’”

When you spend much of your day treating patients with terrible melanomas, it’s natural to focus on preventing them. But the big picture reveals the limitations of that

thinking—and keeps getting more interesting. Vitamin D now looks like the tip of the solar iceberg. Sunlight triggers the release of a number of other important chemicals in the body, such as serotonin and endorphins. It reduces the risk of prostate, breast, colorectal, and pancreatic cancers. It improves circadian rhythms. It reduces inflammation and dampens autoimmune responses. It improves virtually every mental condition you can think of. And it’s free.

These seem like benefits everyone should be able to take advantage of. But not all people process sunlight the same way. People with darker skin need higher doses of sun to get its health bonuses. But they, too, are getting the opposite message.

Every year, Dr. Weller spends time working in a skin hospital in Addis Ababa, Ethiopia. Not only is Addis Ababa near the equator, but it also sits 7,500 feet above sea level, so it receives massive UV radiation. Despite that, says Dr. Weller, “I have not seen a skin cancer. Yet people of African descent in Britain and America are told to avoid the sun.”

All early humans evolved outdoors beneath a tropical sun. Like air, water, and food, sunlight was one of our key inputs. Humans also evolved a way to protect our skin from receiving too much radiation—melanin, a natural sunscreen. Our dark-skinned African ancestors produced so much melanin that they never had to worry about the sun.

People of color rarely get melanoma. In the United States, the rate is 26 per 100,000 in Caucasians, 5 per 100,000 in Hispanics, and 1 per 100,000 in African Americans. On the rare occasion when African Americans do get melanoma, it’s particularly lethal—but it’s usually a kind that occurs on the palms, on the soles of the feet, or under the nails and is not caused by sun exposure.

At the same time, African Americans suffer high rates of diabetes, heart disease, stroke, internal cancers, and other diseases that seem to improve in the presence of sunlight, of which they may well not be getting enough. Because of their genetically higher levels of melanin, they require more sun exposure to produce compounds such as vitamin D, and they are less able to store that vitamin for shorter and cloudier days. They have much to gain from the sun and less to fear.

Dr. Leffell puts the differences this way: “While it is true that people with olive skin are at less risk, we do see an increasing number of people with that type of skin getting skin cancer. But skin cancer ... is rare in African Americans ... and although they represent a spectrum of pigmentation, [they] are not at as much risk.”

And yet they and other people of color are getting a very different story, misled into believing in aggressive

sun protection. On its website, the American Academy of Dermatology “recommends that everyone, regardless of skin tone, protect themselves from the sun’s harmful ultraviolet rays by seeking shade, wearing protective clothing, and using a broad-spectrum water-resistant sunscreen with an of 30 or higher.”

Dr. Weller finds that exasperating. “The cosmetic industry is now trying to push sunscreen at dark-skinned people,” he says. “This is a marketing ploy.”

Many experts in the rest of the world have already come around to the benefits of sunlight. Sunny Australia changed its tune back in 2005. When the UV index is below 3 (which is true for most of the continental United States in the winter), Australia’s official advice states: “Sun protection isn’t recommended unless you are outdoors for extended periods or near reflective surfaces, like snow. To support vitamin D production, spend some time outdoors in the middle of the day with some skin uncovered.”

New Zealand signed on to similar recommendations, and the British Association of Dermatologists went even further: “Enjoying the sun safely, while taking care not to burn, can help to provide the benefits of vitamin D without unduly raising the risk of skin cancer.”

Dr. Leffell recommends a “sensible” approach. “I have always advised my patients that they don’t need to crawl under a rock but should use common sense and be conscious of cumulative sun exposure and sunburns in particular,” he told me.

This does not mean cultivating a burnished tan. All the experts agree that sunburns—especially those suffered during childhood and adolescence—are particularly bad.

Ultimately, it’s your call. Each person’s needs vary so much with season, latitude, skin color, personal history, philosophy, and so much else that it’s impossible to provide a onesize-fits-all recommendation. As for me, I’ve made my choice. A world of healthy outdoor adventure beckons— if not half naked, then reasonably close. Starting today, I’m stepping into the light.

Outsideonline.com (January 10, 2019), copyright © 2019 by rowan Jacobsen.