From SPF to skin color, sunscreen’s effectiveness is complicated

0:01I'm Aisha Roscoe, and this is a Sunday Story from Up First. It's summer's last hurrah. Summer isn't over yet. So in these final days of summer, we've got great ideas. Summer may be winding down, but we still have a few last hurrahs to enjoy, like this long Labor Day weekend. And as you're packing up for the beach or a hike, don't forget the sunscreen. This mainstay of skincare is in the spotlight right now as questions swirl about changing ingredients, misleading sun protection factors, and longstanding public health advice. This week on The Sunday Story, a simple lotion that turns out to be anything but.

0:47Stay with us. This message comes from Satva. Big days require deep, restorative sleep the night before. The kind of sleep Sattva mattresses are designed for. And now save up to$625 on$1 ,000 or more at sattva.com slash NPR. Support for this podcast and the following message come from Dataiku. AI agents are transforming how enterprises work. The problem is many operate in secret. The right people rarely know what their agents are doing, if they're doing it right or that they even exist at all. Dataiku gives companies one place to see, control, and measure every agent across the entire business.

1:31Visit dataiku.com slash NPR. That's D-A-T-A-I-K-U dot com slash NPR. This message comes from NPR sponsor Charles Schwab with its original podcast on investing. Each week, you'll get thoughtful, in-depth analysis of both the stock and the bond markets. Listen today and subscribe at schwab.com slash oninvesting or wherever you get your podcasts. We're back with a Sunday story and an episode about the changing world of sunscreen. Joining me is Justine Paradis of New Hampshire Public Radio. She recently reported an episode on sunscreen for Outside In, a show where curiosity and the natural world collide.

2:17Justine, welcome to The Sunday Story. I'm thrilled to be here. Thanks for having me. So, Justine, what I know about sunscreen is, I imagine, what most people know, and it's this message that's been pounded into us since childhood, and that's just like, just wear it. Just wear sunscreen, because you've got to be protected from the sun. Right. It's the mantra, just slather it on. But, you know, sunscreen, this reporting has shown me that it's actually this really impressive product. It's kind of this advanced, very technical material. Now, when I think of sunscreen, I don't think technical. So that is interesting.

2:57Tell me more. Well, let's just break down what we look for in a sunscreen. Like, Aisha, what do you look for in a sunscreen for yourself? I don't want to get letters about this, but I'm going to be honest because this is a safe space, I hope. I don't really think about it that much. If I'm going to the beach or something, I do get sunscreen for me and the kids. And I just look at, you know, what's on the shelf and it's cheap and it's, you know, say it's sunscreen. That's all I look for. I don't want it greasy. I don't want it to show. Uh-uh. No, no, you don't. And you want it to last a while. Maybe even you want it to be water resistant.

3:33There are all these assumptions built in. And the biggest one is probably you want it to protect from sunburn and ultimately from cancer, right? I mean, that's the main thing. I don't want the cancer. I don't want the cancer or the sunburn. Definitely don't want the cancer. Yes. I know. And on top of that, you also want it to be pretty cheap. And I learned that these can be competing things on a chemistry level to be non-toxic and not oily and water resistant and be protective. Like this is a lot to ask from a lotion that you also want to look invisible. Yeah, it turns out it's super high tech.

4:09It's like someone said, hey, make me a cake that's vegan and nut free and dairy free. And it still works somehow. And it's great. This is Anna Wang. She is an associate professor of chemistry at the University of New South Wales in Sydney, Australia. And she calls herself a soft matter scientist. She told me this means she likes dealing with everything squishy, which I really love. I really appreciate it as that high tech material. and as a chemist and physicist, it gives you so much to work with from both those angles. Well, you know, I'm curious, what is the origin story of modern sunscreen?

4:46So the first commercial product for sunscreen was developed just after World War II. During the war, airmen were supplied with this product called Red Veterinary Petroleum or Red Vet Pet. It was this dark, thick jelly. And after the war, one of those airmen, who was a pharmacist, adapted the product into what eventually became Coppertone. Coppertone is taking the wraps off summer. Now, Coppertone is this iconic suntan cream that was immortalized in mid-20th century billboard and TV jingles, like ads showing a child with that gorgeous tan line and no burn.

