The dark side of sunscreens

Here in London, UK, the weather today has been quite summery. And it’s this time of year where we generally begin to see a rash of articles in the press warning us about the perils of sunlight and the need to slather on our sunscreen. People generally use sunscreen to prevent burning. But public health campaigns often allude to the use of sunscreens for the prevention of skin cancer too.

However, the evidence base for the effectiveness of sunscreens in skin cancer prevention is scant to say the least. Back in 2000, the International Agency for Research on Cancer in Lyon, France, held a meeting to discuss the role of sunscreens in skin cancer prevention. Before we look at their findings, here’s a quick summary of the main forms of skin cancer.

There are 3 main sorts of skin cancer, squamous cell carcinoma (carcinoma is a type of cancer), basal cell carcinoma, and malignant melanoma.

Squamus and basal cells carcinomas are quite-strongly related to sunlight exposure, as partly evidence by the fact that they are most common in typically sun-exposed parts of the body like the face, ears and back of the hand. They make up about 90 per cent of skin cancers but are responsible for only about 15 per cent of skin cancer deaths. The relatively non-deadly nature of these cancers is essentially because they are not typically very aggressive and are often spotted quite early means that they usually won’t.

Malignant melanomas represent only about 10 per cent of skin cancers but account for about 85 per cent of skin cancer deaths. Most of them do not occur in typically sun-exposed parts of the body, though sunburn is a risk factor. When people use sunscreens to prevent skin cancer, it’s usually melanoma they’re thinking of.

Anyway, back to the International Agency for Research on Cancer meeting in 2000…

A report of the panel’s findings was published in the Scandinavian Journal of Work and Environmental Health [1]. The panel concluded that sunscreens could prevent sunburn (should hope so too), and that there was evidence that they could help prevent squamous cell carcinoma. There was a caveat though: protection was only evident where individuals had not used sunscreens to extend their time in the sun. Actually, a lot of people use sunscreens in this way. When people coat themselves in sunscreen on the beach or by the pool, one usual intention to allow themselves to stay longer in the sun without burning.

But what of the role of sunscreens in melanoma prevention? The paper refers to epidemiological evidence (studies that look at associations between things) that find sunscreen use was not associated with a reduction in the risk of moles (higher numbers of moles are a risk factor for melanoma). In their press release the panel members state this:

Several relevant epidemiological studies have shown significantly higher risks for melanoma in users of sunscreens than in non-users. This paradoxical observation could in part be due to the fact that users of sunscreens deliberately spend more time in the sun than they would otherwise have done. Thus, the protective effect of sunscreens can be outweighed by overexposure based on the false assumption that sunscreens completely abolish the adverse effects of UV light.

In light of these findings, the Working Group concluded that sunscreens prevent sunburns and may reduce the risk of squamous cell carcinoma, but only if they do not mislead people to extend their exposure to sunlight. The Working Group also put forward several recommendations in relation to the use of sunscreens. Principal amongst these is that use of sunscreens should be one part of a comprehensive sun avoidance strategy that includes moving into shade when the sun is near zenith and the use of protective clothing. As part of a comprehensive skin protection strategy, sunscreens with a protection factor of 15 or more should be used.

In other words, don’t rely on sunscreens to protect you from melanoma, because they probably won’t, and may actually increase risk. A more recent review concluded that studies link sunscreen use with increased risk of moles, malignant melanoma and basal cell carcinoma [2].

I have not used sunscreen for 20-odd years, opting to seek shade and wear appropriate clothing when the sun is at its hottest. Because sunscreens can give us a false sense of security, it might be wise to use it sparingly. One situation where it can come into its own is for the face and ears when swimming in a pool or sea. If protection is required elsewhere, I’d go for clothing designed to protect the body from UV rays.

