Sunscreen Not So Good for You? 616
j-beda writes "Don't like sunscreen? Maybe that tan is good for you. It looks like people are rethinking the common wisdom of avoiding sun exposure... "research suggests that vitamin D might help prevent 30 deaths for each one caused by skin cancer". Maybe if Kurt Vonnegut ever does address MIT grads, he will say something else..."
Kurt Vonnegut (Score:3, Informative)
Depends where you live (Score:5, Informative)
Re:Kurt Vonnegut (Score:2, Informative)
It's been said before (Score:5, Informative)
alternate vitamin D sources (Score:4, Informative)
Skin Cancer Kills (Score:5, Informative)
You *should* wear sunscreen... (Score:5, Informative)
Re:This is news? (Score:5, Informative)
If you bothered to read the article, you would be aware that there are different forms of vitamin D, and that most pills contain a different form than that produced by sunbathing (and also not very much of it).
It also noted that excessive vitamin D from pills can lead to a build-up of calcium in the body (not a good thing), which is not an issue with sunbathing.
Vitamin pills shouldn't be necessary at all - if you need them, then there's something wrong with your diet and/or lifestyle.
Re:Common sense (Score:4, Informative)
Re:You *should* wear sunscreen... (Score:2, Informative)
Drink milk. (Score:1, Informative)
Re:alternate vitamin D sources (Score:4, Informative)
Another guy sacked for his opinion (Score:2, Informative)
Re:alternate vitamin D sources (Score:2, Informative)
tainted with heavy metals and chemicals they pick up...
http://www.usnews.com/usnews/health/articles/0303
this article has an entire chart on levels of metals in different types of fish
http://www.thegreenguide.com/doc.mhtml?i=103&s=fi
of course it's not good for me (Score:2, Informative)
Re:Not in Australia (Score:3, Informative)
Here in Finland we get very little sun in winter. Leder of National Institue of Health in Finland said last winter that it would be cheaper to pay one week middle winter vacation in Spain for all finns than pay for the treatment of disases that come from lack of vitamin D. That is big amount of money.
[1] from the article:
Re:The answer, like almost every argument on healt (Score:3, Informative)
The lux (symbol: lx) is the SI derived unit of illuminance or illumination. It is equal to one lumen per square metre.
Re: Lancet nails the real cause of cancer (Score:5, Informative)
"In many [western] countries, peoples' diet changed substantially in the second half of the twentieth century, generally with increases in consumption of meat, dairy products, vegetable oils, fruit juice, and alcoholic beverages, and decreases in consumption of starchy staple foods such as bread, potatoes, rice, and maize flour. Other aspects of lifestyle also changed, notably, large reductions in physical activity and large increases in the prevalence of obesity."[18]
"It was noted in the 1970s that people in many western countries had diets high in animal products, fat, and sugar, and high rates of cancers of the colorectum, breast, prostate, endometrium, and lung; by contrast, individuals in developing countries usually had diets that were based on one or two starchy staple foods, with low intakes of animal products, fat, and sugar, and low rates of these cancers."[18]
"These observations suggest that the diets [or lifestyle] of different populations might partly determine their rates of cancer, and the basis for this hypothesis was strengthened by results of studies showing that people who migrate from one country to another generally acquire the cancer rates of the new host country, suggesting that environmental [or lifestyle factors] rather than genetic factors are the key determinants of the international variation in cancer rates."[18]
See also:
Scientists estimate that most cancers are associated with factors related to how we live, called lifestyle factors. Evidence reviewed by the American Cancer Society suggests that about one-third of the 550,000 cancer deaths that occur in the United States each year is due to dietary factors (for example, excess calories, high fat, and low fibre). Another third is due to cigarette smoking. Other lifestyle factors which increase the risk for cancer include drinking heavily, lack of regular physical exercise, promiscuous sexual behavior,
Re:Another guy sacked for his opinion (Score:3, Informative)
Re:Depends where you live (Score:1, Informative)
(1) Altitude - UV increases 4% for 300 meters of altitude. Modifier = ~1.2x
(2) Frequent snow (obviously only ~5 months of the year) - Snow can reflect 90% of UV, scattering upwards. Modifier = ~1.9x
Winter exposure factor: 1.2 * 1.9 = ~2.2 times the UV exposure as at sea level (we typically get snowfall overnight then the days have brilliantly clear blue skies).
