Even in Arizona, this author says Americans should spend more time in the sun

Lots of Arizonans do everything we can to avoid being in the sun — we search for covered parking or try to walk on the shady side of the street. If we can’t find shade, we wear hats or long shirts and pants to avoid sun exposure. And absent all of that, lots of us make sure to apply sunscreen.

But Rowan Jacobsen says minimizing our sun exposure may be exposing us to other health risks, including missing out on some of the sun’s benefits.

Jacobsen is a science writer and author of the new book “In Defense of Sunlight: The Surprising Science of Sun Exposure.” In it, he argues there are both physical and mental health benefits of sunlight.

He joined The Show to talk more about it.

Full conversation

MARK BRODIE: Rowan, you’re basically making the argument that we just aren’t spending enough time in the sun. Is that about right?

ROWAN JACOBSEN: Well, depends who “we” are — who you are and where you are. But many of us, yes, don’t get enough time in the sun. In Arizona, the math is slightly different. But yes, Americans in general would probably benefit from getting a little bit more sun exposure.

MARK BRODIE: OK. And why is that? Because as you say, the conventional wisdom is to avoid being in the sun, try to find the shade, make sure you’re wearing a hat, sunscreen, all of that. So why is that maybe not entirely the case?

ROWAN JACOBSEN: Yeah. And so all of those recommendations were based on kind of the first thing we learned about sun exposure, which is that it can raise your risk of skin cancer, which is true. So, those recommendations went into place and got very well established in this effort to lower rates of skin cancer.

Since that time, since those discoveries were made 60-70 years ago, other areas of medicine have made all these discoveries about these benefits of sunlight that actually have nothing to do with skin cancer. So we know it can lower blood pressure, it can improve the immune system, it can extend longevity and reduce your rates of cardiovascular disease and certain other cancers.

So all that sort of has come later and hasn’t been incorporated into the recommendations yet. Part of the reason I wrote the book is because I thought it was time to consider the subject as a whole and maybe come up with new recommendations.

MARK BRODIE: So when you look at the costs and benefits, do the benefits of — as you reference, lowering risks of certain diseases, that kind of thing — do those outweigh the potential risks of skin cancer?

ROWAN JACOBSEN: I think they do in many circumstances, and there’s a couple of different factors involved in that equation. Skin cancer, it’s very common, but it’s generally not a deadly disease. It doesn’t kill that many people. It’s not one of the top 40 or 50 killers. Doesn’t mean that it doesn’t have impacts beyond mortality. There’s still a lot of cosmetic issues with it, and it’s no fun to get a little chunk of yourself cut out.

But in terms of moving the needle on mortality or on long-term disability, other diseases like cardiovascular disease and internal cancers are much bigger factors. And those are the ones that do seem to be improved by at least a little bit more sunlight.

MARK BRODIE: I can imagine right now any number of dermatologists screaming at the radio or at their computers if they’re listening on the radio. Have you gotten a lot of pushback on this?

ROWAN JACOBSEN: Well, to my surprise, dermatologists are some of the most interested in this subject, and I think we’re going to see some changes in dermatology in the future. But yeah, it’s going to take a little time for everyone to sort of get on the same page.

But understanding skin’s role in keeping us healthy is what dermatology is all about. And so they are going to be incorporating these new discoveries, this new science, and they’re the ones who are going to be leading the way in coming up with plans for how you can get the right amount of sun on your skin to maximize the benefits without having to really increase the risks.

And it looks like we don’t need to really raise our risk of skin cancers significantly in order to get the basic benefits of modest sun exposure. So I actually think dermatologists are going to be leading the way on this, although, as you imply, there might be some awkward conversations on the way there.

MARK BRODIE: Yeah. OK, so you mentioned the amount of time we might need to be in the sun. Do we have a sense of that yet? Like, do you need to be out just for a couple of minutes in sun exposure? Do you need to lay on the beach all day to get these benefits?

ROWAN JACOBSEN: Yeah, great question. And you definitely do not need to lay on the beach all day. In fact, more and more, it looks like almost all the problems with skin cancer are stemming from that sort of all-day at Cancun approach, right? Especially if you had pretty pale skin going into that vacation time, and then you’re on the beach all day, that’s when you’re going to get into trouble.

It looks like garden variety daily doses of sun exposure don’t significantly increase the risk of skin cancer for most people, but those are enough to reap the benefits. Like say, somewhere like Arizona this time of year, you’re going to get more sunlight than you know what to do with, so you don’t need to seek it.

But say like mid-winter in Arizona? Yeah, probably somebody with fair skin could benefit from, say, half an hour in the sun midday.

MARK BRODIE: You reference that the math in Phoenix might be a little different. I wonder if it’s such a good idea, or if it’s even necessary in the summer here when it’s already so hot and so sunny to spend additional time, or if, as you kind of alluded to, what we’re doing day-to-day is sufficient here?

ROWAN JACOBSEN: Yeah, I would expect that in summer, everybody is just sort of inadvertently getting what they want. Although, I grew up in Florida, and so I know from summers in Florida, it’s almost like reverse winter, where you’re in air conditioning all the time. So, you actually don’t see a lot of light in some of these very warm places in summer.

MARK BRODIE: And does it have to be direct sunlight? Like, if somebody is outside, let’s say they’re in the sunlight, it’s sunny out, but they’re in the shade under a tree, maybe dappled sunlight, do they still get the benefits? Or do you have to be in direct sunlight?

ROWAN JACOBSEN: That is a great question, also. And yes, I’m actually a big fan of the dappled sunlight and the shade of a tree, because the ultraviolet portion of sunlight is the one that people worry about in terms of skin cancer. It’s the highest energy part, but it’s blocked very nicely by shade or trees or things like that. You only need a little bit of that.

And some of the other benefits come from the other wavelengths, like the visible part of the spectrum and the infrared part of the spectrum. And those get bounced around. They bounce off of trees and other greenery, grass. So, if you’re in the shade of a tree in a park, you’re actually getting a lot of these beneficial rays that aren’t going to raise your risk of skin cancer — and just a smidge of the riskier stuff.

The other thing that could work well is early morning and evening light, because when the sun is really low in the sky, the more atmosphere the sunlight is coming through, the more that ultraviolet light is going to get filtered out. So, that morning light is really nice in terms of giving you some of the benefits, none of the risks, and also in terms of your circadian rhythms, it’s going to jump start your day, get your metabolism running a little bit earlier, so it can be good from a cardiovascular spectrum and from setting you up with the sun schedule so that you sleep better at night.

MARK BRODIE: Do we diminish the benefits of sunlight if we’re wearing sunscreen?

ROWAN JACOBSEN: We do to a certain extent, because the sunscreen is literally screening out 95-96% of that ultraviolet light, which is why it reduces your risk of skin cancer. But again, in an environment where you’ve got tons and tons of photons coming in, like Florida or Arizona, that sunscreen is going to work for you in the brighter times of the year.

And in fact, if sunscreen gets people outside more, then that is all to the benefit. So, I kind of think of sunscreen as a good aid in this process if it does get people outside more.

MARK BRODIE: All right. That is Rowan Jacobsen, a longtime science writer, author of the new book, “In Defense of Sunlight: The Surprising Science of Sun Exposure.” Rowan, thanks so much. I appreciate it.

ROWAN JACOBSEN: Thanks, Mark.

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