Here is the sun: Defend our summer rays

Watching cricket with daddy during the last summer of his life, Skin cancer ads were in high rotation. Huge black melanoma cells separated and raged through bustling arteries as we sat there in awkward, painful silence. These same cells were rushing into his body and he would have died in the fall. "There is nothing healthy for a tan," said the urgent and formal voiceover.

Dad was the kind of guy who, proudly, had never sunbathed his life. He claimed to have been burned in the sun only once, in Cairns, in 1942, at the age of 12. By contrast, when I had that age, in the 1970s, tanning was almost a competitive sport. You could burn your first coat in late spring, peel a layer and get ready for the summer. My brother had a melanoma cut last year, one of 14,000 Australians to do it in 2017. It is said that it is the "national cancer" of the world. Australia and that it is also cancer of my family. Aside from the deadly lung tumor of a first cousin, I can not think of any other cancer than a related parent.

You would think that I would be slap-slop-slapping with the best of them with my fair-skinned kids. And me, yes, but every time I bathe at factor 30, I can not help but wonder if it feels good. World melanoma rates continue to rise. Australians under 40 are the only demographic group where it is declining, demonstrating the driving effect of the country's innovative "Slip, Slop, Slap" campaign, which began in 1981. However, I was amazed. , to find that this is not the whole story. Fewer people die, but when researchers plunged into statistics from Queensland's general practice clinics, they found that the number of cancers in young adults was higher than that of my generation at the same age.

At the same time, many new research on the benefits of the sun have nothing to do with the well-known but probably overestimated benefits of vitamin D for diseases such as heart disease, diabetes, cancer prostate, breast cancer, obesity. and multiple sclerosis. People who have more "sun vitamin" in their system have fewer of these diseases. Yet giving vitamin D pills in clinical trials seems to do almost nothing to fix them. This has suggested that vitamin D may well be an indicator of the amount of sun you receive and that there may be something more beneficial to you. And many smart people have questioned the urgent claim that a tan was not healthy.

The first standing. Almost no one ever said that there was something healthy about sunburn. "Do not burn yourself" remains as imperative as ever. Beyond that, however, the story becomes much more interesting. So, I read literature, after one quote to the next, and I come across this line of the Cancer epidemiology, biomarkers and prevention Journal, published by the American Association for Cancer Research, in 2011. "Despite public opinion, the scientific evidence that sunscreen prevents skin cancer is controversial." That makes me stop, have a coffee, ask the woman, "The evidence that a sunscreen prevents skin cancer is controversial." Who knew?

For example, in 1995, a study in Sweden of 400 patients with melanoma and 600 without cancer showed that sunscreen users were 1.8 times more likely to develop melanoma than those who did not. never used. "Our results support the hypothesis that sunscreens do not protect against melanoma," the authors concluded. Critics explain this result and other similar results by the fact that sunscreen users stayed in the sun longer. But is not it the goal? We can make fun of these results in Europe, because what would they know about melanoma? Australia is the melanoma capital of the world. Right? False. This title actually belongs to the land of the long white cloud. New Zealand, whose majority of the population lives further south than the NSW-Victoria border, leads the world in melanoma mortality rates. Queensland would win if it were a country, but as a country, Australia came second. Norway third. Swaziland is sixth. Unlike other skin cancers, melanoma is slippery and complicated.

The types of skin cancer 10 times more common and 100 times less lethal, basal cell carcinoma and squamous cell carcinoma, are directly related to the amount of sun that you have had in your life. These are the ones that are regularly torn from people's noses and hands, the most exposed parts of the body. While we have known since at least the 1970s that melanoma is a cancer of office workers like my father, rather than outdoor workers. And it strikes them on parts of the body that do not see much sun, but are sometimes burned, like the torso of men and the backs of women's legs.

The thing is this: while melanoma rates tend to increase as you get closer to the equator, the rates of many other diseases decrease. It was reported as early as 1950 that the United States had four times more deaths from multiple sclerosis (MS) at 40 degrees from the equator than at 30 degrees, which, in Australia, equates at the latitudes of Launceston in Tasmania and Coffs Harbor on the same road. NSW North Coast. A study by the University of Oxford in 1961 obtained similar results by studying the European ethnic populations of the southern hemisphere, including Australia.

