Over more than two decades as a journalist and author, Rowan Jacobsen has left his cozy Calais home to report from war-torn Myanmar and to face rifle-toting drug-lord lackeys in the Amazon. But his latest book, In Defense of Sunlight: The Surprising Science of Sun Exposure, released on Tuesday, puts him in a different kind of risky position: at odds with decades of mainstream American health care advice.
The majority of Jacobsen’s previous books have focused on food, from the James Beard prize-winner A Geography of Oysters: The Connoisseur’s Guide to Oyster Eating in North America in 2007 to Wild Chocolate: Across the Americas in Search of Cacao’s Soul in 2024, which earned an award from the Society of American Travel Writers Foundation. He has also completed prestigious science-writing fellowships at MIT and the Nova Institute for Health and published articles in Scientific American and MIT Technology Review.
In Defense of Sunlight, Jacobsen’s 10th book, thoroughly investigates the arc of the sun’s reputation, from elixir of well-being to a lethal force from which we must hide like Dracula at dawn. In 1926, he reports, esteemed medical journal the Lancet lauded sunbathing as “one of Nature’s greatest aids to maintaining and acquiring proper health.” By the 1950s, the sun’s rays had become the object of “quasi-religious demonization,” Jacobsen writes.
Skin cancer is the reason, of course. While Jacobsen, 58, acknowledges that the sun’s ultraviolet rays can cause skin cancer, he argues that we have overstated the risks of sun exposure and thrown the baby out with the bathwater.
“More people die each year from choking than from melanoma, yet there’s no national smoothie campaign to try to get those numbers down, no celebrity doctors on the ‘Today’ show demonstrating how to safely eat a steak,” he writes.
Jacobsen asserts that our disproportionate fear of the sun, compounded by modern-day inside living, deprive us of a free, easily accessible health tonic. He outlines a growing body of research that demonstrates that, for most people, the risk of moderate sun exposure is far outweighed by its benefits, ranging from lower blood pressure to reduced chronic inflammation.
Even public health professionals in Australia, the country with the world’s highest rate of skin cancer, agree, Jacobsen writes. In 2023, a consortium including cancer specialists and dermatologists stated, “Completely avoiding sun exposure is not optimal for health.”
Jacobsen talked with Seven Days about how he landed on the subject of sun exposure, why the majority of Americans are still in the dark about the benefits of sunlight and how to survive a Vermont winter.
Your previous books have explored oysters, honeybees, apples, truffles and wild chocolate. You’ve also published articles about the intelligence of sperm whales and bioengineering the scent of extinct flowers. How do those two aspects of your career, food and science, fit together?
For a long time, I’ve worn these two hats, where my books were food-focused and most of my magazine writing was on science topics. But a lot of my food writing was actually science and nature writing in disguise. It was always about exploring our relationship with the natural world and our place in that natural world. [This book] was kind of a natural transition, because I think of light as the other nutrient besides food that we all have exposure to.
How did you land on sun and health as a book subject?
I was doing a science-writing fellowship at MIT when I started seeing studies indicating there were beneficial aspects of sun exposure. In Sweden, women who sought out sun had much better longevity than women who avoided the sun. Studies in the UK showed that ultraviolet light could reduce blood pressure and lower risk of all the cardiovascular diseases. There were also studies in mice showing that sun exposure could rev up the brain and improve mood. Others showed that when sun hit skin, it triggered a release of endorphins in the brain.
Most of what I’d heard about the sun had to do with skin cancer. I remember checking: I know sun’s bad for you, but how bad for you? That’s when I really went down the rabbit hole.
Let’s start with how good it is for us.
Sunlight seems to do a few different things. It reduces inflammation throughout the body, and, as we know, inflammation is at the root of many chronic diseases. As we age, our levels of chronic inflammation tend to go up, and regular sun exposure seems to dampen that down. It creates stress on the body and triggers our natural repair mechanisms. Like moderate exercise, a temporary natural stressor kicks the system into getting off its ass and dealing with it. You need that every day, just a little fire drill.
