Q&A: Thinking about your sun exposure this summer? Journalist Rowan Jacobsen has answers.

As summer officially kicks off, the SLR’s Behind the Story host Amanda Ulrich chats with fellow journalist Rowan Jacobsen about his in-depth reporting on sunlight and sun exposure — and its many benefits you may not know about. Rowan gives his take on when you should wear sunscreen, how to write a narrative-driven science story, and whether or not moving to a sunny place may just be the key to longevity.

Rowan is a journalist and author who writes about science and nature for many publications, including most recently for Scientific American. He is a current media fellow with Nova Institute for Health. 

The following highlights, taken from their conversation, have been edited for brevity and clarity. 

The full version of this podcast episode is out now! You can listen to it on Spotify or Apple podcasts or wherever you get your podcasts.

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Amanda Ulrich: When did you start reporting on sunlight and sun exposure?

Rowan Jacobsen: It started back in 2018, when I was a Knight Science Journalism fellow at MIT. That’s one of those yearlong fellowships where you actually do not publish for a year, and your job is just to learn about whatever corner of science draws you, and try to learn it deep so that you can then turn around and report on it at a really high level.

And I ended up going deep on sunlight and health, because right around then, there were a few studies popping up showing that people who were naturally exposed to higher levels of light, or who lived in places that just naturally got more light, had lower rates of disease than people who lived in fairly sun-deprived places. And that was really curious to me because, you know, we always hear about the dark side of sunlight, how it raises the risk of skin cancer — which it does, but you don’t tend to hear that there’s also a positive side. So that got me wondering about balancing those risks and benefits. Then I did end up diving deep into the science.

With your reporting on sunscreen, can you talk about what you found there in terms of weighing sun exposure and then over-relying on sunscreen? Essentially, how did that change your practice of using sunscreen?

You know, it’s a fraught subject — and I don’t know if you saw the Environmental Working Group just released their annual review of sunscreens, and found that only a quarter of them passed their sort of safety standards. 

But my focus wasn’t really on sunscreen so much. It’s been more on, well, the sun has benefits as well as risks, so how do we balance that out? But sunscreen obviously does work into that equation at some level. I think sunscreens are going to get a little bit more scrutiny than they traditionally have been. But for me, where it falls is: Basically we’ve come to this extreme where the mainstream magazines and mainstream public health messaging says to use sunscreen 24 hours a day, 365 days a year, indoors or outdoors, winter or summer. Basically, even if you’re going to be working in your office all day, on a winter day: Put on sunscreen. And that’s clearly a very extreme position that is probably not beneficial to everyone.

And part of it is, I think that advice is being targeted to the fairest-skin people on Earth, who really do have to be extremely careful about sun exposure. So if there was a logic behind it, it’s that we need some very broad, simple, one-size-fits-all messaging; let’s make sure it works for this super, super susceptible population. And if everybody else just follows it, they’ll be fine too, because there are no benefits to sunlight. But now, of course, if it turns out there are some benefits of sunlight that people who are less susceptible to burning and skin cancer could be getting — and should be getting — then the messaging needs to get a little more complicated.

Your recent reporting talks about the handful of new clinical trials that are showing UV light, and these UV light devices, can really help people with autoimmune diseases like MS. Can you talk about those findings specifically, and what these UV light devices look like?

So MS is sometimes called the sunshine disease, because it is so closely associated with the amount of sun exposure. And this has been known for, like, 100 years. People have been tracking this and trying to figure out what it meant. But rates of MS are zero near the equator, and they just steadily rise as you go to higher latitudes in either direction, and they’re very closely associated with the amount of sun exposure.

So for 40 or 50 years, we’ve been using these ultraviolet lamps to treat psoriasis. And over time they figured out that they could use what’s called a narrow-band UVB lamp, that just shoots UV at around 311 nanometers wavelength, which is a wavelength that does not cause skin cancer, but does deliver some of these positive effects in terms of calming down the immune system. And that’s been very successful with psoriasis.

So that was used for a long time, but then people started noticing that sometimes people with psoriasis also have other autoimmune conditions going on systemically, not on their skin, and sometimes these UV treatments were actually improving their other conditions, too. So that got everyone to realize that the UV hitting skin, it wasn’t just a local effect on skin — it was actually changing the state of the immune system systemically.

Compiled by Amanda Ulrich. Photo of Kauai sunrise from Michael Janke/Creative Commons via Wikimedia.