Sand reflects 25% of UV, so summer exposure would be: 1.2 * 1.25 = ~1.5 times the UV as at sea level.
Anyway, the upshot of this is that you burn like crazy if you're not careful skiing - and I can catch a noticable tan just driving 20 minutes to work with the sunroof open (then I lurk inside all day doing computery stuff).
(FYI, I took those numbers from this page [kjc.gov.my], found via a google search for "uv at altitude").
Re:Bullshit Health "Science" (Score:5, Informative)
Science is about repeatable controlled experiments that yield consistent results. Repeatable means that you need to understand what exactly is going on in your experimental setup so that somebody else can reproduce it. Controlled means you account for all variables and only vary one at a time.
The problem is that doing all this correctly with people costs a LOT of money. So, instead we settle for sloppy studies that aren't well-controlled, then everybody starts talking about how useless science is when five people do the "same" study and come up with different conclusions. Some of the common flaws:
The only really effective way to these kinds of tests on people is with placebo-controlled clinical trials. Take 2000 people, split them into a few groups which are as similar as possible in makeup, and make them all spend 15 minutes a day blindfolded in a tanning booth, and make them all take pills. Some groups don't actually get any UV, but the experience is simulated so that they don't realize this. Some groups do get the UV. Some groups get various vitamin D supplements (with or without vitamin A), and some groups get placebos. At least one group gets neither UV or a supplement. Then follow the group over 50 years and see what the results are. Such an experiment should be both conclusive and repeatable.
Of course, most scientists want their results next year and have limited budgets, so they're not going to start a 50-year study that they won't even be alive to see the end of. Instead, they just look at random dead people and try to guess how much time they spent in the sun and what pills they have taken.
Even modern drug clinical trials have all kinds of issues (clearly seen in recent high-profile drug recalls) - these trials are very carefully controlled trials subject to all kinds of review and which cost hundreds of millions of dollars to perform.
So, the problem isn't a failure in science. The problem is that sometimes we aren't patient enough or resourceful enough to use science, and instead resort to something else and call it "science". Science isn't very practical when dealing with people - they live a long time, you can't just put them in cages, you have to pay them, and you can't do much in the way of manipulating them. Most real biological science uses other animals as a result (Need some subjects with cancer? Just breed them to be prone to it.)...
Re:Bullshit Health "Science" (Score:3, Informative)
Hey, you're right. I'm giving up my granola bar snack and going to eat dog shit instead. It's much more natural and less refined. If I can't find dog shit I might try a scoop of mud. OK, I'm carrying it too far. In reality I'll just eat more natural vegetables like rhubarb. It can't possibly be harmful [tamu.edu] to me because it's natural.
Re:Drink milk. (Score:3, Informative)
We also eat honey, which is for bees, not humans. And meat, which is for tigers, not humans. And fish, which is for bears, not humans. And plants, which are for cows, not humans.
It's kind of silly to worry about whether the food you're eating is "for" something other than you. All that matters is what it's made of, and cow's milk contains essentially the same stuff as human milk, but in different proportions.
BTW, what are "traces of gm"? General Motors? General Mills? General MacArthur? Surely you realize that genetic modification is not something that can be passed from one organism to another through eating.
Re:Common sense (Score:5, Informative)
Re:Not in Australia (Score:5, Informative)
It's the latitude. Boston is around 42 N. Australia is mostly between 16 S (Cairns) and 34 S (Sydney). In the northern hemisphere, you should be comparing yourself to somewhere in Mexico or North Africa, not the northern USA.
Re:Kurt Vonnegut (Score:5, Informative)
Re:Bullshit Health "Science" (Score:3, Informative)
That's good advice, and not too far off from the generally accepted 5 "pillars" of healthy living: Eat healthy (5 balanced, small meals a day), drink plenty of water, get enough sleep, do some weight training and some cardio exercise.
Cardio exercise alone is not enough. Walking/running/whatever will burn off calories, but doesn't build bone or muscle density. If osteoporosis runs in your family, then you should pay extra attention to getting enough protein and calcium, and doing some light weight training a couple times a week.