References:

1. Vainio H, et al. Cancer-preventive effects of sunscreens are uncertain. Scandinavian Journal of Work and Environmental Health 2000;26(6):529-531

2. Autier P. Sunscreen abuse for intentional sun exposure. Br J Dermatol. 2009;161 Suppl 3:40-5

36 Responses to The dark side of sunscreens

  1. HighlySkeptical 1 May 2012 at 7:53 pm #

    Dr. Briffa:

    Understanding the above, what about the use of sunscreens to prevent aging? They do prevent sunburn, as you say. Since I always avoid the sun and wear a hat & sunglasses, I’m still concerned about aging, particularly on the face, neck, chest and hands. One look at Brigitte Bardot today is enough to dissuage anyone from sun worship, and sunscreens surely prevent the long-term damage to collagen and elastin that we would otherwise see.

    Why do you not recommend sunscreen to prevent aging? Ty!

  2. Kerry 2 May 2012 at 1:47 am #

    Thank you for this informative article!

  3. Ted Hutchinson 2 May 2012 at 3:14 pm #

    People who want to understand how to improve their NATURAL SUNSCREEN POTENTIAL may enjoy reading Wellness mama Eat Your Sunscreen? and Healthyfellow Natural Sunscreen Options but do be aware none of the strategies suggested are instant, so allow at least 8~12 weeks before expecting to see improved resistance to UVB and always take care to cover up before any signs of sunburn are visible.

  4. John Duggan 4 May 2012 at 10:46 am #

    Is there not also the possibility that the suncreams themselves are promoting an increased incidence of skin cancer? If you think about it, we just slather a pile of chemicals onto our skin and then blast them under a hail of UV and other powerful rays from direct sunlight. Would it be a surprise to learn that the suncream itself was have a bad reaction with the skin? Just asking.

  5. Rufus Greenbaum 4 May 2012 at 12:17 pm #

    There is a hypothesis that boosting your Vitamin D level with a supplement may help to protect against melanoma – and also reduce your sensitivity to sunburn.

    In his book “Athlete’s Edge”, Dr John Cannell of the Vitamin D Council reported that his daughter has fair skin and was very sensitive to the sun. He suggested that she took 10,000 IU per day of Vitamin D3 for a month and then see what happened in the sun. She did this and she found that she was less sensitive to the sun.

    Professor Julia Newton-Bishop of Leeds University, UK is a specialist in melanoma and reported that those with higher levels of Vitamin D had better outcomes from treatment.

    Whether higher levels of Vitamin D – taken as a supplement – protect against this form of cancer have yet to be proven.

    .

  6. Xenia 4 May 2012 at 1:13 pm #

    @HighlySkeptical,

    sunburns and aging are basically one and the same thing. It is all about free radicals. You have all the sunscreen that you’ll ever need built in in right there in your skin and in your body. And, as dr. Briffa always says, you can enhance this by eating the right stuff.

    Avoiding sugar and grains and starches in general (i.e. a truly low carb diet where carbs come mainly from the vegetables and an occasional piece of fruit or a healthy tuber) is what keeps your sking young. Not avoiding the sun! I am 54 and spend as much time in the sun as I can, without ever using sunscreen, and I have practically no wrinkles. Of course, you have to start carefully and build your protection step by step. 10 minutes, then the next day 20 and so on. (And not trying to get a tan in one week, like most people, after staying away from sun most of the year.) Sun makes my skin plump and young looking. Sun is the biggest rejuvenator there is, and it’s free. It is also great for weight loss.

    Another tip: go organic. Eating clean and avoiding all artificial food (think God-made versus man-made, and do not go even near to what came from a factory, including the sun-screens) will do wonders for your skin.

    The same goes for skincare products. Buy only organic and never use skin creams with SPF. NEVER! If you wish you can use organic coconut or avocado oil before sunbathing so the skin doesn’t get too dry. This is of course not protection against sunrays.

    To ensure skin protection from within, it helps to take supplements like lycopene (or make sure to eat a lot of organic/home made tomato paste or juice in summer months), astaxanthin, pomegranate, resveratrol and SOD (Super Oxide Dismutase). Big help are also vitamin C – because it helps build collagen -, a good multivitamin/multimineral, preferrably from whole foods, and of course, omega 3 supplement.

