#10: Does Sun Protection Work?

Come join me on this very important journey and I hope that you feel empowered along the way . I'm a physician , ironman , triathlete and have published several hundred scientific studies . I'm honored to be your guide . Hundred scientific studies I'm honored to be your guide .

Welcome back everyone . Summer has officially arrived , although in Texas , where I live , it's felt like summer for quite a while . During the summer , we spend more time outdoors , exposed to the sun , and it's natural at least natural for me to think about what the sun exposure does to us .

So today I'd like to explore sun exposure and what the evidence tells us about its impact on our health , and what the evidence tells us about what might protect us from that potential damage . As always , the show notes will have links to some of the studies I'll talk about .

If you're interested , I've started regular health tips of the day about 30-second video reels on sleep or exercise or nutrition or any other topic . Just follow me on Instagram DrBobbyLiveLongAndWell

. So , as always , I want to begin with the take-home messages on sun exposure . First , have fun in the sun . It's great to be outdoors , but protect your skin and protect your eyes . But protect your skin and protect your eyes .

Second , as we will see , the evidence in this area is a bit cloudier than we might want , but I'll hopefully help you find a path through it . The plan for today is to first provide some background on how sun exposure can affect our health , both how long we live and how well we lived .

Next , I will walk through the evidence on what causes skin cancer and skin aging and , most importantly , how strong is the evidence on ways to prevent these problems ? We will also briefly talk about your eyes and how UV exposure can damage them .

Now , I haven't shared this before , but I did want to today that I have no financial motivation for anything I say . You may not agree with what I say and by all means , let me know , but no one is providing money for me to say it . The podcast is free . I don't have and will not have sponsors and will not have paid subscriptions .

Hopefully this will reassure you that what I say is what I truly believe whether I'm right or whether I'm wrong . Many years ago , a colleague shared some advice with me which I've been reflecting on as I've been thinking about how to prepare my podcast moving forward .

She said when you're talking with audiences , data or presenting evidence makes it believable , but stories , anecdotes , make it memorable . Today , I hope that I can do both and , depending upon your thoughts and feedback , it may become a standard approach . So if you can , let me know through my website , that would be great . Do you like this approach

? So let's start with the story . Gail and I live on a ranch in Central Texas , in a town called Dripping Springs , and we spend a lot of time outdoors taking care of the land and the exotic animals and our bed-and-breakfast guests . A few months ago , I had a sore on the top of my scalp .

Now I couldn't see it , but I could feel it , and it seemed to be there for quite a while . For quite a while , I assumed I bumped my head , which happens a whole lot around here , whether it's on branches or any number of hard objects I seem to run into . Well , it didn't seem to go away and I asked Gail what she saw .

She told me about it , took a picture of it and we looked at it together . It didn't look like much , but since it hadn't healed , I decided to get it checked out . Turned out to be a basal cell carcinoma . I'll explain later what this is . But it's a type of skin cancer .

So off to the dermatologist I went , got it biopsied and the skin cancer diagnosis was made . Then to the specialist dermatologist who does the removal . I'm numbed up and don't feel much as he takes it out . Since it was in my scalp he had to pull the edges back together with a bunch of stitches .

Now it wasn't particularly painful , but over the next couple weeks it was pretty uncomfortable and the whole thing turned out to be a somewhat bigger deal than I expected .

During that time I wondered about how I got the skin cancer and whether the evidence to avoid it was very strong , and with that motivation , I dug into the data , the studies and people , and now , of course , I want to share with you what I found , as summer is taking full force

. All right , next section . Let's begin with the damage that sun can cause . So the damage from the sun comes from UV ultraviolet exposure and UVA is the wavelength of greatest problem because it's absorbed deeply in the skin .

Now UV exposure is worse near the water because of the reflections from snow , from sand , and the sun is strongest between the hours of typically 10 am and 2 pm , and even though it's cloudy , 80% of the ultraviolet penetrates clouds . So when we get to sun protection , even if it's cloudy , you'll want to consider doing it Now .

There's no doubt , and we don't need major , major , major studies to know that being in the sun can cause sunburn . It's happened to all of us and everyone we know and we'll see that sunburns can lead to bigger problems later on . Over the long term . Sun exposure ages our skin and what does that mean ?

Well , it makes it thinner , it can make it saggier , we can get brown spots and wrinkles . So there's an interesting study and you know I love my studies . There were 300 women .