In 2004, Dr. Michael Goldacre of Oxford University felt that an interesting way to study the link between MS and the sun would be to look for correlations between skin cancer and MS. He found that skin cancer was 50% less common among people with MS. This result does not prove anything, but it raises an intriguing question: does the sun protect against MS? Associate Professor Ingrid van der Mei of the Menzies Medical Research Institute of the University of Tasmania had started working on this issue in the 1990s. "In the 1960s, we knew that it was There was a slight gradient of latitude for MS, but at the time, we did not know that ultraviolet light could really affect your immune system, "she says.

"They stopped the research for about thirty years, and then in the 1990s, there was this whole field of photoimmunology where we realized the immune effects that the sun could have."

Australia was a great place to watch, as many people with the same pale complexion lived between, for example, Cairns in the tropics and Hobart, where she was. And when she started to correlate the numbers, they piled up. Tasmania had six times more MS than northern Queensland. But she found an even stronger correlation by calculating the number of sunny days in her key places.

The temperature and the precipitation did not seem to have any influence. This led to a more detailed study of the history of sun exposure of MS patients compared to those who did not have it. She discovered that greater exposure to the sun during childhood seemed to reduce the risk of developing MS. She also found that the link between a lack of sun and MS was stronger than the positive link between too much sun and melanoma. "I do not know why," she said. "It just shows that the link between MS and [lack of] the sun is really strong. "

All skin cancers combined kill about 2,000 Australians a year, mostly seniors. Multiple sclerosis is not fatal, but it most often affects women in their thirties and causes a lifetime of severe and severe debilitation. Currently, 25,600 Australians are serving the sentence in perpetuity, up 20% in just seven years, at a cost of $ 1.75 billion, almost triple the economic burden of melanoma. Van der Mei's idea that sunlight was more closely related to MS than melanoma was the subject of much criticism. They rightly pointed out that our memory of sun exposure in children was rather fragile, but that the essential evidence showing that melanoma was caused by sun exposure came exactly of the same type of study.

Van der Mei has conducted several other studies, showing in 2010 that MS relapse decreased as vitamin D levels increased. Will vitamin D stop MS? The first global vitamin trial to prevent MS is underway in Australia and New Zealand. But smaller studies conducted abroad have shown that the administration of vitamin D to patients in the early stages of the disease had no benefit. It has been known for about a century that vitamin D deficiency is the cause of rickets. The increase of vitamin D above a concentration of 50 nanomoles per liter has not brought any additional benefit to the bones, which has therefore become the desired level. Few other benefits of vitamin D were known.

But in the first decade of this century, vitamin D was hot. Numerous studies have shown associations between this book and a real manual full of ills. These may perhaps be better summarized by a 2014 review of the BMJ (formerly the British Medical Journal) which examined 95 studies involving nearly 900,000 people. He concluded that for every additional 25 nmol / L of vitamin D in the blood, the number of all-cause deaths decreased by 16%. The most important benefits have been observed in heart disease, lymphoma, upper gastrointestinal tract cancer and respiratory diseases. This was even true for melanoma. Call it the Sunshine paradox. You are more likely to contract sun disease, melanoma, and die, if your sun's vitamin intake is low. He found that vitamin D deficiency caused more health problems in the United States than alcohol and lack of exercise.

The largest study ever done on vitamin D deficiency in Australia found that 58% of women in southern states had a disability in the spring, in the dark of winter, but even in summer, 42%. The authors recommended safe sun exposure as the best way to fix it.

Vitamin D pills have been put forward to combat the effects of lack of sun. Australians spend $ 150 million a year. With all this debate about the quality of vitamin D and the deficiency of the population, the race was launched to prove that vitamin D pills would heal all kinds of ailments.

However, in recent years, the results of randomized controlled trials have been consistently disappointing.

