Sunlight and Your Health: An EnLIGHTening Perspective

this ucsd-tv program is presented by university of california television like what you learn visit our website or follow us on Facebook and Twitter to keep up with the latest programs well it's a great pleasure to be here in sunny San Diego and congratulate Carol for putting this outstanding supposing them together for the opportunity to be here and Cedric and all my friends that are that are out here so I'm going to give you a very broad overview about sunlight and health and I knew that I was in trouble because I had this varied audience with varied experience so I went to a physician who's kind of an alternative alternative medicine doc who really I think you all know and respect for his wisdom and I asked him how was I going to do this and thanks to the IT people here we were able to get him to make a comment and indeed I received support from NIH and u-v Foundation and I also a partner with Rob Williams and on two metrics I also get support from the Sun and indeed you an idiot that's what the alternative medicine doc was saying right and so what am I going to tell you about sunlight that you don't already know about because we keep hearing about sunlight being bad for your health and indeed as you heard from Carol both the Surgeon General and the FDA warned us about any exposure to sunlight and the mantra still from the American Academy of Dermatology is that you should never be exposed to one direct ray of sunlight in your life and so the public's view of sunlight these days is certainly like this and indeed if you look at the screen test and you look at risk for skin cancer and concern from our young it really is quite significant in fact when you really think about it I think this kind of slide says it all Wow indeed that's what we've been taught about the Sun and that sun's rays can cause damage to your skin and so no kidding excessive sun exposure will increase risk for skin cancer so there's evolution thinking about Beach we're here in the 50s and the 70s right and new millennium is lots of sunscreen a lot of clothing and so indeed this slide kind of says it all because we were born we evolved in sunlight we've always appreciated the beneficial effects of the Sun indeed this is the bottom line is education right and so sunlight 101 right good the bad and the ugly okay and so when you think about sunlight there is very many beneficial effects but certainly if you're exposed to a lot of sunlight you can have some negative consequences and also you can have some ugly consequences as well so I thought I would explore many of these with you including the role that sunlight plays in making vitamin D so sunlight exudes energy and it's a really remarkable that the amount of energy that's coming out of the Sun and so it's electromagnetic spectrum from cosmic rays all the way up to microwave and radio wave radiation and it's the envelope around the earth that really prevents most of the most serious and potentially harmful rays from reaching the Earth's surface and in fact if you look at the spectrum for sunlight you can see that tiny amount of UV is actually reaching the Earth's surface in fact if you look at radiation reaching the Earth's surface about UVB 0.1 percent UV 84.9% visible 39 percent and here infrared about 56% and so and it turns out that evolutionarily this UVB of course played a critical role in the production of vitamin D so what are the consequences of being exposed to sunlight and to EMR and so if you look at the electric electromagnetic spectrum and you can look at ionized radiation UVC it certainly is used very effectively as a antiseptic in a variety of circumstances including in surgical suites but it's UVB and UVA that we must are concerned about and it's worthwhile noting of course you remember from high school days is that the higher the wavelength that lower the wavelength higher is the energy and so as a result when you're exposed to sunlight what's quite remarkable is that the wavelength and energy right are inversely proportional so that the higher the wavelength lower is the energy and indeed the dependence of wavelength and skin penetration is pretty clear and that is that UVC hardly gets through it at all because mostly absorbed by DNA and protein but visible radiation can penetrate deep into your body cavity and we have not a clue what the consequence of that is although I will be chat sharing with you some concepts about the period and clock genes that are present throughout your body so when you're thinking about light penetration into the skin UVB is penetrating mainly into your epidermis where you're making vitamin D and having a lot of other biological facts including producing nitric oxide UVA penetrates deeply into your skin because it's not efficiently absorbed by DNA and proteins and as a result we'll get to the drama capillary bed but visible light will go basically all the way into your body cavity and when you think about sunlight you always have to worry about the Zenith angle the Sun and the ozone layer because when you're directly above it and you have zero angle you have the most maximum efficiency of UVB and UVA reaching the Earth's surface and in the wintertime say in september/october where the Sun is coming in a more oblique angle it has to go through a lot more ozone and therefore the UVB and UVA is being absorbed and that shows it very nicely here is summer versus the winter and this will have a significant impact especially on the vitamin D story because we know that winter sunlight basically cannot make any significant vitamin D if you live above about thirty degrees 35 degrees latitude and that there's a lot of Association studies implying that