Now , one group was told to avoid the sun and the other enjoyed being in the sun , and they examined a whole series of signs of skin aging , like wrinkles , the texture of the skin , pigment changes , and what they found was 80% of the skin damage was directly related or correlated with UV exposure . Now , note it wasn't 100% .

So there is more to aging than just sun . Part of it's genetics , part of it's just getting older , but obviously the lion's share of it related to ultraviolet . Now , okay , so skin appearance doesn't affect how long we live , but it affects our quality of life and how we feel about ourselves .

I mean , as we age , we don't necessarily want to look like we're getting older , and later I'll talk a bit about how we can protect our skin from this photo aging or the sun-related aging .

Now here's the bigger issue Sun exposure can increase our risk of skin cancer , and that's , of course , what sent me down the rabbit hole of trying to understand the issues and then share them with you . A very , very , very brief pathology lesson .

So the skin is composed of a variety of cells and many of these cells can become cancerous like cells elsewhere in our bodies , and the name of the cancer is based on the type of cell it came from .

So two of the skin cancers basal cell carcinoma that's the one I had and squamous cell carcinoma these are ones that can bleed and they grow locally , so they'll grow bigger and bigger and into the areas next to it . Now they do grow pretty slowly . Now they can go into lymph nodes , and very rarely they cause serious harm , and if they're found earlier .

They should be readily removable and curable , and that's what happened with me . Now the third type of cancer , which is again a different cell in your skin , is melanoma . It can metastasize and if it's not caught early , treatment can be really involved and it can even be fatal .

And historically , before some of the better medicines came along , it not infrequently was fatal . So melanoma , which is the dangerous skin cancer even melanoma , if it's caught earlier , can be cured by removing it . But if we catch it late and it's spread , it can be problematic .

Now we want to avoid any skin cancer , clearly , because it's no fun to have to go through the removal , but melanoma is the most important one . Fortunately that was not the skin cancer I had , but you know we're always at risk and so I'll keep getting things checked out . Now , of all cancers , skin cancer is the most common .

There's about almost 5 million skin cancers a year in the US and it outweighs really all other cancers combined . And there are several hundred thousand of those which are melanoma cases , and there's probably over all of people in the United States , over a million people , who have some stage of melanoma . And again , that's the one we really , really want to avoid .

Now . Most skin cancers happen in our middle and later ages , in your 50s and 60s and beyond . Now melanoma can show up in people under 30 . So we all need to be mindful of it , keep an eye on our skin and try to do what we can to really avoid any problems . All right , so this is sort of the background on skin and skin aging and skin cancer .

In the next section I'd like to explore with you , well , who's at risk for skin cancer . Basically , it's people with light skin , and there's a whole grading scheme of light skin to very , very dark skin . But the people with the fairest skin seem to have the greatest problems . On the other end of the spectrum , folks that are black .

They have far less likelihood of a skin cancer developing . Now , one group which you might not necessarily have thought of , who are at risk for skin cancer are Australians . Now , I love Australians , I love the way they talk , and many of them obviously have moved here and it turns out a lot of the research on skin cancer comes from Australia .

Now , when we talked about saunas , we talked a lot about Finland , but here skin cancer research and skin cancer risk seems to be higher in Australia . Now why might that be . Now there's lots of theories and nobody knows the full answer . It might be that they're closer to the equator than we are .

It may be that the people who historically not the indigenous folks , but the folks who moved there had fair skin .

They typically came from Britain and elsewhere , and some blame the hole in the ozone level as the causative factor , and I think that one's been debunked a little bit , but suffice it to say people in Australia are at higher risk and therefore the scientific community has been really focused on that .

So I want to begin to explore the evidence on sun exposure and its relationship to skin cancer . So the risk of getting melanoma and again , that's the bad skin cancer or the really bad skin cancer it correlates with the number of sunburns you experienced during childhood .

Now keep that in mind that there may be a relationship to sun exposure when you're young , to problems when you're old , which is different than the risk goes up as you get older with any time you're in the sun . So what ? This study of studies , a meta-analysis ? There were 51 studies Now .

These were observational studies and , as we've talked about and we'll continue to talk about in future , episodes are not as good as a randomized trial and they basically said did you ever get a major sunburn ? Obviously , we all get sunburn , but some people got ones that really blistered .

Those are what we're talking about as the bad ones and the ones that got sunburn as a child had a 60% increase over those that did not in having a melanoma and they found what we call our dose response . So the more sunburns you got and six seems to be kind of a magic number more than six of these bad ones was problematic .