Despite the fact that low levels of vitamin D in the blood were strongly associated with poor health, taking vitamin D tablets did not contribute much to the improvement. Not even for osteoporosis, the complaint for which it is most often prescribed. But the poor results of vitamin D trials have opened the door to a more dangerous idea. That is the sun, beast.

In the 1990s, Scott Byrne, currently associate professor at the Westmead Medical Research Institute in Sydney, was preparing his doctorate on the causes of skin cancer caused by sunlight. It seemed to disable the immune system, allowing skin cancers other than melanoma to proliferate. "That's why sunlight is such a powerful carcinogen," he says. "It can both damage the DNA needed for cancer development and inhibit the very immune response that helps us fight these cancers." During his doctorate and postdoctoral research in the United States, the young Australian discovered that one of those responsible for this immune suppression, the "regulatory B cells", was activated by UV rays.

The miracle drugs of modern melanoma treatment, immunotherapies, engage the patient's immune system to fight cancer. Some do this by disabling these same regulatory B cells. One of the side effects of immunotherapy can however be an autoimmune disease, whereby the strengthened immune system becomes uncontrollable and begins to attack the patient's body.

Byrne became fascinated by this yin-yang aspect of ultraviolet radiation, the way he caused cancer and fought autoimmune diseases. "The best drugs we have to treat multiple sclerosis, type 1 diabetes, rheumatoid arthritis, etc., are drugs that suppress the immune system, we have opted for the suppression of the immune system. sunlight and autoimmunity. "

When he fell on the latitude gradient of multiple sclerosis, this sparked his interest in knowing what was going on. "There is obviously something unique about this thing we are exposed to – we have evolved to live in the sun."

Using mice with an MS-like disease, Byrne's team from the University of Sydney showed in 2016 that UV light activated regulatory B cells and suppressed the disease. This was a major breakthrough, as others had already shown that vitamin D had nothing to do with it. "We do not propose and we certainly do not want the message to be the following: we need more sunlight," said Byrne. "Because we know that sunlight causes skin cancer and that it is a very big problem in this country.

"In the long run, everyone seems to be moving towards precision medicine. This is the personalized medicine where a patient goes to his GP who has all the information – his lifestyle, his genetic profile – and will be able to tell that person & # 39; You must have X rays of sun, at this time of day, three times a week. & # 39; But we are far from that. "

Byrne's work touched only the surface. It unveils a list of other immune mechanisms unrelated to regulatory B cells known to be activated by sunlight. "One of the questions scientists always ask me at conferences:" Hey, you just told us that sunlight is immunosuppressive. Why then do not we cause infections when we go out in the sun? "And the answer is that ultraviolet rays actually activate other defense mechanisms against these types of infections, protecting us from these infections." There is strong scientific evidence, for example, that rays Ultraviolet light may be the source of influenza in the summer, and sun therapy was sometimes a surprisingly effective treatment for TB before the era of antibiotics.

In Western Australia, Professor Prue Hart was working on the same ideas as Byrne. She and other researchers at the Telethon Kids Institute in Perth have shown that simply exposing obese mice to UV rays makes them significantly thinner and reduces markers of metabolic disorders such as type 2 diabetes Hart had previously published research on low vitamin D levels in children: by and large, at age 14, children with low vitamin D were significantly more likely to suffer from asthma, d? eczema and allergies. But she also knew that it was proven that vitamin D tablets solve these problems. She suspected that a low vitamin D content was not the cause of their poor health, but was instead a marker of low sun exposure; this UV light gave another advantage.

She received funding to recruit 40 people in the early stages of multiple sclerosis. However, the Perth sun was not a good place to find multiple sclerosis patients and it only listed 20 subjects. Vitamin D supplements were given to all 20 to eliminate this variable. Then, three times a week for eight weeks, half of them were stripped and placed in an upscale sun booth to give them the equivalent of a few minutes of sunshine in the summer – the same treatment that dermatologists give people with psoriasis their skin (another disease that seems to have increased in recent decades and has a strong gradient of latitude). The dose increased steadily as the skin tanned. After one year, seven of the ten people in the treatment group had reached the full form of MS, while the ten people in the group who did not have UV radiation developed the disease.