winter is the time when many chronic illnesses occur so how does the skin respond to the Sun and I think this shows it very nicely here are two hammerhead sharks and so yep no question about it that when you're exposed to sunlight you will tan and so when you're exposed to UVA it's penetrating through your epidermis UVB is mainly being absorbed by the DNA and protein in your epidermis and as a result what's happening is that initially you develop increase in stratum corneum so these are like little mirrors that are reflecting back the UVA and UVB so that's the first response the second response is that these melanocytes that sit between the dermis and epidermis begin to make packets of melanosomes that begin to migrate upward and to cover the very important nuclei of each of the epidermal cells the tyrosine ace is the engine basically it's the enzyme that makes the polymer melanin which is a magnificent natural sunscreen and this is the mechanism by which that occurs but it's really quite remarkable the melanocytes sit right here at the epidermal dermal Junction and you can see very nicely how these melanosomes basically cap like an umbrella all of the nuclei in the epidermis so the body has evolved over time a very simple and effective way of helping to reduce risk for developing damage to your skin also what's interesting is that melanocytes when they sit between the epidermis and dermis if they're exposed to UVB they principally recognize this signal and they make Malena somes that are going into the epidermis to protect your DNA and proteins but if you're exposed to UVA now penetrating into your dermis the monocytes also recognize this and they begin to produce melanosomes that now migrate downward by doing so if you're only exposed to UVA you could wind up having a lot of Malena somes in your dermis but having very few in your epidermis and even though you are looking normally pigmented and you think that you're being protected from the Sun in fact you're getting blasted potentially by UVB radiation and potentially damning or damaging your epidermis so melanin really does act just like a umbrella to help protect our DNA from damage and we also know that the possible mechanism for melon and synthesis is that they have these dimers form these thymine dimers and that there are enzymes that cause excision and it was shown that when you're exposing melanocytes to UVB that these dimers seem to be a signal for tyrosine ace to increase melanin production so again the body has been very clever and realizing it's exposed to sunlight yes some of the DNA is starting to get damaged its excised and it's those products that are now stimulating melanocytes to make more melanin so when you're out there having a great time if you look at the solar spectrum and IRRI Seema action spectrum and look at the solar spectrum you could see that most of the Eero Thema occurs right at about the range where vitamin D is being produced at around 290 to 315 nanometer radiation but you also will have erythema in the UVA range as well and so at noontime about 15% of erythema occurs as a result of being exposed to UVA 85 percent is due to UVB radiation so UVA causes your Thema and melon ization but you need about a thousand times more compared to UVB so bottom line is simple which is you never want to burn right so how much you want to get exposed you never want to look like this and coming from New England of course it can't look like that right indeed can Sun damage your skin there's no question that excessive exposure initially increases the risk for actinic keratoses right which are these kind of scaly lesions and continued exposure can lead the basal and squamous cell carcinoma the ugly of course is wrinkling right and what happens is that the UV a particularly penetrating deep into your dermis is causing destruction of your elastic tissue and as a result the springiness of your skin begins to collapse because of the cross-linking that's occurring as a result of being exposed to UVA both its direct effect as well as its anti as well as its oxidant effect the collagen matrix so how have humans perceive the Sun there's no question that early on that certainly we've always appreciated the beneficial effects of the Sun in fact here Helio therapy Hippocrates prescribed Helio therapies sunbathing for both medical and psychological purposes and and asked up who's good friend had provided me with a lot of her slides and I'll note that in each of the slides that I'm using from her presentation so for humans of course the story really begins with the Industrial Revolution back in England in the 19th century most scientists thought that the effect of sunlight on the skin was due to heat generated by exposure in 1801 UV radiation was actually discovered by Ritter he Holmes did an experiment and he showed that if you were exposed to sunlight on your hand and looked at the temperature that you would have pain blisters an erythema if you took sunlight with a cloth and even had a higher temperature that there was no pain blisters or erythema so he had the first insight that exposure to sunlight on the skin was having some kind of physiologic effect and in fact he showed very nicely that black Grenadians hands exposed to sunlight had no effect provided the first insight that sun's radiation not Heat had a biologic effect on the skin and that melanin was protective from sun burning back in 1820 1820 black skin pigment defense against scorching effects of the Sun also it turns out that sadecki at the same time in Warsaw Poland began to realize something because children in Warsaw had a high incidence of rickets and so he did an association study realizing that maybe there was an association with sunlight