So again , the more sunburns you had , the greater the risk . Now here's the wrinkle . As I alluded to a few moments ago , I mentioned that the number of sunburns seems to relate to the likelihood of getting melanoma . But that's the number of sunburns when you were young .

Now , if we start to protect ourselves as we get older , will that stop the problem or reduce the problem ? And that's where , as I said , the evidence is a little more cloudy . Now I was talking about melanoma . There's also a correlation between sun exposure and sun burns and the other two non-typically non-fatal ones basal cell carcinoma and squamous cell ones .

Basal cell carcinoma and squamous cell . It's inevitable whenever I talk to folks about UV exposure , they'll ask me about indoor tanning salons it's like , okay , well , they use more protective rays , and is that okay ? Well , interestingly , there's been a lot of studies on this .

In one article it was analyzing 36 studies and they found that there was a 25% to 50% increase in melanoma and the other non-melanoma squamous cell carcinoma in people who were regular suntan booth users . And once again there was a dose response . So more than 10 a year was a lot worse than five a year or once a year .

So if you go once a year before you're going to a big party , is that going to cause skin cancer ? Not likely , but if you're a regular user it can be a problem . And then they also found that suntan booth users , when they did develop skin cancer , it tended to come on earlier than you would otherwise expect .

As I said earlier , it's typically in the 50s , 60s and 70s . So up until this point in the podcast , the data is pretty strong that ultraviolet exposure can cause troubles .

But , as I said , this area is a little bit cloudy and so now I want to talk about where the evidence isn't as straightforward as we'd like . Part of this is that the data is based on observational studies .

So in an observational study you look at people who did something and you compare them to people who didn't do something , and then you follow them forward and you try to adjust for the fact that the two groups may not be identical .

It's really hard to think about doing a randomized trial of being in the sun or not being in the sun and asking people to follow those rules for 30 years . So you're not likely to get great randomized trials on some of the aspects of this . So I like to think about the development of a problem as a series of kind of conceptual links .

Now the first three links the evidence is pretty clear . Link number one sun exposure leads to sunburn . Doesn't take a randomized trial for all of us probably to believe that's true . The second link also pretty good data Sunburns are associated with skin cancer .

And then the third link is also pretty good Studies show that sun protection reduces your exposure to ultraviolet light and the risk of sunburn . So it seems like , oh , we've solved everything , except where the data gets a little cloudy is does reducing that ultraviolet exposure and sunburns lead to fewer cancers ? Here's the problem .

So we know that sun exposure leads to sunburns which can lead to cancer , and now we want to find out . Can we protect ourself against the sunburns which can lead to cancer , and now we want to find out can we protect ourselves against the sunburns and therefore protect ourselves against the bad things we're trying to avoid ?

Well , before we get into the data on whether sun protection works as well as we'd like , let's take a slight detour , which is how do you protect yourself against the sun ? So most people think in terms of sunscreens , and there are different types .

There's the mineral and the chemical , or instead of sunscreens , you can wear clothes or you can just avoid being in the sun . Now there's really good evidence that sunscreens reduce skin aging , like the wrinkles and thinning of the skin .

So there was a randomized control trial of over 900 people and one group had daily sunscreen use and the other group they didn't really require skin protection at all , and they followed them for four years , which is a really good time to see changes .

And they looked at the skin , the fine lines , wrinkles , and they were focused on the left hand , just to keep it very precise , and what they found is the people who were using the sunscreens had 24% less evidence of aging . So the good news is sun seemed to help if your goal is to reduce your skin looking older and older .

Now the data is pretty good that it reduces . Sunscreens reduce the risk of a melanoma . In a randomized trial of 1,600 people in Australia I mentioned before about Australia they showed that sunscreen use did reduce melanoma by 50% not by 100% , but by 50% .

Where it's a little less clear is whether the sunscreen improves other cancers like squamous cell or basal cell . And again , here's another study , randomized trial . There'll be links to these in the show notes , so you're more than welcome to take a look and see what you think .

That showed that SPF 15 reduced squamous cell carcinoma , but not the kind I had , the basal cell carcinoma .

And in a more recent study this was part of the NHANES survey that's done here in the US on a very regular basis they showed that sunscreen use helped people , but long-sleeved shirts or staying in the shade didn't really change the risk of squamous cell or basal cell carcinoma .

Now that seems a little odd because you would think that , yes , the sunscreens might help , but shouldn't also staying away from the sun or wearing clothes ? You would think that would provide equal benefit . But again , the evidence link isn't as powerful as we would like . Suggestive , but not as powerful Now . This may seem counterintuitive .