    As for sunglasses, it has been proven in a study that in people who wear them, vitamin D cannot be activated properly. So you are getting the sunburn, but none of the benefit.

  7. Deborah Booth 4 May 2012 at 1:59 pm #

    At long last someone “officially” is looking at the insanity of lathering your skin in awful chemicals, and assume you are safe from sunburn, and, John Duggan has pointed out, this could be more damaging to the skin than the sun. I once spent four months living with a group of Australian Aboriginal basketmakers in the bush of Arnhem Land, and even they, with very dark skin sought shade at midday, or wore a hat or a cloth over their heads and shoulders.
    Personally I find I don’t burn much theses days as I spend so a lot of time outside in the garden or walking with just a vest top on, whereas the modern diet and office lifestyle makes for pasty skin…. The more sun the more vitamin D too. And as for the woman worried about ageing, that too is a problem of modern life – I live in Galicia, north Spain, the peasant farmers here look fabulous with their wizened workers skin, far more beautiful to me to see a life lived as a real human being rather than a fashion model. At 60+ I love my age spots!

  8. Ted Hutchinson 4 May 2012 at 2:00 pm #

    @ Rufus Greenbaum But Professor Julia Newton-Bishop work confirmed the optimal amount of vitamin D required by the body as at least 60nmol/L. to get EVERYONE in the UK above that level would require around 2000iu/daily for all adults.
    To meet basic daily needs (calcium absorption) ideally 100nmol/l (around 4000iu/daily)
    To deal optimally with inflammation 125nmol/l (5000iu/d) and
    To supply vitamin D replete human milk to babies 150nmol/l 6000iu/daily (maybe more)
    Dr Briffa recently supplied a link to CITYASSAYS Birmingham NHS pathlab postal Vit d 25(OH)D test £25 UK £30 international that will enable you to see if the amounts I’ve suggested work out in practice for you.

  9. Penny 4 May 2012 at 5:53 pm #

    So what is the cause of malignant melanoma?
    I have had (now clear) this form of cancer, and after 6 years I am still confused by it.
    I continue to take Vit D3 drops regularly.

  10. Donald Tiso 4 May 2012 at 8:09 pm #

    Xenia
    please supply the source for your claim , “As for sunglasses, it has been proven in a study that in people who wear them, vitamin D cannot be activated properly. So you are getting the sunburn, but none of the benefit.” I have read a considerable amount of vitamin D research & never heard of this

  11. Ted Hutchinson 4 May 2012 at 8:26 pm #

    @ Penny So what is the cause of malignant melanoma? Genes and ethnicity 75% of cases occurs on relatively unexposed sites, ie feet of Africans. Melanoma occurrence decreases with greater sun exposure but increased by sunscreens.
    The reason we must never get burnt by sun is acute exposure of skin cells to ultraviolet A (UVA, 320-400 nm), the oxidising component of sunlight provokes an immediate increase in the available pool of intracellular labile iron (LI) that appears to play a key role in the increased susceptibility of skin cells to UVA-mediated oxidative membrane damage and necrotic cell death.
    Which is why we need to be using the anti-oxidant anti-inflammatory properties of Vitamin D3, Omega 3, Melatonin, Curcumin, Green Tea etc. instead of slapping on noxious chemicals. Skin protection against UVA-induced iron damage by multiantioxidants and iron chelating drugs/prodrugs. Part of the trouble is that as UVB creates vitamin d3 from 7 dehydrocholesterol near the skin surface UVA is processing newly made cholecalciferol into suprasterols the body doesn’t use. If we stay too long in the sun all the newly made Vit D3 near the skin surface has been degraded so by the time we burn there is none left to deal with the inflammation.
    Ideally we need SHORT exposures of skin that usually remains covered so when we dress the newly made D3 is protected from UVA (by clothes) and has time to be absorbed into the body.
    Bear in mind IRON overload may be part of the problem so Give Blood – do something amazing, not just to help others but also to offload excess iron regularly.