and rickets and he realized that children living in warsaw in the inner city had a high incidence of rickets but the children living in rural areas outside of warsaw didn't and so he said was strong and obvious was the influence of sun on the cure of rickets and the frequent of the disease in densely populated towns where the streets were narrow and poorly lit 18 22s near decade now who was going to believe a Polish physician in 1822 right in 1897 Vincent began treating lupus vulgaris which is TB infection of the skin with ultraviolet radiation and he got the Nobel Prize in 1903 and in fact Vincent phototherapy became very popular where people were put being put outside and exposed to the direct rays of sunlight and here are good some good examples of before and after and indeed you could see that this was quite a dramatic impact and as a result realised that photo therapy had significant importance so helio therapy was born right and Rowley ER in particular was a very strong proponent and again if you look at Helio therapy in year 1933 there's over 165 different diseases which sunlight proved to be beneficial for treatment right from lowering blood pressure and as well as having effects on your immune system in 1889 in Boston 80% of infant's had evidence of rickets and so that was a major issue and it was whole schinsky in 1919 this Viennese physician who realized that you could a radiate children the mercury arc lamp and actually treat rickets I mean at the time people thought this guy was a nut because how could exposure of your skin have any impact deep on your skeleton in fact he was clever enough to realize if you irradiated one arm that you could actually demonstrate curing the rickets in the other arm so he knew something was being made in the skin entering the circulation and having a direct effect and so here is some of the earliest x-rays of whole schinsky October 1st 1918 right and here November 12th 1918 just exposure for six weeks to of the violet radiation was considered to be an insoluble cure for rickets so two physicians finally realize if you can radiate people with ultraviolet light wine that sunlight and indeed they showed hessen Unger in New York City 1921 published in JAMA that they could cure rickets with sun exposure this led to a novel concept our government actually set up an agency back in 1931 sending brochures to parents to recommend you put your children outside for sensible sunlight in order for them prevent rickets we also know that kids with rickets were more likely to have upper respiratory tract infections as well as dental caries and all of the benefits for sunlight were beginning to be appreciated in the 1930s 1939 this is typically what was typically happening in many hospitals around the world and then also you could go to your local pharmacy and to buy one of these lamps and they were using them to radiate kids and in fact spurred II came out with a mercury arc lamp that you could bring home you would have goggles on your children they'd be exposed to sunlight and would prevent them from getting rickets but it was Harry Steinbach who thought of something different which is if you're going to radiate people in animals why not I radiate the food to impart antibiotic activity because he realized that cows don't put vitamin D in their milk and so he started the concept of a radiating milk so the magic vitamin D Steinbach process or radiation with ultraviolet light this led them to the concept of a radiating yeast and irradiated yeast were then used for leavening bread which was a good source for vitamin D and so everybody began to appreciate the healthful benefits of vitamin D and it was all coming from exposure to ultraviolet radiation from some source even bond bread was using irradiated yeast and demonstrating that it had adequate vitamin D and recommended if you didn't want your children outside every day naked that you better eat vitamin D fortified bond bread it so as a result of Steinbach who realized if you get add the precursor or gossler all to milk and irradiated and you could have anti ricotta and then ultimately when vitamin D was easily made and inexpensive they started fortifying milk with vitamin D basically it eradicated rickets and as a result people no longer thought about the healthful benefits of vitamin D coming from the Sun in fact if you look at the 1900 to 1940 phototherapy flourished then there was swallowed up by pharmacology so the introduction of penicillin basically really kind of heralded pharmacology and that everybody now thought all you need to do was to take a pill and that you could cure all ills in fact the dermatologist today still tell you you should never be exposed to one direct ray of sunlight in fact if you ever put your child outside without a sunscreen you could wind up on America's most wanted for child abuse so does sunlight have any beneficial effects so the good production of vitamin D feeling well-being regulating circadian rhythm and so what about the big deal about D deficiency you're going to be hearing a lot more about this from others over the next two days but even back in O seven Discover Magazine considered vitamin D to be very important for overall health and welfare as well as Time magazine Ted and biggest medical breakthroughs more benefits of vitamin D and we're now recognizing that wherever you publish whether it be New England Journal of Medicine or fitness magazine the super vitamin has certainly got a lot of attention and even teens are appreciative of the sunny vitamin D and so as you'll be hearing over the next two days that not only is rickets the issue with sonics black of sun exposure but we think that vitamin D deficiency increases the painful bone