As an aside, is it true that vitamin D can only be obtained by sunlight? My wife and I buy milk that claims to be "Vitamin A and D enriched" - is that not possible?
It comes down to moderation in the end (Score:1, Informative)
I work in a cancer registry (in IT, not research), and I can tell you that no-one's entirely certain about the pros and cons of sun use yet. The general advice is this:
When young, your skin is especially vulnerable to damage from the sun, damage that can lead to melanoma (not plain old non-melanoma skin cancer, but the full, fatal whack) in later life.
Once you reach your twenties you skin is a bit more resilient to this damage. Meanwhile you begin to fall into the age-group where you may be affected by cancers that might be prevented or deterred by vitamin D. So a little sunlight is a good thing.
Note, that's a little sunlight. Spending all day out in the sun crisping yourself is not going to end well. As with everything in life, moderation is the key. Further, if you live in a an area where the sun is particularly strong (Australia, South South America, etc.), you should still be careful.
Re:Uhm (Score:5, Informative)
Re:Common sense (Score:3, Informative)
Re:Common sense (Score:5, Informative)
Re:Got Milk? (Score:5, Informative)
Just buying it might not be enough. You might want to take the next step and drink it as well.
The real debate underlying this article surrounds the appropriate "dose" of vitamin D. The current recommendations in the US (400 IU per day) are entirely based on requirements for maintaining normal bone mineral composition. This has absolutely no relation to other biological effects of vitamin D (cellular differentiation, immune cell activity).
Whereas you can get 400 IU per day by drinking vitamin D fortified milk, full-body exposure to solar ultraviolet radiation can produce as much as 10,000 - 40,000 IU of vitamin D. In the winter and at high latitudes vitamin D production from solar UV can drop to zero. Between diet, supplements, and sun exposure, the ideal combination and target dose for cancer prevention has not been established. It is almost certainly considerably above the 400 IU that you need to maintain healthy bones.
so you're the scientific authority? (Score:5, Informative)
1) Milk ISN'T good for you, period, [sic]
Actually, it all depends on who you mean by "you," and what your underlying assumptions are about resources, technology, etc. If you are lactose intolerant, then by all means stay away from milk. That doesn't mean you can't have cheese and yogurt, though. It is a well-accepted theory that the lactose tolerance mutation of northern European populations is one of the factors that enabled their success (and by success, I mean they didn't all die out). It is also true that Mongolian tribesmen may not have the resources to eat fresh kale to get their calcium, or to buy soy "milk" from their local organic grocery store. However, goats, sheep, and cows can digest grasses and produce milk with--guess what--calcium! But in fact, it's the casein in milk that supplies the protein, and many vegetarian cultures have relied on dairy products for a large part of their protein consumption.
2) humans weren't supposed to drink another animals milk [sic]
You should be careful when using words like "supposed" because you imply you have some sort of insight into the Way the Universe Should Be. Bullshit. You can't say humans weren't supposed to drink milk anymore than you can say humans weren't meant to jump rope. No other animal does that, either. No other animal writes poetry, or commits suicide, or contemplates philosophy. Just because humans differ from other animals does NOT imply any should or ought, so shut your mouth unless you have some Divine Insight. I would like to point out that other animals may not drink milk after infancy, but they do eat organ meat, entrails, eyeballs, and all sorts of other nutrient-rich animal parts that we tend to discard, these days--including partially digested food in the animal's intestinal tract. Maybe you'd prefer eating tripe to drinking milk?
3) This is ignoring the pitfalls falls of todays production techniques whereby they pump growth hormones into the cows so they produce milk far longer than they are normally capable of. [sic]
This is your single valid point, and it is only valid for milk from a regular dairy. Those same organic grocery stores that sell soy milk also sell milk from cows without all those hormones and (though you didn't mention it) antibiotics. But you're tangling the issues, here. That is an argument for better treatment of dairy cattle, not an argument against milk itself. I have a problem eating hot dogs, these days, but that doesn't make all meat repulsive to me.
Maybe someday it will be proven that milk is the poison you make it out to be. But now, the evidence is far from conclusive, and you obviously don't know your milk history. As it stands, milk was probably responsible for my ancestors' survival, and your burden of proof is pretty high. Oh, and a better grasp of English grammar and spelling might help you be more persuasive, in the future. It would be comical that you have a sentence "Milk ISN'T good for you period," ending in a comma, except that I'm pretty sure you didn't intend that.