And sunlight is energy, which our body uses to make things like vitamin D, famously, and nitric oxide, which lowers blood pressure, among other things. [Note: Jacobsen presents evidence in his book that vitamin D in supplement form fails to provide the same health benefits.]
Sunlight also triggers all these signaling molecules that help the body stay on its regular diurnal cycles. You want your whole metabolism, your energy production to rev up in the morning for the day and then get quiet at night. Standard maintenance happens at night, activity during the day, and light hitting skin and eyes is how the body knows. You don’t want to have your maintenance guys taking out the trash and fixing the computers when you have to actually use the computers.
Why don’t we hear much about the upside of sun exposure?
It’s never been anyone’s job to look at the benefits of the sun and tell people about them. So much of science, the things that get heard, are the things that have some mechanism for getting the word out: a foundation or a nonprofit. Individual scientists don’t have much ability to get the word out.
There are all these well-funded entities whose task is to reduce rates of skin cancer. They’re doing their job by warning people about skin cancer. It’s not their job to think about how big the risk of skin cancer is in the greater scheme of things. When you do look at that, it’s kind of shocking to see how small skin cancer is in terms of mortality rates.
But very fair redheads do have a much, much higher risk of melanoma, so the recommendations are essentially written for them. The assumption was everyone else can just do the same thing, and it won’t hurt. Public health recommendations need to be super simple, or people get confused.
And Vermont does have among the highest melanoma rates by state.
Yes. If you look at the top 10, it includes Vermont, New Hampshire, Minnesota, Washington State — almost all northern states with high percentages of old white people. In Europe, the highest rates are all the Scandinavian countries. Mediterranean countries have lower rates, partly due to darker skin tone and partly due to more steady, regular sun exposure.
You make the point in the book that even as skin cancer rates have risen, the modern world has turned many people into moles (the subterranean animals, not the moles a dermatologist checks). That seems, ironically, to make us more susceptible to skin cancer.
Melanoma is more common in office workers than in outdoor workers. It’s much more common in people that have fair skin. It’s not associated with lifetime cumulative sun exposure, but it is associated with sunburns early in life.
The formula for melanoma is: Have really fair skin, work in an office where you never really see the sun, and then go to Jamaica on vacation and fry yourself for a week.
Your book title is a deliberate echo of Michael Pollan’s In Defense of Food, and you wrote a seven-word rule similar to his. Yours is: “Get sun. Not too much. Go outside.” Is that all there is to it?
It’s complicated, but all the experts agree: Don’t burn. Make it regular.
When you have regular, moderate amounts of exposure, your body knows to expect it and knows how to deal with it. Morning is great, not only because it gets your metabolism jump-started, but that morning light is very gentle and an alert for your body that the other stuff’s coming. And you want to get as much of your skin in the game as you can, so your face and hands aren’t the only ones doing the work of absorbing the rays. Run around naked in your yard. Vermonters are good at that.
Get as much skin in the game as you can… Run around naked.
Rowan Jacobsen
Midday, the woods are great. You’re not going to get too much UV. A mix of wavelengths is bouncing off the leaves and being filtered. That is basically how we evolved in the forest 2 million years ago.
But what the heck do we do in Vermont in the middle of winter?
Oh man, I wish I had an easy fucking answer. I try to ski or skate every day. It’s a challenge. Go on vacation to a place with more light if you can, but don’t get burned. It doesn’t mean lying on a beach. Just somewhere where you can be in shorts and a T-shirt helps a lot.
The other thing is augmenting your UV exposure with devices. Tanning beds are bad news, but there are new devices coming on the market that are approved specifically for giving you safe shots of UV. One is designed to be the perfect wavelength to make vitamin D, and you just do it for 60 seconds. But the sun is a full-spectrum medicine; it’s like the whole food. The light devices are maybe a protein shake. ➆
This interview was edited for clarity and length.
The original print version of this article was headlined “Let the Sunshine In | In Defense of Sunlight, Calais author Rowan Jacobsen builds a case for the health benefits of the sun”
This article appears in June 17 • 2026.
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