We made the strong argument that UV exposure is bad and therefore blocking that UV exposure ought to be good . But let me give you a kind of a tasty tidbit for why the protection doesn't look as wonderful as you might think . People who put on sun protection may inevitably stay in the sun longer .

Oh , I don't have to get out of the sun , I don't need to protect my skin because I put on suntan lotion . So these individuals might be out in the sun not just an hour , but maybe two , three or four hours . So then when you look at , do people with sun protection have reductions in cancer ?

It can get murky because maybe those people are actually out in the sun longer . And there's an interesting discussion of this , and again I'll link this for you . The other problem is that , although we may say we put on sunscreen , we may not have done it right .

We may not have put on enough , and we may not and this is often the case reapplied it multiple times a day . So this is why the data aren't as pure or as perfect as we would like them to be . Okay , so

let's now kind of take the evidence and shift to so what do we do with all this ? How does this all net out ? Well , if you think guidelines from national clinical societies are a good thing , then the American Academy of Dermatology . They recommend everybody out in the sun should have SPF 30 or greater sun protection . So that's what they say .

Well then , of course , is which type of sunscreen do you want ? You know , there's the kind of the standard stuff which I mentioned before .

There's the chemical and there's the mineral ones , and those can be $8 a bottle , and there's now these fancy ones that are maybe 10 times the price , with titanium and other fancy things , and they often come in very small bottles .

So the physical ones do create a barrier and they reflect some of the sunlight , and that's the zinc oxide , like we know from the past . But there's now the newer ones with titanium and the chemical ones . They don't so much block the sun , but they convert the rays into heat . The physical ones also do that as well .

Probably there is no difference between the two in effectiveness . There's probably no difference between the zinc oxide and the titanium ones in terms of benefits . Now , it's true that the titanium has these nanoparticles and maybe they absorb a little easier and maybe they don't look quite as awful on your skin , but it's not clear that they're any more powerful .

For me , the best sunscreen is one you're willing to use , because often we walk outdoors and we're like I don't want that greasy look on my skin .

So , whatever you find that works for you , that's what is the right type and ideally you want to apply it multiple times a day and if you're really in the sun and like me in Texas , I sweat like there's no tomorrow , I need to apply it ideally every couple of hours . Now people say , well , I've got this suntan lotion lying around . Is it still good ?

Well , most of it should last three years or so , so I wouldn't worry if it was , you know , last seasons or even the seasons before . I don't think you need to throw them out and start all over . Well , spf , which is sun protection factor , you see all sorts of numbers 15 , 30 , 50 , 100 . Most of the studies look at SPF 30 .

So you don't have to do SPF 50 or 100 . The SPF 30 blocks 97% of the UVB rays . Now the real problem is most of us don't apply enough . You know , if you want to do pretty much your whole body , you need to do an ounce , and most of these bottles maybe have eight ounces , so you're using a lot of the bottle .

So that's actually one of the bigger problems You're not putting it on enough and you're very often not reapplying it when you could or when you should . Now , personally , I like wearing long-sleeve shirts , and I buy the ones that have some SPF protection . I wear ones that are SPF 50 .

And I like those because then I don't have to worry about putting the greasy stuff all over my arms , and then I typically wear something around my neck to protect my neck as well , so I don't have to put quite as much sun protection creams and things on me . Here's another problem .

I'm a man and we men have all sorts of problems in life , but one is that we're not good at sun protection in life . But one is that we're not good at sun protection . Men are , in studies , half as likely to use sun protection as women . Now why might that be ? Well , I think it's sort of our masculine culture .

We think our skin is stronger and we don't need to worry about it . Women , on the other hand ? Many women wear cosmetics , and those cosmetics may have SPF in them , but they're used to putting creams on their skin . Men typically don't .

So if people don't tend to put sun protection on , we men are probably worse at it than others , so we need to think really carefully about this .

All right , so I haven't said anything yet about your eyes , and eyes are really , really , really important . So UV exposure causes eye damage . They can cause cataracts , which are sort of the cloudiness of the lens , and you might then need to get your lens replaced .

Now , uv exposure isn't the only risk factor for getting a cataract , but it is an important one , and the other , probably even more worrisome , is macular degeneration , and that's the most common cause of blindness in people who are 65 and older .

Now , genetics play a role , smoking plays a role , but also UV exposure is a risk factor , and again , I'll have show notes that will have a link to something that supports that . So we need to protect our eyes as well , and wearing sunglasses with UV protection is really the way to go , and pretty much anytime I'm outdoors I'm wearing that .