Re:Kurt Vonnegut (Score:5, Informative)
In late May 1997, Chicago Tribune metro columnist (and "Brenda Starr" writer) Mary Schmich was walking to work along Lake Shore Drive, wondering what she was going to write about that day. It occurred to her that it was near graduation time and she thought she would write a column that read like a commencement address. As she wondered what advice she might offer, she saw a woman sunbathing on the shore of Lake Michigan.
"I hope she's wearing sunscreen," thought Schmich, 45, "because I didn't at that age."
And that's how newspaper columns are born.
A couple of months later, the column became an Internet hoax when a prankster - never identified except as "Culprit Zero" - copied it, labeled it as "Kurt Vonnegut's commencement address at MIT,"
Re:Common sense (Score:4, Informative)
This is why it's foolish to watch food cholesterol content more closely than fat, which is the source of the rest of the cholesterol.
Re:Not in Australia (Score:3, Informative)
The fact that the summer sun is brighter in Australia than at a similar northern latitude at the equivalent time of year has an effect (do you know how large? A quick google search didn't tell me), but I'd guess it's on the order of moving a few degrees closer to the equator, not as big as the difference in latitude between Sydney and Boston.
Melanoma vs. Carcinoma (Score:3, Informative)
Melanoma is deadly. Carcinoma is not something you want, but is generally not life-threatening.
There's a very strong positive correlation between sunlight exposure and Carcinoma. Not so melanoma.
A recent large study showed an inverse correlation between sunlight exposure and melanoma. Previous studies showed weak positive, or grouped all skin cancers together.
I don't think that anybody argues that skin-peeling burns are bad for you, but many experts are moderating previous advocacy of total sun-avoidance.
Re:alternate vitamin D sources (Score:3, Informative)
Except that fish contain high levels of mercury which is also pretty serious. [bbc.co.uk]
Damien
Re:Common sense (Score:4, Informative)
Whoever modded this as troll was a bit lacking in basic biology.
Pretty much every mammal is lactose intolerant, and is only able to stomach the stuff during infancy. They lose lactose tolerance shortly after infancy. Some infants are lactose intolerant, and this used to be a big problem with finding some other source of food for baby.
The fact that most Europeans have lactose tolerance is a selected trait. Most other humans are not tolerant to lactose. And even those of us who are tolerant to lactose are only so up to a point. Your body can only produce so much lactase to break down lactose before it gets overwhelmed and has to let it all through, as many people who have drunk an entire gallon of milk in about 10 to 20 minutes without taking a lactase enzyme suppliment can tell you.
Re:so you're the scientific authority? (Score:3, Informative)
3) This is ignoring the pitfalls falls of todays production techniques whereby they pump growth hormones into the cows so they produce milk far longer than they are normally capable of. [sic]
This is your single valid point, and it is only valid for milk from a regular dairy.
I wouldn't use the term 'valid'. As the son of a farmer, I know our farm never used rBST (growth hormone) and all the other farms that sold to our coop pledged not to use it either. *If* they found you were using rBST, the very minimum that would happen is this: The farmer that used the rBST would have to buy all the milk in the milk silo their milk was put into. We're talking millions of gallons of milk. Enough to bankrupt most any farm. I won't even go into the legal implications.
Losing a million dollar business is quite a disincentive to use something that'll squeeze a couple more gallons out of the cows.
Re:The dose makes the poison (Score:4, Informative)
If you have healthy endocrine system, kidneys and heart, and are eating right, it's almost impossible to do it when you DRINK water (I say almost because there is always be that one extra determined person). The real problem with water intoxication happens in hospitals when we start using iv fluids. In this setting it's pretty easy to muck up someone's hydroelectrolytic balance within a few hours and push them into a coma, or worse.
The majority of you are probably not even drinking near enough water.
The body is quite good at determining how much water it needs. Thirst is the best indicator of how much you should drink. It's never wrong. Like the man says, "obey your thirst".