disease osteomalacia may increase risk for diabetes multiple sclerosis rheumatoid arthritis infectious diseases hypertension heart disease common cancers you may recall from that slide on Helio therapy and that hundred and sixty-five lists almost all of these are on that list they appreciated back in the 1930s that sun exposure helped reduce risk of these chronic illnesses so vitamin D is a sunshine vitamin whether you're an amphibian reptile avian species curiously we did a study in chickens I had a bunch of hungry graduate students and decided where do chickens make their vitamin D the thinking was originally they were making it on the surface of their feathers because they were preening themselves and that they would then be cleaning themselves in consuming the vitamin D but that didn't make any sense physiologically and in fact we found out that actually it's only on the top of the head where there's very little feathers and about ten times more Pro vitamin D on the legs then it would be on the back so mother nature knows exactly where sun exposure occurs and where to produce vitamin D certainly lower primates still depend on Sun for their vitamin D requirement but curiously cats that are covered from head to tail with fur can they make any the answer is no it was demonstrated that cats have no pro vitamin d3 in her skin and as a result they totally depend on what they eat for their source of vitamin D so our hunter-gatherer for fathers outside everyday of course we're making vitamin D so as people migrate to north and south of the Equator the question was were they being able to make enough vitamin D and it turns out that these dark hair and Neanderthals actually weren't dark and hairy at all but they likely were Celtic that they probably had a mutation of their melanocytes receptor and as a result we think probably you'll be hearing a lot more from Bruce Hollis about this is that the reason probably for the disappearance of skin pigment as people migrated north and south of the Equator is that here's a healthy pelvis of a normal female this is a pelvis of a female likely had infantile rickets and as a result has a very poor pelvic outlet flat pelvis difficult time with child birthing now we showed many years ago you can't make good vitamin D in a winter time and so I took my daughter on safari to Kenya and sure enough you can make it year-round but you cannot remove this from your taxes as a medical expense but I'll tell you what this sailor wire he's perfectly designed for his environment and indeed when you compare and contrast no question my gene pigment devolved and so how do you do it well when you're supposed to sunlight it's the precursor of cholesterol on your skin absorbs ultraviolet radiation converting it to vitamin D now you may ask if you're on a statin and you prevent cholesterol biosynthesis does it have an impact the answer is No statins don't get into your skin to affect this process now she's a lot of bad habits and a lot of worries but one thing that's amazing about Sun induced vitamin D you can never become vitamin D toxic because you make all these photo products we're doing research right now so this issue of doing more research is that why do you make all these photo products it's likely that they have biologic effects and in fact Rebecca Mason in Australia has suggested that some of these that are hydroxylated may have anti-cancer activity and we've reported very similar types of studies so you can never become toxic from sun exposure but it is true because I'm asked a question if you take vitamin D as a supplement or you expose the sunlight is it make any difference well the difference for sure is that when you make it in your skin it lasts two to three times longer in your body that it does when you take it as a supplement so what about bone health there's no question that it's essential whether you're a rodent or a puppy or a cow or a chicken all vertebrates need a source of vitamin D and even the pet industry because it's about 10 million households in the United States that have pet reptiles they know that they need vitamin D and certainly you always have them indoors so of course industry rose to the occasion so you can go to your local pet shop and buy simulated sunlight that has UVB radiation for 40 bucks so that your pet reptile at home will make vitamin D in its skin now we don't do this very nursing on residents no no but we do this for our pet iguanas this is the problem because it's assumed if you have a healthy diet you're getting all the vitamin D that you need but we and others have shown many years ago that no matter what diet you have in the United States if you're not taking a significant amount of vitamin D supplementation no child in the United States could get enough vitamin D from their diet Dairy is fortified but there's only 100 units and even the Institute of Medicine says you need 600 units a day so you'd have to drink six glasses of milk a day also orange juice is fortified with calcium and vitamin D and it's again a good source mushrooms they make vitamin D we don't exactly know why but the mushroom industry thought this is a great idea so you could go to your local produce section and now get a source of vitamin D by having UV exposed mushrooms and so in the summertime you're making lots of vitamin d but that Zenith angle the Sun is important so directly above you that 0.1% UVB is coming through you're making vitamin D in wintertime however it's a little bit different right you wear more clothing and now it's coming in a more black angle and these UVB photons have to get go through a longer path length and most are absorbed and in fact we went on to show that if you put samples outside of human skin