5:28So that's a commercial from 1978. I mean, they used to have real jingles back then. We've been deprived. But I would think not only do we not have jingles like that now, I would think that a lot else has changed since then, right? Oh, definitely. I mean, Coppertone was originally marketed as a sun tan cream, so big emphasis on the tan. But over the years, the idea of sunscreen has morphed into more of a product to protect from the sun. And on that note, there is actually big news in sunscreen in the United States. Breaking sunscreen news? What is the breaking news on sunscreen? A new sunscreen ingredient.

6:09The Food and Drug Administration approved the chemical compound bemotrizinol in sunscreen sold in the U.S. It's a big deal. The first new active sunscreen ingredient has been approved in the United States in more than 25 years. It's called bemotrizinol or B-E-M-T. Bemotrizinol. Bemotrizinol. Bemotrizinol. B-E-M-T or bemotrizinol. And this has been decades in the making. Okay. Is it bimetrizinol or bimetrizinol? What is it? Honestly, I've heard it many different ways. I'm going with bimetrizinol, but... Okay. Okay. So bimetrizinol. And so how is that different from what is already available here in the U.S.?

6:52Yeah, in a few ways. So the way sunscreen works is that one way or another, it basically absorbs the light from the sun, those UV rays, which are harmful and can damage our DNA. BemaTrizinol has broader UV protection than what's currently on the market in the U.S. It also lasts longer, and it's a bigger molecule, so it doesn't absorb into the skin as easily as other molecules. And it's been available for decades in Europe, parts of Asia, Australia. It's better. It's advanced. This is Adewole Adamson. He goes by Ade. He is a dermatologist and associate professor in internal medicine at the Dell Medical School at the University of Texas, Austin.

7:32This is why, you know, you go online and you have influencers talking about sunscreens from other parts of the world. They all have this stuff. And so this is now our opportunity to be able to catch up with the rest of the world as it comes to, you know, modern sunscreens. Well, I guess I didn't realize we were behind the rest of the world when it comes to sunscreens. I think there was a thought that maybe we were on par with the rest of the world because we have those mineral sunscreens, right? Like, what about those? Totally. So in mineral sunscreen, the UV filters are zinc oxide and titanium oxide.

8:08And the perennial issue with them is the white paint effect. Some are better than others on this point, but as Aday put it, bematrizenol could be described as more, quote, cosmetically elegant. Okay. People want to protect themselves from the sun, but they don't want to look like a ghost. So if bimitrizinol is so much better and it's available in Europe and other parts of Asia, why did it take so long to be available here in the United States? That's a good question. It is confusing. Since it's intended to prevent skin cancer, the U.S. regulates sunscreen exclusively as an over-the-counter drug.

8:46That is different from how it's regulated in many other regions, including the EU, where sunscreen is regulated as a cosmetic. And what this means is we have an extremely high bar here. I spoke with Alexa Friedman, senior scientist with a consumer watchdog called the Environmental Working Group, or EWG. This is a group which has also been lobbying the FDA to consider more sunscreen ingredients. So I asked her. This sounds like, based on the U.S.'s higher standards, that sounds like we would have better sunscreens. It does. The issue is that in the United States, because of this lengthy process, we haven't had access to the same filters that are in international markets.

9:31So when Alexa says lengthy process, bemotrizinol was first proposed to the FDA in 2005. So if it gets to the market this fall, which is what's expected, that means it took more than 20 years. That's a long time. And I would imagine that is tough from a business standpoint. The sunscreen market's been sort of stuck. So for more than one reason, innovation in the sunscreen market has been challenging. But so far, at least, it's a bipartisan issue. It's a priority listed in the Make America Healthy Again, or MAHA, strategy report, and also elevated by Representative Alexandria Ocasio-Cortez. Like here she is in a social media video from 2023.

10:13U.S. sunscreens are far behind the rest of the world. I was in South Korea earlier this year, and it is so clear how far advanced the rest of the world is on sunscreen. And we deserve better here. There was another attempt to change the situation a few years ago, but at least for Bema Tries and all, things didn't change much until 2020 when Congress passed the CARES Act. Do you remember that? I've tried to block a lot of that out of my head, but I think, yes, this was the big coronavirus relief package, and people got those COVID relief checks. Yeah, I remember that too. But also, the CARES Act changed the way many over-the-counter drugs are regulated in the United States, including sunscreens.