  12. Frederica Huxley 4 May 2012 at 8:32 pm #

    @John Duggan – you are quite right! Have a look at the list of common ingredients in sunscreens: http://www.greenlivingtips.com/articles/127/1/Sunscreen—protection-or-poison.html As a result, I believe in ‘internal sunscreens’ – astaxanthin and loads of antioxidants!

  13. Ted Hutchinson 4 May 2012 at 10:16 pm #

    @ Frederica Huxley
    That list of ingredients is extremely worrying.
    Apart from the Zinc oxide, which has a large particle size and remains on the skin surface, all the others will probably be measurable in urine just hours after application.
    Just as well I don’t use sunscreens as I’ve improved my natural sunscreen potential and over the winter I regularly have short sessions on a UVB rich sunbed to keep my skin hardened.
    For those who have a sun holiday planned but insufficient time to prepare your skin fully (do try to do your best as every little helps) you may be interested in this recipe for home made sunscreen bars.

  14. Judith Fage 4 May 2012 at 11:50 pm #

    What advice though would you give to a child in New Zealand. Obviously all the usual precautions are taken – big hat, long sleeves – but actually keeping out of the sun all the time is not practical.

  15. mamaprophet 5 May 2012 at 12:10 am #

    Ted, I have never been able to understand what the iu thing is , how do I know what amount daily of vit D to take..most pkts say two tablets daily .thanks

  16. Ted Hutchinson 5 May 2012 at 12:26 am #

    @ mamaprophet
    Do be aware Vitamin D3 is FAT SOLUBLE so the forms that are carried in oil, either in capsules or as drops are likely to be better absorbed. Though taking vitamin D with FOOD (esp the largest meal of the day) may increase uptake.
    Tablets are the least well absorbed option.
    If you’re in the UK then Amazon or BigVits have 5000iu oil-based capsules or drops at reasonable prices. I’ve been getting mine from IHERB but the price differential now isn’t so great.
    Dr Cannell is happy with dry powder filled capsules and the contents of these can easily be added to kids/elderly peoples drinks/foods though you can also do that with the drops. if you’re the “mamaprophet” who has a mum with dementia then it may be an idea to bake some biscuits or make some ice cream “fortified” with effective amounts of vitamin D3. Cholecalciferol is very robust and withstands baking and freezing.

    RDAs for vitamin D are listed in both International Units (IUs) and micrograms (µg or mcg); the biological activity of 40 IU is equal to 1 µg or mcg
    So if your Vitamin D capsule has 10µg or 10mcg = 400iu
    500iu=12.5µg or mcg
    1000iu=25µg or 25mcg
    so my 5000iu capsules are 125µg or mcg
    By the way I’m a but miffed as my results came back from CityAssays today and despite the fact I take 5000iu/daily AND I have short regular UVB exposures through the winter I’m only 113nmol/l or 45.2ng/ml So I’ll have to increase my daily intake to 7,500iu while it remains cold, cloudy and wet and retest later in the year, hopefully after I’ve had a bit of sun.

  17. John Duggan 5 May 2012 at 10:44 pm #

    For as long as I can remember, the Cancer Society of Australia has been urging people to “slop on” sunscreen at 2 hourly intervals. I would be very surprised if public behaviour in this regard has not been influenced by this message, over the last 20 years or so. However, the information on their website http://www.cancer.org.au/cancersmartlifestyle/SunSmart/Skincancerfactsandfigures.htm
    that melanoma rates increased 1993-2003 by 6.8% in women and 18.7% may be an indication that they have been barking up the wrong tree.