or these ampules in the spring summer and fall in Boston you're made vitamin D but in wintertime couldn't make any at all indeed we did a study even in Edmonton Canada and showed that that was extended from October through April is when you could not make any vitamin D no matter how much time you stood outside now my colleagues say well this stuff with the test tubes doesn't cut it anymore we need evidence-based medicine so I went to my students say I need a person to volunteer to go up on the roof in the middle of winter to prove you can't make lighter than any vitamin D so I finally got a volunteer you make none right indeed my daughter had the better part of this from Middlebury College down to Miami you could make it year-round so basically if you live above it later Georgia or Los Angeles California you basically cannot make any significant vitamin D in your skin and 10:00 a.m. to 3:00 p.m. is the only time for the same reason because the Zenith angle designed to so orb-like so what about sunscreen use no question if you put it on properly it reduces your ability to make vitamin D by about 98% and it's not rocket science it's preventing absorption of UVB into the epidermis so you make very little vitamin D 9 to 95% your vitamin D is coming from sun exposure you never want to burn right and how do you know how much you're really going to make ways this little pop is just to pop at your bellybutton doesn't happen anymore so we did a study and we showed if you take healthy adults put them in a tanning bed and get a minimal erythema dose which is a light Pinkus to your skin 24 hours later it's equivalent to about 15 to 20,000 units of vitamin D so your skin has a huge capacity to make vitamin D in fact we went out to show that all skin types exposed to simulated sunlight was more effective in raising blood levels of 25 hydroxy D compared to taking a thousand units of vitamin D - or vitamin d3 daily also aging definitely decreases your capacity to make vitamin D by about 75% but it turns out that yep even burnsy here can make vitamin D because we took old Biddy's will amount on our verandah and show that they increase their blood levels of 25 hydroxy D and here and I studied by Ian Reed 15 to 30 minutes a day raised their blood levels why is she screaming because it's been thought that if you go out in the Sun and then you go and take a bath immediately afterwards you're going to wash it all off this precious vitamin D turns out you make it in your actively growing layers not to worry you could definitely bathe after you're exposed to sunlight the sunlight provide you with your vitamin D no matter what your ethnicity Peak blood levels are at the end of the summer the nadir is at the end of the winter five to 15 minutes because if I'm going to get a mild sunburn after 30 minutes arms legs abdomen aback followed by good sun protection just like what she's doing here sensible sun exposure also pay late with his girlfriend pink tation is very efficient in absorbing UVB and they need to be outside at least 4 to 10 times longer to make enough and we showed very nicely if you take Caucasians versus African Americans exposed to the same amount of UV they didn't raise their blood levels at all for vitamin D they need to be exposed to 5 to 10 times more to barely raise their blood levels of vitamin D so are there other benefits to being exposed to UV are maintain skin health it's well known in the dermatology profession psoriasis that if you take a patient with psoriasis and expose them to UVB that indeed here are twenty patients six weeks 80% responded why do people feel good when they're exposed to sunlight do human skin cells produce a happy substance in response to sunlight right does human skin produce beta-endorphin and so we asked this question many years ago and showed that if you take cultured human skin cells and exposed to UVA we saw no appearance of beta-endorphin but exposed to UVB we did does human skin produce beta-endorphin and enter the bloodstream to make you feel better a very nice study done by John Paris show that sunlight beta-endorphin you exposed to sunlight simulated sunlight beta endorphin levels increase in your blood stream and sure enough you can find it in your bloodstream Brazil will be going back to your brain to make you feel better about a 44% increase in beta endorphin levels so you can make beta endorphin in your skin and indeed if you're thinking about exposure to UVB radiation that the P OMC this Pro OPA mental Courtin peptide is not only produced in your pituitary gland but it's also produced in your skin so Minsky showed very nicely and also it produces ACTH which I will be explaining to you why that has important ramifications for autoimmune diseases including multiple sclerosis and type 1 diabetes so when you think about beta endorphin and opiate peptide when you're exposed to sunlight and you're making it in your skin you definitely are feeling better because it's likely getting back into the brain to improve pain relief feeling of well-being and relaxation endorphins also are good for wound healing cellular differentiation and pain and here's a study that showed very nicely changes following a single dose of UVB terms of beta endorphin levels and when you look at now track zone which is a antagonist to opioid that you can see very nicely that you can actually make much more beta endorphin and have a marked effect on brain in terms of feeling better than you can by taking an opioid and so also endorphins or natural pain and stress fighters if you look at these symptoms from fibromyalgia pilot study suggested that UV may have some potential in reducing chronic pain and improving mood in persons with fibromyalgia like symptoms