There is an argument that people who drink "pop" are chronically dehydrated because of all that sugar upsetting the "osmotic balance" of the body. What they forget is that the body metabolizes glucose FIRST.
The metabolism of glucose actually PRODUCES water as well (empirically: C6H1206 + 602 --> 6CO2 + 6H2O). Any excess glucose is quickly turned to glycogen (non soluble and intracellular) and fat (also does not affect the osmotic balance since it's not soluble). The synthesis of these storage molecules ALSO produces water (they are condensation reactions). So that's another urban legend out the window. Otherwise people would die just by eating.
The only thing drinking pop all the time will do is make you fat, which increases your risk of type II diabetes, and THEN you will end up with osmotic problems. This is because of the pathology causing your blood glucose (and other things) to skyrocket, but that's a whole other kettle of fish...
Re:so you're the scientific authority? (Score:2, Informative)
I shop at a regular grocery store, and actually finding non-BST milk from the big distributers is no problem. Just look for it on the label ("Not treated with rBST/rBGH"), and they're usually right next to each other from the same milk distributers. They come in the same cartons, are just as common on the shelf as the other kind, and even cost the same, iirc. I buy it all the time.
Re:so you're the scientific authority? (Score:3, Informative)
That's probably why they say ``not treated with
http://www.notmilk.com/ [notmilk.com]
Re:so you're the scientific authority? (Score:4, Informative)
Since BST is a peptide, it gets digested with all the other proteins and peptides in milk, and has bugger all effect. After all, if peptides with hormone activity could be so easily absorbed from oral ingestion, it would make diabetics lives a lot easier - but no, insulin gets digested, so they have to bypass the gut with injections.
Re:Uhm (Score:1, Informative)
Re:Bullshit Health "Science" (Score:3, Informative)
Sean
Re:so you're the scientific authority? (Score:5, Informative)
15 minutes of sun every 2 weeks (Score:3, Informative)
Re:Common sense (Score:3, Informative)
The Europeans were the first to have global colonies.
The Europeans tamed the mighty continent of Africa in terms of agriculture (and had to give it back to the warlords only to be put back in poverty)
The Europeans came to and populated most of America and that culture is what got us to the moon.
Nah, you should still say the Chinese.
1. While there is evidence pointing to a Chinese map that included North American pre-1500s, it is controversial evidence so I'll give you that one.
2 and 3. China at one point had an empire that stretched from the China Sea to the Danube River in Europe [wikipedia.org]. Conquering the mighty continent of Asia is a bit more impressive than Africa. Of course this vast empire was only held for a couple generations before splitting into sub-states.
4. China didn't populate America and didn't get to the moon; BUT China (random sampling from Genius of China - DS721
Used quantitative cartography (grid mapmaking): AD 200s
Recognized solar wind: AD 600s - an explanation for comet tails always pointing away from the sun
Transported and burned natural gas - 400s BC : "...they use bamboo tubes to 'contain the light', conserving it so that it can be made to travel from one place to another, as much as a day's journey away from the well without its being extinguished. When it has burnt no ash is left, and it blazes brilliantly."
Deep drilled for natural gas - AD 100s; their techniques for drilling were imported into Europe in the 1800s
Invented matches: AD 557
Mechanical clock: AD 800s
Moveable type printing: 1200s
Gunpowder: AD 900s
Explosive weapons: AD 900s - grenades, mines, bombs, etc.
Rockets: AD 1200s - "bees' nest" rocket launchers that launched over 300 rockets at a time must have
been devastating.
The iron plow (since we are kind of talking about agricultural influence): 600s BC.
The efficient horse harness: 300s BC - the trace harness found its way into Europe via Central Asia. The Avars invaded Hungary in 568 AD and brought the harness back with them; they also imported the stirrup.
Re:All depends on time of day and where you live (Score:2, Informative)
Australia does have increased risk factors including neing near to the ozone hole [theozonehole.com] over the Antarctic.
Australians suffer the highest rates of skin cancer in the world. Each year, around 1,200 Australians die from what is an almost totally preventable disease. Everyone can develop skin cancer; however, some people may be at higher risk than others, due to a range of factors.
Australia exposed to more UV
Ultraviolet (UV) radiation levels in Australia are higher than in Europe, even during summer. Being located close to the ozone hole over the Antarctic means much higher, more severe levels of UV radiation get through to ground level.
