Joe Rogan Experience #2516 - Rowan Jacobsen

1. JRJoe Rogan0:02

   Joe Rogan Podcast, check it out.

2. RJRowan Jacobsen0:04

   The Joe Rogan Experience.

3. JRJoe Rogan0:06

   Train by day, Joe Rogan Podcast by night. All day. [upbeat music]

4. RJRowan Jacobsen0:12

   Yep.

5. JRJoe Rogan0:13

   All right. Very nice to meet you, man.

6. RJRowan Jacobsen0:15

   You too. Thanks for having me.

7. JRJoe Rogan0:15

   Thank you. And thanks for doing this work, because you wanna talk about a subject that's confused so many people. Is the sun good for you? Is the sun killing you? Why does it give you vitamin D if it's bad for you? Why, why do people get skin cancer if it's good for you?

8. RJRowan Jacobsen0:30

   Yeah. It's, it's super complicated, and the messaging has not sort of admitted that, and that was, yeah, a big impetus for the book.

9. JRJoe Rogan0:37

   When ... What was your opinion of sun exposure before you started writing this?

10. RJRowan Jacobsen0:43

    So I had, you know, I had inherited the conventional wisdom from the institutions that it was really bad. At the same time, I'll admit that my instincts, um, were that maybe it wasn't as bad as they were leading me to believe, 'cause whenever I was in the sun I felt good. And I live in Vermont. At the ... By the time winter was reaching like month six, I felt bad, right?

11. JRJoe Rogan1:07

    Right.

12. RJRowan Jacobsen1:07

    So I was like, "There's more here than, uh, than we're being told."

13. JRJoe Rogan1:10

    Yeah. That's, that was my wife's opinion. She's like, "The sun can't be bad. It always feels good when you go out there." I'm like, "I don't know. It's a little more complicated than that," but that is a-

14. RJRowan Jacobsen1:20

    Yeah

15. JRJoe Rogan1:20

    ... the instinct. Like, it feels great when you're in the sun. Like, ah. It's like your body wants it.

16. RJRowan Jacobsen1:25

    Your body wants it. I mean, we, we now know that it literally triggers the release of opiates in the brain, sunlight. So yeah, your body wants it, and your body rewards you when you get it.

17. JRJoe Rogan1:35

    So what is the issue? Well, well, let's g- go back to the beginning. So you had this idea that sun exposure is probably giving people cancer, and sunscreen is good. You need to wear sunscreen. Stay out of the sun. So when you started going into the research, what made you shift your opinion?

18. RJRowan Jacobsen1:52

    So it really started for me like seven or eight years ago. Um, I was on this, like, science journalism fellowship. So I was just doing research, and some of those studies hit, the one about opiate release in the brain, uh, other studies showing that when light hits skin, um, cognition actually improves. Like, your metabolism cr- cranks up a little bit when it, when your body feels sunlight coming in. Um, and I thought, that's interesting. C- um, that's all good stuff. Then I came across a couple other studies that seemed to indicate that, uh, sunlight could lower blood pressure, which was really interesting. So then, you know, I still had the sense sunlight bad, right? So then I remember just, like, Googling, like, "So how much does sunlight, like, shorten your lifespan?" Um, and, like, the punchline is sunlight seems to extend your lifespan. So when I s- hit that, I was like, "Why are we not hearing this?" So that was the beginning.

19. JRJoe Rogan2:46

    And so then, so what is the problem? Like, what, what is the issue with sunlight? Like, when you think about s- skin cancer, what are the confounding factors that lead to skin cancer? Are we completely aware of that?

20. RJRowan Jacobsen3:00

    You know, it's more complicated than we thought. So sunlight does, uh, increase your risk of skin cancer. But it, depending on the type of skin cancer you're talking about, it's not necessarily a, like a linear relationship. So yes, in general, too much sun increases your risk of skin cancer, but yeah, the question is, what are the confounding factors? How important is skin cancer compared to these other things? If sunlight reduces your risk of other diseases, how does that weigh against the risk of skin cancer? Um, so it, it's not the type of thing that can, you know, be done in a 30-second PSA.

21. JRJoe Rogan3:37

    Right. So, so sc- sun cancer that does c- cause skin cancer ... Or excuse me, sun exposure that does cause skin cancer, what, what is causing it? Why is it happening?

22. RJRowan Jacobsen3:49

    So, um, ultraviolet light, which is the most energy intense part of the solar spectrum, um, when those photons of light hit your skin, they go inside, right? We, we absorb all wavelengths of light to a greater or lesser degree, and that super high energy ultraviolet light, if it hits a DNA molecule, it can mess up the DNA molecule, and then that can lead to mutations and skin cancer. Um, then it can also indirectly cause skin cancer, um, by creating, uh, what are called reactive oxygen species, which are free radicals basically. So it energizes these, um, atoms that start to steal electrons from other atoms and cause a little chain reaction, which is what a free radical is. Um, so ultraviolet light can increase your free radicals, and it can directly damage DNA. So that's why it can cause skin cancer. So it was basically that, learning that one fact back in, like, the '40s and '50s, um, that made scientists start to say, "Uh-oh, light, skin cancer, maybe we should think about how much sun we're getting."

23. JRJoe Rogan4:54

    But this wasn't, uh, universally accepted, right? There were some people that even back then thought that sun exposure was very healthy for you. Like, when did we figure out that sun causes the body to produce vitamin D?

24. RJRowan Jacobsen5:08

    Yeah, that was an important part, and it's a big part of the story, I think, because that was really back in the '20s that we figured that out. And then even a little earlier we realized that, um, sunlight could prevent rickets. So-

25. JRJoe Rogan5:19

    Rickets?

26. RJRowan Jacobsen5:20

    Yeah. So rickets is a, like, soft bone disease. Like, if you, you don't ha- get enough, um, calcium in your bones when you're a kid, when you're a baby, you get soft bones, you get rickets. Really bad disease. Um, and it was, in the Industrial Revolution, kids starting getting rickets, started getting rickets. Um, farm kids never got rickets. Then suddenly kids are working in factories, they are living in cities that are choked with coal, coal smog, they're living in tenement buildings, they're never seeing the sun, and they all start getting rickets la- late 1800s. Uh, and-

27. JRJoe Rogan5:52

    Is nutrition a factor in that?

28. RJRowan Jacobsen5:54

    Vitamin D. It was all vitamin D.

29. JRJoe Rogan5:55

    Ju- Oh.

30. RJRowan Jacobsen5:56

    At first they thought maybe it was vitamin A, um, but the, it turned out it was, that was how vitamin D was discovered Was, um, some doctors figured out that it could solve kid- rickets in kids, and then they figured out that if sun hits skin, that's how we made vitamin D. Then they figured out-

Episode duration: 2:00:46