sunlight deprivation and depression seasonal affective disorder there's a lot of information out there to suggest that it's the intensity and duration of visible radiation in the blue range in particular going through the retina and and having an effect on the production of melatonin so circadian rhythm if you look at the acute effects that you will increase serotonin alters body temperature heart rate alertness cognitive performance brain blood flow EEG responses food and water intake so all of these things like obesity and chronic illnesses have been associated certainly with people not feeling well and circadian rhythm control could very well have a significant impact and indeed if you look at sunlight on pain stress and depression they showed very nicely that if you're exposed in the summertime the sunlight compared to the winter to the Syrah tonin levels are much much lower in the winter than they are in the summer and you certainly feel better in the summertime also there's a very nice study that showed that the 24 year old with PMS symptoms that was exposed to bright light was having a beneficial effect on PMS so exposure of light to the brain regulating melatonin we know has a significant impact on SI D but can the skin perceive bright light and trance for the signal to the brain and so is the biologic clock also in your skin and the answer is probably yes indeed if you look at science many years ago they did a really interesting study where they took a fruit fly and what is all these purple dots these purple dots are clock genes clock genes are transcription factors that regulate gene activity and they showed in some of the earliest life forms that basically every cell in this fruit fly had a clock gene so likely when they're exposed to sunlight that all of these cells are being responsive to that so maybe exposure to bright light to the skin in a sun tanning bed for example could set your biologic clock and so in 2000 we published an investigative dermatology journal when we took human skin cells and looked for the production of period one that we could show very nicely that skin cells do in fact express period one gene as well as clock genes and that they seem to be regulated by exposure to simulated sunlight so does UVB alter clock gene expression period one gene expression we went on to show that UVB has a significant impact on these transcription factors why it's possible that remember I had mentioned that visible light penetrates deeply into your body cavity and that it's quite possible that some of these clock genes are being regulated by visible light as well we also know that UVB irradiation may help hypertension and indeed again from astha is ultraviolet radiation and cardiovascular disease seasonal variation and mortality caused by cardiovascular disease always occurs mainly in the winter months and the least is in the summer months in June and July and August seasonal variation in serum cholesterol levels again they lower in the summertime than they are in the wintertime seasonal variation and blood pressure again up in down as a function of season solar UV and blood pressure wast an in 1979 first suggested an inverse relationship between blood pressure and latitude indeed he showed that the lower the latitude that you lived lower was your blood pressure and we went on to do a study and ask the question if you took hypertensive individuals and expose them to UVB radiation or UVA radiation would it have an effect on blood pressure and six weeks measured blood pressure so we took healthy adults put them in our tanning bed with UVB and UVA and three times a week for three months serum 2002 CD for the UVA group because we use the poly carbonate shield to block out the UVB in the placebo group the UVB group increased their blood levels of 25 hydroxy D into what we consider to be the healthy range of above 30 nano grams per ml UVA group on blood pressure we saw no impact on diastolic or systolic but UVB group a significant decline in both the diastolic and systolic blood pressure so at least in this very small study we could show that UVB and not UVA acute under acute circumstances significantly decreased blood pressure and we published this in Lancet and we went on to show that even out to nine months that we were able to help reduce blood pressure both systolic and diastolic over time also vitamin D has an important role to play on myocardial on blood pressure and Essos sclerotic plaque formation and so this could be part of the explanation for why sunlight reduces risk for cardiovascular disease but don't forget about n o because n o has a very significant impact as well so not only does 25 hydroxy vitamin D have a significant impact on cardiovascular disease but n o has as well and it works in a variety of ways because it can impact on vascular blood flow so the role of electric oxide for vasodilation uv-induced Lana Genesis you have inflammation apoptosis wound healing but vasodilation is certainly a significant player that probably is having an effect on blood pressure in fact UVA in this study long-term demonstrated that there was a significant decline in blood pressure independent of UVB UVA liberates nitric oxide from the epidermis shown very nicely here by eminent histochem astray and also demonstrating that the more UVA the skin was exposed to more vectric oxide was being produced calculate nitric oxide release from skin stored by season and latitude again if you look at the season and latitude the lower the latitude more nitric oxide is being produced also curiously if you look at the heme part of the hemoglobin exposed to UV radiation it actually will release Co carbon monoxide which also can cause vasodilation among having other