During summer, the earth's orbit brings Australia closer to the sun than Europe during its summer, resulting in an additional seven per cent solar UV intensity. This, coupled with our clearer atmospheric conditions, means Australians are exposed to up to 15 per cent more UV than Europeans.
are sunscreen active ingredients safe? (Score:1, Informative)
See if you can find a single study showing that the active ingredients of most sunscreens are safe when absorbed through the skin into the bloodstream.
Refs:
Sunscreen ingredients are absorbed into the blood:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd
Sunscreen ingredients cause DNA damage:
http://www.blackwell-synergy.com/links/doi/10.104
this site thinks sunscreen use makes people gay? (Score:1, Informative)
http://www.skinbiology.com/toxicsunscreens.html [skinbiology.com]
Admittedly, it's a commercial site that would like you to buy their supposedly safe products, but they could be right in what they say.
--
Sunscreen chemicals may generate free radicals within your body
Most chemical sunscreens contain, as UVA and UVB blockers, from 2 to 5% of compounds such avobenzone, benzophenone, ethylhexyl p-methoxycinnimate, 2-ethylhexyl salicylate, homosalate, octyl methoxycinnamate, oxybenzone (benzophenone-3) as the active ingredients.Benzophenone (and similar compounds) is one of the most powerful free radical generators known. It is used in industrial processes as a free radical generator to initiate chemical reactions. Benzophenone is activated by ultraviolet light energy that breaks benzophenone's double bond to produce two free radical sites. The free radicals then react with other molecules and produce damage to the fats, proteins, and DNA of the cells - the types of damage that produce skin aging and the development of cancer.
Adding to the problem is that large amounts of applied sunscreens can enter the bloodstream though your skin. In the 1970s, Prof. Howard Maibach warned that up to 35 percent of sunscreen applied to the skin can pass through the skin and enter the bloodstream but this had little effect on sunscreen promotion or safety testing. (Maibach, H. "NDELA-Percutaneous Penetration." FDA Contract 223-75-2340, May 19, 1978) The longer sunscreen chemicals are left on the skin, the greater the absorption into the body. (Bronaugh, R.L., et al. "The effect of cosmetic vehicles on the penetration of N-nitrosodiethanolamine through excised human skin, J Invest Dermatol; 1981; 76(2): 94-96.) This may be a factor in the large increases in cancer (breast, uterine, colon, prostate) observed in regions, such as Northern Australia, where the use of sunscreen chemicals has been heavily promoted by medical groups and the local governments.
Many sunscreens also contain triethanolamine, a compound that can cause the formation of cancer causing nitrosamines in products by combining with nitrite used as preservative and often not disclosed on sunscreen labels.
In March 1998, Dr. John Knowland of the University of Oxford reported studies showing that certain sunscreens containing PABA and its derivatives can damage DNA, at least in the test tube experiments. When a chemical sunscreen, Padimate-O, was added to DNA and the mixture exposed to the ultraviolet rays of sunlight, it was found that the sunscreen broke down in sunlight, releasing highly active agents that could damage DNA. It did not block out the UV, but instead absorbed energy. "It became excited and set off a chemical reaction that resulted in the generation of the dangerous free radicals and broken DNA strands that can lead to cancer," he said and further commented that while it's too early to make blanket recommendations, "I would not use a product containing PABA, Padimate-O or other PABA derivatives." Dr. Martin Rieger reported that PABA may play a role in DNA-dimer formation, a type of DNA damage that can induce carcinogenic changes.
Avobenzone (Parsol 1789) May Not Be Safe Either
In 1997, Europe, Canada, and Australia changed sunscreens to use three specific active sunscreen ingredients - avobenzone (also known as Parsol 1789), titanium dioxide, and zinc oxide - as the basis of sunscreens. In the USA, the cosmetic companies have held off this policy as they try to sell off their stockpiles of cosmetics containing toxic sunscreens banned in other countries.
However, avobenzone is a powerful free radical generator and also should have been banned. Avobenzone is easily absorbed through the epidermis and is still a chemical that absorbs ultraviolet radiation energy. Since it cannot destroy this energy, it has to convert the light energy into chemical energy, which