10:56It basically helped streamline the application process. And now Bema Trizinol is finally about to hit the U.S. market. And it is a win. And it is an achievement for public health that we have this new filter. But at the end of the day, the U.S. still lags behind other countries like the EU when it comes to options. When we come back, another aspect of sunscreen in public health. The conversation on skin color and SPF. It was all white people in the Australian study. We'll be right back.

11:28Support for this podcast and the following message come from Dataiku. AI agents are transforming how enterprises work. The problem is many operate in secret. The right people rarely know what their agents are doing, if they're doing it right, or that they even exist at all. Dataiku gives companies one place to see, control, and measure every agent across the entire business. Visit dataiku.com slash NPR. That's D-A-T-A-I-K-U dot com slash NPR. This message comes from NPR sponsor Charles Schwab with its original podcast, On Investing. It's hosted by Lizanne Saunders, Schwab's chief investment strategist, and Colin Martin, head of fixed income research and strategy for the Schwab Center for Financial Research.

12:15Each week, Lizanne, Colin, and their guests analyze economic developments and bring context to conversations around stocks, fixed income, the economy, and more. Download the latest episode and subscribe at schwab.com slash oninvesting or wherever you get your podcasts. We're back with the Sunday story. I'm with Justine Paradis of New Hampshire Public Radio. She recently reported a deep dive on sunscreen. Ayesha, remember how earlier I said that sunscreen may seem ordinary, but it's actually kind of high tech and awesome? Yes, I remember that. Well, it's also imperfect. And to explain this, let's look at one of the most basic pieces of information on the bottle, SPF.

13:00Do you know what SPF stands for? I do not. I'll be honest about that as well. Something about the sun, I would think. Absolutely. Yeah, it stands for sun protection factor. So if you got an SPF of 30, in theory, it's saying that it offers you 30 times the amount of time until you get a sunburn as opposed to if you were wearing nothing. Does that make sense? That does make sense. I did not think it meant that. I thought it meant like the amount of rays blocked from the sun or something about the UV rays. But this also makes sense. It's confusing, but SPF is a super imperfect measurement. And to explain why, let's journey to the shores of Australia, fall 2025, where an Australian consumer watchdog group called Choice decided to test the SPF claims of sunscreen in the country.

13:5420 widely available products from brands like Neutrogena, La Roche-Posay, Cancer Council, Banana Boat. And 16 of those 20 products fell short of what they advertised. 16 out of 20? I mean, that sounds like a lot of misinformation. These were all sunscreens advertised to be SPF 50 or above, but they came in all over the place, like in the 40s, 30s, 20s and lower. Like one even tested at an SPF of 4. 4? Like, how could that happen? Like, that's not even close to what they advertise. eyes. I know. And I think that there are a few reasons that might have contributed. One of them is how SPF is tested in the first place.

14:39So the SPF of a sunscreen is determined by the in vivo test. So that's on human skin in a lab. They put sunscreen on one part of someone's body and no sunscreen on another. They expose both parts to UV radiation, and then they see how long it takes their skin to burn. And then they roughly measure redness. So it's a very subjective measure. This again is Alexa Friedman from EWG, a consumer watchdog. We know from, you know, various different studies and reports that there's like this issue of inconsistent testing, even the same formulation. So you could measure an SPF 50 at one lab and an SPF 30 at another.

15:19That's really surprising. You'd think it would be a consistent measurement. I know, yeah, the discrepancies are notable. Anna Wang, the soft matter squishy scientist, said there is an alternative SPF international standards test, which uses plastic instead of skin to evaluate sunscreen. But she says this isn't necessarily a more accurate method because... Skin is actually a really tricky material to try and emulate. It's like see-through to some wavelengths and not to other wavelengths. It's a mixture of like proteins and lipids. But there's also water inside and it's also rough and it has hairs.

15:55And the fact that it absorbs some of the ingredients that is not going to be emulated by pieces of plastic. Even though the discrepancies in SPF may seem dramatic, the fact is that the difference between an SPF 30, for instance, and an SPF 50 really isn't that much. Like without getting too much into the math, it's the difference between blocking 97 % of the sun's UVB rays versus 98%. And the reality is sunscreen is really just a thin film on your skin and it gets rubbed off. So whether it's an SPF 50 or an SPF 30, either way, it's typically not going to last more than a couple hours. I'm also going to compromise the sunscreen in that time by sweating, by moving around, by being in the wind, by being on sand.