The low numbers meant that it was not statistically significant, but the study, published in 2017, was appealing enough to attract the attention of dermatologist Richard Weller, professor of dermatology in Scotland. Weller, like all good dermatologists, felt that "we should all live in caves and never let a photon hit our skin". But he was studying the mechanisms of skin's behavior in the sunlight and was looking at nitric oxide (NO), a simple molecule that had earned three pharmacologists the 1998 Nobel Prize in Medicine for discovering the importance that He had taken it to widen arteries, regulate blood pressure, fight infections, initiate erections, prevent blood clots and act as a signal in the nervous system. Like vitamin D, NO was hot.

Weller then discovered that the skin did not release NO in the body when it was exposed to the sun. As a dermatologist, his first thought was that it probably played a role in skin cancer. "But in fact, I found that the most important thing was that nitric oxide released by the skin to the sun lowers blood pressure," he says. "The importance of this is that high blood pressure is the leading cause of premature death and disease in the world today. And sunlight – regardless of vitamin D – lowers blood pressure. "

A 1998 German study – published in the British medical journal The lancet – had exposed a group of people with mild hypertension to the summer sun equivalent on tanning beds three times a week for six weeks and another group at the sun equivalent of # 39; winter. After three months, blood pressure was normal among the 18 people in the summer sun group, while the sun-winter group remained hypertensive. The difference was supposed to be vitamin D, but again, many attempts to produce the same effect with pills failed.

As a graduate doctor, Weller worked for a year in Cairns and found that Australians seemed healthier than the British. "You attribute that to your sporting lifestyle, to your athletic prowess, but it's a bloody lie.You are a bunch of virgin batons.You smoke, you drink too much.You're just like us, British." All this has led him to think about the role of sunlight in longevity. "So then I went to look at the data and, here, all the data is that the more you have sun, the longer you live." There is good data in Scandinavia showing that skin cancer patients without melanoma, skin Basal cell cancer, in particular, have a longer life expectancy than people who have never seen a doctor. "It refers to a study of 30,000 women – but not men – followed for 20 years , which revealed that, along with exposure to the sun, life expectancy increased – up to 2.1 years – mainly because of less serious heart disease and other causes non-cancer deaths. In fact – and do not try this at home – women who smoked and took a lot of sun lived longer than non-smokers who avoided it.

"When you are diagnosed [non-melanoma] Weller explains your skin cancer, your life expectancy increases. " So, the first thing I say to my patients when I diagnose these problems is: "Congratulations, you have basal cell cancer, you will leave my consulting room with a longer life expectancy than when you entered. That tells us two things: first, I am a bad dermatologist; Second, I am a good doctor because what matters is having a long and healthy life. Yes, you may have wrinkled, aged skin with ugly scars from skin cancers. You look old, but by God, you are old. "

Blood pressure also has a latitude gradient. "More sunlight equals lower blood pressure, whether you're looking at populations around the world or people depending on the season … if I did what my colleagues in dermatology want and everyone lives in a cave and that the skin cancer is completely eradicated, it has a percent of the deaths due to heart disease or stroke, we would be late .. And if everyone lived in a cave, you still could not to eradicate skin cancer. "

In Australia, you are 19 times more likely to die of all heart diseases than of all skin cancers. The highest rate of heart disease deaths in 2015 was in Tasmania at 257 per 100,000 population, the lowest in the Northern Territory at 111 per 100,000, although other states are not strictly latitudinal. In Scotland, the multiple sclerosis rate is one of the highest in the world, and the Orkney Islands in the Far North – where one in 170 women have the condition – have the highest rate. It was therefore natural for Weller to attempt to replicate Hart's study in which patient research was easier. "If we can show that it works, we have a safe and inexpensive treatment for MS.Worldwide, we have phototherapy units in dermatology departments."