  18. Frederica Huxley 5 May 2012 at 11:21 pm #

    @Ted Hutchinson – It is my understanding gleaned from grassrootshealth.net that the higher your starting vit D level, the higher daily iu needed to raise your levels! Also, as London, let alone the rest of the UK, is above 50º latitude, there is no UVB between October and May. My April reading was 78iu; my husband’s was 56iu – it may be that as he is 3 years older than I am, that he needs more than the 5000iu we have been taking daily!

  19. Frederica Huxley 5 May 2012 at 11:25 pm #

    Sorry, Ted, I just reread an earlier comment of yours, and realised you got your UVB in the winter from a sunbed!

  20. Ted Hutchinson 6 May 2012 at 9:50 am #

    @ Frederica Huxley
    Without the sunbed I expect my levels would be the same as your husband. May I suggest you take 3 x 5000iu every 2 days so you average 7500iu/daily and your husband take 2 x 5000iu daily until your 25(OH)D results are above 150nmol/l.

  21. Deborah Booth 6 May 2012 at 8:07 pm #

    Judith Fage – Looking at the photographs of my Australian early childhood, Queensland in the early fifties, I notice that I always have a shirt and shorts on, Grandmother always a wide brimmed hat, my parents always trousers and shirts except in the sea of course. I remember being out of doors most of the time, but semi covered, (by the look on the photographs)…. it occurs to me that all this melanoma nonsense has made people so wary of the sun that children never get enough sun now, and a lousy diet too, that they probably have no natural defence against the sun, and the rare moments they are allowed out in it uncovered they risk sunburn!
    I always allowed my kids in miserable grey UK to be outside most of the time, I don’t remember them having sunburn even in the summer.

  22. cancerclasses 7 May 2012 at 1:41 am #

    Skin cancers are caused by UV interacting with oxidized cholesterol structure in skin that is damaged by intake of trans fat processed vegetable oils and trans fat loaded processed “food”.

    “Trans-fatty acids can block the body’s ability to use healthy Essential Fatty Acids (EFAs) in the production of eicosanoids and they lessen the transfer of the life-giving nutrient, oxygen, across cell membranes.5 Sufficient transfer of oxygen is crucial for cellular health, prevention of cancer, energy, and a healthy immune system.

    In 1939, The American Journal of Cancer published that eating trans-fats produced cancer when skin was exposed to ultra-violet rays. Your skin needs unadulterated parent omega 6 EFAs (skin contains NO omega-3), but most people have been consuming trans-fats or excessive amounts of omega 3 instead, so their skin (and other tissues) are deficient in EFAs, causing it to be susceptible to UV rays that can lead to the development of cancer. It is important to understand that your skin doesn’t utilize omega 3 EFAs (like in fish or flax oils), which is one reason why I recommend a formula with a higher balance of organic, cold-pressed “parent” omega 6 than omega 3.” http://goo.gl/rUUTN

  23. Josh 7 May 2012 at 6:54 am #

    I prefer not to use sunscreens due to the chemicals in them. Instead I opt to keep my skin covered, wear a hat with a brim, stay in the shade if possible, limit sun exposure and eat wholesome, organic foods (very light on grains, sugars and starches).

  24. John 7 May 2012 at 10:13 pm #

    @Highly Skeptical- Part of the problem with using sunscreen to prevent aging is that lots of sunscreens only filter out UVB, and not UVA. UVB burns (and also produces vitamin D), while UVA ages. If you’re using UVB block only, you might be soaking up much more UVA than you would naturally, and aging your skin faster. It’s also possible that whatever sunscreen you choose could have some chemicals in it that age the skin faster. If you choose to use sunblock, you should look for a broad spectrum block, one that protects against both UVA and UVB.