16:37It's much better just to reapply. And one thing that almost any skincare pro will tell you is that no one actually ever uses enough sunscreen and you should reapply every couple hours anyway. That definitely sounds like a PSA to me. That's information I can use because growing up, you know, and even now, I mean, usually we put on that sunscreen once at the beach and we don't put it on no more. You know, I relate to that. You just spend the whole day out there. But it makes sense. And it is important because it's protecting us from skin cancer. Yeah, it does. But the way we know that is also an interesting story.

17:19It turns out the strongest evidence comes basically from a longitudinal study, one done over a number of years. And really, there's only been one fully powered, randomized trial looking at sunscreen as an exposure and skin cancer as an outcome. This is David Whiteman, a medical epidemiologist at QIMR Berghofer Medical Research Institute in Brisbane, Australia. That was done in a little town north of Brisbane here, a little sugarcane town called Nambour. It's called the Nambour Trial, the kind of research that takes a huge amount of resources and people and money and time. It started in the 1990s, and the investigator there, Adele Green, recruited more than 1 ,600 people in the town to participate.

18:01And then they were randomly assigned to one half were given free sunscreen and very strict instructions how to use it and constant badgering to get them to use it. The other half of the town were not given sunscreen. They were told they can use sunscreen if they wish to. Just do what you normally do. Both groups got free skin checks for up to a decade, checking out every little spot, looking for three types of cancers. They had teams of dermatologists pouring over the town. For one common type of skin cancer, basal cell carcinoma, they found the strict sunscreen use and skin checks didn't make a difference.

18:39For another, squamous cell carcinoma, it did. That rate dropped by almost 40%. But then there's melanoma, the rarer but scarier, more aggressive kind. That's the kind that kills people, right? Right, it's the deadliest one. But because melanoma is rarer, they didn't necessarily expect to see a significant difference with sunscreen and skin checks. But they did. Which was interesting and surprising. So sunscreen use did reduce melanoma? Yes. This isn't the only evidence to support this conclusion, but it is the only evidence at this level, which David described as, quote, the gold standard in clinical medicine.

19:23And it's probably the only evidence of that level that we're ever going to get, because it's unlikely that anyone in the future will ever be able to repeat a study like that. So love it or loathe it, that's the evidence that we have. And the entire kind of foundation upon which we promote sunscreen for prevention of melanoma rests on that single study. This again is dermatologist Adai Adamson. And Adai pointed out that as solid as this study is, it's not perfect. It was all white people in the Australian study, essentially. Well, all but four out of more than 1 ,600 participants. Okay, well, what does this mean for people of color?

20:08If the advice for white people is wear sunscreen every day, is that true for people of color too? Should black people wear sunscreen? Well, this is the question. First of all, my sources told me there's just not enough research on people of color, sunscreen, and UV exposure, period. But here's what we know. Skin cancer is a serious risk for people with lighter skin, people of Northern European descent, typically. But for Black people, the risk is way, way lower. Now, right up top, I do want to acknowledge here that people of color or even Black people, these terms are too broad. Obviously, skin tone varies widely within these descriptions, and I'll talk more about that in a minute.

20:53But in the United States, government data shows that melanoma is in the ballpark of 30 times more prevalent in white people than in black people. Death from any cancer, all of it's terrible, all of it's bad. I'm not saying let people just die, okay? But if you think about the problems, the things to think about as a black person that you could potentially die from or that is dangerous, skin cancer is the bottom of the list. Black people do get melanoma, and when they do, it's proportionally deadlier. But usually it occurs in places typically not exposed to the sun, like the palms of the hand or the soles of the feet.

21:31Famously, Bob Marley died from a melanoma under his toenail. So UV radiation may not be a major risk factor for melanoma in skin of color. So for folks with skin of color, there's actually no data to support the use of sunscreen for cancer prevention. That just hasn't been shown. Both epidemiologist David Whiteman and Adele Green, the investigator behind the Nambor trial, they agreed. The results of the Nambor trial can't necessarily be extrapolated to people of color. Not only that, but there is what David called very good data about the protective effects of melanin. Like he pointed to this study out of England where researchers simulated solar radiation on a variety of skin types to measure how melanin protected against DNA damage in the skin.