I asked Weller what he would do with his children if he lived in Australia. He pointed out that sunburns in children are a risk factor for melanoma and that most people should continue to slap. His children come from Ethiopia and even in Scotland, they made compulsory the application of sunscreen. "Every year, I have to send a letter to my kids' school to say," Relax, give sunscreen to someone else. It is Scotland. It is raining. Be realistic. "

Then it becomes controversial. "There is absolutely no evidence that sunscreen saves lives." Weller talks about all-cause mortality: all lives saved by avoiding skin cancer can be outnumbered by those lost because of the net effects of sunlight deprivation.

Earlier this month, the Pacific nation of Palau joined Hawaii prohibit sunscreens containing various chemicals, including oxybenzone and octinoxate, which are considered harmful to young corals. Sunscreens are not just sitting on your skin. They are absorbed by the body and enter the circulation system. A study of breast milk in Switzerland found that 85% of the 54 samples on which UV filters were found correlated with mothers using sunscreen or, most commonly, other cosmetic products containing filters. UV.

Some sunscreens have heated up a bit in recent years for using nanoparticles and others causing allergic reactions. Perhaps more disturbing is their potential for hormone disruption. The website of the Cancer Council of Australia states that "there is no evidence that chemicals approved for use in Australian sunscreens disrupt the endocrine system". He cites a review of the literature by the Therapeutic Goods Administration in 2001. Of course, there has been some scientific research over the past 17 years.

Dr. Joanna Ruszkiewicz of the Department of Molecular Pharmacology, Albert Einstein College of Medicine in New York, completed the final analysis of all studies on endocrine disruptors of sunscreen. I found her via Skype in Peru, where she was hiking.

Yes, she was wearing sunscreen that day. She thought that sunscreen was important. But his analysis contradicts very clearly the statement of the Cancer Council that there was no endocrine disruptors in sunscreens. However, she stated that the lack of research meant that the magnitude of these effects remained unknown. Would she wear it if she was pregnant? "No. And if I had a child, I would not put it to him before the age of five."

For all the vigor with which sunscreen has been pushed on us, there has been only one randomized controlled trial on its efficacy against melanoma. Professor Adele Green performed it in Nambour, Queensland, in the 1990s, and when I read her article, she was convincing. Green recruited 1621 residents of the Sunshine Coast City and asked half to apply sunscreen daily to factor 16 on the head, neck and arms for five years, and the other half to do what they've always done. Ten years after the end of the study, eleven members of the group who received daily sunscreen had developed melanoma, compared to 22 in the control group, which is only changing to "statistical significance".

Senior scientist at the QIMR Berghofer Medical Research Institute in Brisbane, Green is one of the world's leading skin cancer experts. She has devoted much of her career to the subject since her PhD in the 1980s. A 1981 article in The lancet had pointed out the lack of direct evidence that the sun had caused melanoma. In an effort to remedy this, Green began an innovative study in which she selected 183 patients with melanoma and matched them to 183 people of the same age from the same suburb of Queensland. Everyone was asked to remember all episodes of severe sunburn in which the pain persisted for more than 48 hours. The main finding was that you more than doubled your risk of melanoma if you had six or more serious burns in your life (like me). You multiplied it by 1.5 with two to six serious burns. Mais le facteur le plus déterminant pour déterminer si une personne avait un mélanome plutôt qu'une autre – plus fort que les antécédents de brûlure, l'exposition au soleil ou le type de peau – était la présence de taupes sur les bras (ouf, pas moi).

Alors que l'on nous dit que les taux de mélanome chez les jeunes Australiens ont commencé à baisser, Green a été l'un des auteurs d'une étude de 20 ans, publiée en avril, qui a montré que les taux de mélanome dans le Queensland étaient en augmentation dans tous les groupes d'âge. Cela semblait extraordinaire – aujourd'hui, les jeunes adultes contractent plus de mélanomes que lorsque ma cohorte avait leur âge. Le taux de mortalité par mélanome a toutefois chuté. Les jeunes adultes sont 81% moins susceptibles de mourir de cette maladie aujourd'hui qu'au début des années 1980. Green dit qu'ils comptaient les mélanomes in situ, le petit stade précoce du cancer qui ne s'est pas encore propagé. Le taux de mélanomes in situ a fortement augmenté dans cette génération ombragée. La statistique sur la baisse des taux de mélanome chez les jeunes concerne le mélanome "invasif". Green explique que tout dépend de la sensibilisation et du dépistage.