Now I've spent the last 28 minutes talking about the harms of the sun , but obviously there's some good things about the sun , as we've talked about in our sleep pillar , exposure to sun early in the morning helps our circadian rhythm and may well help your sleep .

It also helps to produce vitamin D , and there's some question like whether sunscreens might worsen your body's ability to make vitamin D . The evidence that sunscreens are going to cause you to be deficient in vitamin D is not very convincing , but if you have any concerns about that , you can get your vitamin D tested in your blood .

It's not routinely recommended , but if you have a concern , by all means talk to your doctor . Well , how about annual skin exams , either with your dermatologist or your primary care doctor ? Well , the question seems pretty obvious . If skin cancer is bad , then seeing your doctor should be good , so you can catch it early .

Well , it's true , the evidence shows that if you undergo screening regularly , you'll find more skin cancers and including more melanomas .

In a large observational study of sort of 600,000 individuals , they showed that if you get screened regularly , you will find more cancers in earlier forms of melanoma , and the likelihood of finding a melanoma will increase almost twice . Well , that seems like a good thing . However , what happens is you may be finding cancers that won't ever cause you harm .

In a future episode , we're going to talk about to test or not to test , and we'll explore this issue further , but there aren't any randomized controlled trials on . Should you get an annual exam ? And yes , you may find things , but that doesn't necessarily mean it's going to change your long-term survival or your long-term well-being .

And the US Preventive Services Task Force , which advises groups on screening , has found really no conclusive evidence that one should have annual screening

. So where do we go from here ? As everyone knows , I love end-of-one trials in ourselves to see what works . We take a baseline assessment of an issue like sleep , we try something new and then we see what happens . Unfortunately , since the risk of skin cancer is a lifetime problem , we can't do an end-of-one study .

We can't try something in the sun protection realm for a month and say , okay , now I know what works for me . So , even though some of the evidence in the logic chain is cloudier than I prefer , you know , the Dermatology Association recommends sun protection . Skin cancer is common . Protecting against the aging process is desirable for many .

Will we , with our sun protection , prevent skin cancer ? Again , the data is suggestive , but not as strong as I would like . Well , this is where I net out for whatever it's worth . I am careful . I do wear clothing and I wear sunglasses with UV protection all the time when I'm outdoors .

I do see a dermatologist yearly and that's definitely going to happen , since I had the basal cell carcinoma . So that's where I net out , so you can look at the evidence and you can decide for yourself what you think . Before we close

, I want to say that we're going to have a new segment in some of the podcasts on fan mail . Thank you for those who've sent comments and suggestions and topics . Now the fan mail option within the most podcast apps allows you to send me a note , but I can't respond to you .

If you want me to respond , and I'm happy to do so , please try to send me a note through my website or on Instagram and then I can respond directly to you . And both of those are Dr Bobby Live Long and Well , and Dr is D-R , not the full spelling .

But I have received a few and since there's no way for me to respond directly to you , I want to at least let folks know for some of these that I received your comments . So one person said that I mentioned a table of exercise program and it wasn't available on my website or the show notes .

Well , that's been corrected , so you can go to the show notes episode on exercise and you can find a handy dandy summary that might be useful to program your week of activities . Somebody asked should we change our activities , our training , the sports we do as we age to spare our bones , joints and ligaments ? That's a good question .

Somebody asked about additives like calcium that's included in milks and things , and whether that's important . Somebody asked what type of multivitamins should they take and what do I take and what dose or how many per day . Somebody asked about the use of psyllium , or how many per day .

Somebody asked about the use of psyllium , which is metamucil , to lower their cholesterol , their LDL cholesterol . So I'm going to reflect on how best to answer these questions . If you send it to me directly , I can certainly answer directly and I may .

I haven't decided and I need your input whether I have special episodes where I just focus on questions or whether I answer one or two at the end of each episode . So I welcome your thoughts about this .

Do send me a note , do send me questions through my website or your podcast app , and I'm particularly interested , if you liked , having a personal anecdote or a story as a way to lead into the podcast . So until next time , may you live long and well , and I am , as always , honored to be your guide on this journey .

Thanks so much for listening to Live Long and Well with Dr Bobby . If you want to continue this journey or want to receive my newsletter on practical and scientific ways to improve your health and longevity , please visit me at drbobbylivelongandwellcom . That's drbobbylivelongandwellcom .