22:21And in this study, they found that compared to fair European origin skin types, the melanin content of the darkest skin tone demonstrated 60 times the protection against DNA damage in one of the deeper layers of skin. And the melanin pigment just absorbs. It's like a shield of armor above the DNA, absorbs that ultraviolet radiation. And so there's almost no DNA damage when you give skin of color quite high levels of UV. Certainly that would, in a European ancestry person, would cause unbelievable DNA damage. So back to that public health advice offered by major groups like the CDC, the American Cancer Society, the American Academy of Dermatology.

23:06They all say some version of everyone needs to wear sunscreen every day. And that message? I think it is deeply flawed. But I understand why certain authorities and officials like to just give blanket recommendations because it's easier. Now, Ade's opinion is that blanket recommendations are not supported by evidence, and that perhaps public health authorities should offer different, specific advice for people of color. And that's actually happening now in Australia. Really? I mean, what are they doing there? So Australia has one of the highest rates of skin cancer in the world. And now many public health authorities have endorsed new messaging, which does include different advice for different skin types.

23:52Epidemiologist David Whiteman has been part of crafting that messaging. And it hasn't been easy. How do you get a public health strategy that is effective but targeted? And that's new territory for all of us. And so we're trying to work out how you do that in a modern society. It's proving to be a challenge. What they've done is create three skin type categories. And the advice is different for each. So people with the fairest skin types. so skin that burns easily and rarely, if ever, tans. Sunscreen should be a part of the morning routine whenever the UV forecast is 3 or above, which as a point of reference is an average early spring day in New England.

24:34Meanwhile, the people with the darkest skin types, so deep brown or black skin, which rarely, if ever, burns, quote, routine sunscreen application is not needed, And, quote, sun protection may be needed if outdoors for extended periods when the UV is three or above. That sounds like there's some measured language in there. So what about in the U.S.? Honestly, the debate seems pretty unsettled in the U.S. You could ask, basically, what's the harm in being cautious and just giving that blanket advice? I think you can't go wrong with that. That's Susan Taylor, professor of dermatology at the University of Pennsylvania and founder of the Skin of Color Society.

25:17She stands behind the blanket sunscreen advice for people of color, arguing that sunscreen still protects against issues like hyperpigmentation and sunburn. And she also argues it protects against other non-melanoma types of cancer, although other experts did tell me that association remains unclear in Skin of Color. We've had conversations in the Skin of Color Society. We've had advisory groups, right? And where we've landed is that people of color should still use sunscreen. But dermatologist Ade Adamson, he chafes at what he calls a maximalist approach. I think that people need honesty. I think that there needs to be voices out there that are just telling the facts as it is and allowing people to interpret those facts.

26:10Honestly, it feels like these questions go way beyond sunscreen. Yeah, absolutely. So what do we take from this? Like, it does seem a bit unsatisfying. Yeah, I agree. I think that for me, this reporting has left me both more impressed with sunscreen as this technical material and an understanding that sunscreen is imperfect. It has limitations, and that is why in public health, in Australia and in the U.S., the message is often something like this. Sunscreen is one component of a sun protection strategy. It's never our first line of defense. Sunscreen's always the last line of defense. Before you even get to the sunscreen, there are lots of other things people should do first to minimize risk, like avoiding peak hours of the day when the UV is at its most intense, wearing hats, staying in the shade.

27:01So bust out that parasol. Totally. If you want to get stylish with it. And wherever the science ends up heading in the coming years, I'm not sure that basic advice will change. Well, Justine, thank you so much for coming on and breaking down the science of sunscreen. It's my pleasure. Thank you for having me. It's been really fun.

27:28That was Justine Paradis, a producer with Outside In from New Hampshire Public Radio. You can find more from that show wherever you get your podcasts. This episode was produced by Ben Rappaport and edited by Jenny Schmidt. It was fact-checked by Greta Pittinger. The engineer was Robert Rodriguez. The rest of the Sunday Story team include Sharon Mashihe and Andrew Mambo. Our supervising senior producer is Liana Simstrom, and our executive producer is Irene Noguchi. I'm Aisha Roscoe. Up first, we'll be back tomorrow with all the news you need to start your week. Until then, have a great rest of your weekend.