  25. David Mitchell 8 May 2012 at 12:12 am #

    I am highly interestied in this subject and read as much as I can about it because I have very fair skin and burn easily. First, humans evolved under the sun and during most of that evolution we did not wear many clothes, if any. Second, 20 minutes of near full-body sun exposure between 10 and 2 will give the average person with fair skin and Northern Europenan ancestry, about 20,000 IU of vitamin D. (Photons simulate cholesterol in the surface of the skin to create a precursor to vitamin D which then goes to the liver to be fully processed. A caveat, do not bathe immediately before and for at least 2 hours after sun exposure.) Third, there are chemicals in sunscreens which mimic estrogen and could be causing more cancers. Fourth, in lieu of careful, short-term sun exposure for vitamin D, vitamin D3 supplements, but especially good old cod liver oil (make sure the manufacturer has not stripped the natural D and A out and added synthetics) works really well. Fifth, there is, among other things, a direct relationship between pancreatic enzymes and killing cancer cells. But, because that enzyme is needed to help digest protein, one needs to have a period of about 12 hours, out of 24 hours, where they are not digesting any protein. Go to Topicalinfo: Natural Skin Cancer Overview (http://www.topicalinfo.org/Skincancer.htm) for more information.

  26. Robert Fenwick Elliott 12 May 2012 at 4:26 am #

    Here here to all of this. I am spreading the word via http://phenell.wordpress.com/2012/05/12/killer-cream/

  27. Margaret Moss 30 May 2012 at 9:05 pm #

    Yes, do have some sun exposure, don’t use sunscreen, do protect yourself with clothes and shade, and do take vitamin D3 oily capsules. However don’t take cod liver oil. The liver of the fish may be contaminated, and too much vitamin A is harmful, not just in pregnancy.

    I too heard that sunglasses prevent the eyes receiving a message that prompts the body to respond properly to sunlight. Whether this is true I do not know.

  28. D.M. Mitchell 30 May 2012 at 11:20 pm #

    Cod liver oil can be contaminated. But go to the Weston A. Price Foundation site to see their recommendations. It can also be stripped of natural A and D and replaced with synthetic. Be careful. It is almost impossible to get too much vitamin A, especially if taken with D. Again, check out the WAPF site and also the Dr. Yourself site by Andrew Saul. If you are getting a good quality source of cod liver oil you can’t go wrong.

  29. D.M. Mitchell 30 May 2012 at 11:25 pm #

    And, as to sunglasses, I too have heard that since we didn’t evolve wearing sunglasses and that there are many different rays other than UVA and UVB that our eyes need to “see”, then we shouldn’t wear sunglasses. That is, our ancient, pre-sunglasses, ancestors didn’t all go blind in old age from the natural effects of sunlight.

  30. Margaret Moss 25 March 2013 at 1:20 pm #

    Unfortunately you can have too much cod liver oil. Some babies died in the 1940s, because of the high doses used in Britain. Some people are still affected by the high doses the state gave them then, and recover from severe illness on limiting their vitamin A and carotene, and taking good quality vitamin E. One I know was sectioned under the Mental Health Act, and recovered in months.

    Some people have a highly active bcox enzyme, which breaks one beta carotene molecule into 2 molecules of vitamin A. The full name of the enzyme is beta,beta-carotene-15,15′-oxygenase. We store vitamin A in the liver, and too much damages liver cell membranes. Vitamin E protects the cell membranes from retinoic acid. We are protected from vitamin A by retinol binding protein, but some people do not have enough of this.

    Vitamin A comes in different forms, as the alcohol, retinol, the aldehyde, retinal, and the acid, retinoic acid. Efficiency at changing between these forms may vary between individuals. The enzymes involved are alcohol dehydrogenase, aldehyde dehydrogenase and aldehyde oxidase. Too much retinoic acid is a problem. It is removed by glucuronidation, but people with Gilbert’s Syndrome are inefficient at doing this.

    Retinoic acid increases the actvity of glycine N-methyltransferase. GNMT increases homocysteine production, which increases the risk of neural tube defects in babies. Folic acid, vitamins B1, B2, B6 and B12, zinc and magnesium are protective, as together they reduce the homocysteine level.

    We are individuals, with different genes and so enzymes of different efficiency. Anyone advising on nutrition needs to be aware of this. One man’s meat really is another’s poison. Differing nutritional status also affects susceptibility.

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