biological facts also there's a calcitonin gene related peptide as well as P om C that I've talked about making ACTH and a whole host of factors and it's been demonstrated by Schley Minsky and others that when you're exposed to simulated sunlight that the skin cells Express these genes and make these products and indeed even substance P is being produced in the skin it's a neurotransmitter neuromodulator and it's a vasodilator so what about the immune system no question that there's a lot of impact of exposure to ultraviolet radiation Marga Kripke showed this over 30 years ago that it causes alteration in your immune function that she believed in a positive manner so UV effects on other diseases like MS it turns out that we know that the higher the latitude that you live higher is your risk for developing multiple sclerosis in fact if you live above about 35 degrees north latitude for the first 10 years of your life 100% increased risk of developing MS for the rest of your life no matter where you live on the globe a study done out of Harvard Nurses Health Study showed that nurses that had the highest intake of vitamin D reduce risk of MS by 41% also studies have shown that the lower vitamin D status was associated with higher relapse risk in MS patients but also that's not the whole story because the study done by Hector de luca's group showed that if you'll exposed mice that you gave them a encephalitis to mimic multiple sclerosis and you expose them to UVB versus UVA that he could show very nicely that whereas the 25 hydroxy vitamin D levels did not change that the group receiving uva radiation had a significant impact on the encephalitis activity so that there is more to the story than simply vitamin D that vitamin that the UVA is also having an effect on the immune system so for multiple sclerosis we also know that exposure to ultraviolet radiation will down-regulate t helper cell activity and of course have some an additional impact on immuno suppression and so there's a lot of information now suggesting that when you're exposed to simulate a sunlight that ACTH is being produced and curiously that one of the major drugs to treat multiple sclerosis is ACTH so it's not a surprise that Drina cortical tropic hormones may not only impact on this autoimmune disease MS but may have an impact also on rheumatoid arthritis and indeed even in osteoporosis 80 ACTH has been demonstrated to increase bone mineral density and also we know that vitamin D status is inversely associated with rheumatoid arthritis UV effects on other diseases using these Melania curtains so look at energy homeostasis analgesia inflammation thermoregulation cardiovascular regulation neural muscular regeneration food intake body weight control right type 1 diabetes we've known also a cost that the higher the latitude that you live and you'll be hearing more about this from dr. wahrman later on is that the higher is your risk for developing type 1 diabetes and it was opponent back in 2001 in Lancet showed schoolchildren taking I'm sorry infants taking 2,000 units a day during the first year of life reduce risk of type 1 diabetes by 88% right and look at this as the Finns worried about the intoxication they continued to decrease vitamin D intake and bingo the incidence of type 1 diabetes on the rise ever wondered about the immune system turns out that macrophages activate vitamin D and they make it for good reason there's no question 18-49 cod liver oil and TB vitamin D protects against TB so when you infect the macrophage with TB Adams and Marlins showed several years ago in science that you first turn on the enzyme to activate vitamin D to 125 dihydroxy vitamin D tells the cell to make a thousand a defense and protein that specifically kills infective agents so we think that's probably the reason why solariums were so effective for patients with TB the flu season coming upon us again it's always been thought hope Simpson that there's a seasonal stimulus in fact at the peak flu season of course is at the nadir of your 25 hydroxy vitamin D study done out of Yale showed that if you have an average level of 38 nanograms per ml reduced risk of upper respiratory tract infections twofold if one is a infection here in schoolchildren in Japan 1,200 units a day reduce risk 42% also asthma has been recognized to be may be impacted by exposure to sunlight because it does have an impact on t-cell activity also that if you look at immune suppression there's both a peak at around 300 nanometers and there's one here out at around 370 nanometers so UVA radiation definitely has an impact on immune function and that could be part of the explanation for DeLuca's observation with encephalitis in mice and having an effect so when you think about photo immuno suppression there's a lot of both negatives and positives but the bottom line is that is in fact is a positive for immuno health I'm not going to talk very much about visible radiation because you're going to be hearing about this from dr. Lynch shortly but low energy photon therapy with venous legs still sub leg ulcers double-blinded placebo-controlled trial marked improvement using this laser type of ecology and similarly when you're looking at red and blue laser light and looking at collagen synthesis in your skin and looking at the impact before and after on wrinkling a significant benefit that you'll be hearing more about so why should you care about all this well actually once your vitamin D is made in your skin it has to get activated and every tissue and cell in your body has a vitamin d receptor and of course we now a recognized thing that part of the reason is that it affects a variety of genes and you can be hearing a lot more about this from other