"Plus vous recherchez des mélanomes, plus vous en trouvez en raison de la vaste mer de taupes … Comme vous pouvez l'imaginer, il existe une gamme de taupes qui vont de la normale au drole, et certaines d'entre elles peuvent être assez risquées." La technologie récupère plus de ces taupes atypiques et les appelle mélanome que ce n’aurait été le cas par le passé, explique-t-elle, d’où une incidence accrue, et elle attrape aussi les mélanomes invasifs beaucoup plus tôt, sauvant des vies. Cela pourrait également expliquer pourquoi le taux de mortalité en Norvège est presque identique au nôtre. Ils ne sont tout simplement pas aussi vigilants.

Quand je passe du temps à Green, qui pense que rester à l'abri du soleil pourrait augmenter notre risque de maladies telles que la SEP, elle l'a écartée dans le contexte australien. "Si vous parliez du nord de la Norvège par rapport au sud de la Norvège, vous auriez peut-être quelque chose à dire. Pour un Queenslander, à la lumière du soleil, nous avons un tel indice ultraviolet énorme toute l'année, quiconque ne vit pas dans un cave va recevoir un minimum de rayons ultraviolets et de vitamine D, c'est du passé et il est convenu… Ensuite, si vous avez la peau sombre et que vous êtes à une latitude élevée – c'est là que la protection pourrait effectivement avoir un effet néfaste. . "

Qu'en est-il des avantages non-vitamine D? "Il y a beaucoup de travail dans ce domaine. Il y a de vagues études, mais rien n'a jamais été cloué … Dans ce pays, oui, vous pouvez avoir de très bons effets mentaux de l'ultraviolet, mais il n'y a pas beaucoup de choses où les gens peuvent disons que nous avons besoin de plus qu'un peu d'ultraviolet pour notre bien-être général. Mais je conteste ce que vous insinuez, qui est certainement publié dans la littérature avec certaines personnes qui disent que l'ultraviolet est tout bon et pas mal. Je dis que trop les rayons ultraviolets chez une personne à la peau claire sont nocifs, sans protection…

"Quand les gens commencent à parler de la protection solaire en supprimant les avantages de l'ultraviolet, je les mets au défi de proposer tout élément de fond cohérent, solide et biologique, pour le prouver."

Craig Sinclair du Cancer Council Victoria rappelle la période d'il y a 10 ans, lorsque cette organisation avait commencé à se faire critiquer pour son opposition farouche à la lumière du soleil. "Il y a eu une période où la vitamine D avait été créée pour sauver tous les maux, et beaucoup critiquaient notre message SunSmart, affirmant qu'il était allé trop loin. Nous étions évidemment inquiets à ce sujet. Nous n'avions jamais confronté à une situation, à l’exception du secteur des solariums, où les gens critiquaient notre marque établie de longue date et réputée pour sa confiance. "

La solution de Sinclair était de réunir Ostéoporose Australie, la Société australienne d’os et minéraux, la Société endocrinienne d’Australie et le Collège australasien des dermatologues dans une pièce avec le Conseil de lutte contre le cancer et de trouver un terrain d’entente. Ils ont trouvé la solution voulant que, lorsque l'indice UV dépassait trois, il était temps de se dissimuler. Et quand il y en avait moins de trois – dans les États du Sud, c'est tout l'hiver, tôt le matin et tard l'après-midi en été – il était temps de prendre un peu de soleil. Le Conseil du cancer dispose d'une application SunSmart que vous pouvez personnaliser en fonction de votre type de peau et de son emplacement. Il vous indique quand vous devez vous couvrir chaque jour pour vous conformer aux nouvelles directives.

Je l'ai téléchargé, mais je n'ai jamais eu le temps de l'utiliser. Parce que le message que j'ai retenu de tout cela ne semble pas si compliqué. Connais ta peau. Sortez au soleil, mais respectez-le comme le dieu qu'il a souvent été perçu. Ne pas brûler.

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