speakers but sure enough we've always known exposure to sunlight reduces risk here in San Diego for cancer in fact can sunbathing reduce your risk 19:41 it was a Polly who showed exposure to sunlight if you lived northeast you're more likely to die of cancer than if you live down south and of course cedric garland showed many years ago that you just increase your vitamin D intake to a thousand units a day projected reduction in colorectal cancer by about 50% reduced breast cancer Nurses Health Study showed they said the highest blood levels 50 percent lower risk at a very nice study done out of Canada showed that if you are exposed to the most sunlight during your early years in life for women reduce risk of breast cancer by as much as 69 percent possible connection we've always known that prostate cells right we know that they can now activate vitamin D and so many cells in your body have the ability to activate vitamin D and that it induces its own destruction so it never enters the circulation so it inhibits cancer cell growth and it's estimated up to 2,000 genes are directly or indirectly regulated by the active form of vitamin D in fact we did a study and showed in healthy adults for 12 weeks getting 2,000 units of vitamin D a day looking at almost 23,000 genes if you look at before and after all of these genes in blue are turned off they're now turned on and vice versa and we went on to show that up to 80 different metabolic processes from DNA repair apoptosis oxidate stress metabolic processes anti-inflammatory activity associated with this process phaedra genes right with vitamin D so adequate sunlight and vitamin D is necessary from birth until death right just like what our hunter-gatherer forefathers were doing the study was done to show their average blood level forty to sixty nanograms per ml look at this think about disease burden and vitamin D deficiency and sunlight deficiency is really quite significant worldwide look Johnny a special time play to get your vitamin D we always appreciated the beneficial effects of the Sun so I'm a proponent of sensible sun exposure how'd you get the message out to the public I wrote a book back in 2004 and just like Carol I do not advocate tanning right but those that wish to do should do it responsibly and like I said you definitely increase your risk for non melanoma skin cancer from excessive sun exposure but everybody worries about melanoma the most deadly form but as we pointed out most melanomas occur on the least Sun exposed areas and remarkably occupational sun exposure decreases risk for melanoma and here it is in Journal investigative dermatology 2003 lifetime sun exposure is associated with a lower risk of malignant melanoma rights our ancestors view of the Sun a little bit different than dermatologists view right no question that they recommend sun protection have you ever been on rounds with on orbit ologist no question about indeed Schultz epitomizes good common sense and here Lyons getting no from his mom are you sitting in sauna hope so a little son is good as long as you don't overdo it perhaps 10 minutes a day this time of the year was about right he was right on target no question about it right this is what's happened to our sentence but demonized for more than 40 years unchallenged right son and humans to that 1927 people were out there enjoying themselves right and now look at 2013 right to sunlight must moreover be the greatest importance in maintaining normal health a fact far too little taken to heart even today right slips off stop message in Australia guess who this is 40 percent of Australians are deficient because this is an Australian dermatologist on vacation and they found 87% vitamin D deficient at the end of the summer have you ever wondered about this nothing can stop them no nobody couldn't stop alright you're right you know what he was right about right vitamin D deficiency is associated with right dementia right indeed sunlight and vitamin D deficiency schizophrenia depression and dementia as well as Alzheimer's disease has now been associated so you can get the same healthful benefits of sunlight from diet supplements and maybe drugs right hopefully convinced you you cannot indeed what do I do just like all my family members the best source is getting some sensible Sun time of day season a year latitude worrying about skin protection worrying about sun burning right and so why not develop an app and so Rob Williams who is here today develop this app and I partnered with him in doing so and indeed for free d-minor info will tell you not only if you're making vitamin D but warns you to get out of the Sun so that you don't damage your skin and so I like all my family members sun protection on face but not on arms and legs and I also recommend that we increase our vitamin D intake I take about 4,000 units a day but level about 60 to 90 grams per ml lack of adequate sunlight and vitamin D deficiency is a major impact on your health right any one of these chronic illnesses turn out to be associated with inadequate amount of vitamin D or inadequate sun exposure right there is no downside to obtaining sensible sun exposure right you don't need to be a genius to notice we need sensible Sun and vitamin D supplement recommendations this is not a hypothesis right we don't need more research right I route wrote a book recently a new one about the vitamin D I'm grateful to my family for all of their support and letting me be here today and thank you for your kind attention you

Channel: University of California Television (UCTV)

Views: 197,399

Keywords: sun, sunlight, health, vitamin D, UV, sunburn, tan

Id: oAAlMYWtF_s

Length: 54min 11sec (3251 seconds)

Published: Wed Jan 07 2015