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| NaturistDoc |
Posted - 07/24/2006 : 9:12:22 PM
(I normally don't send out annoying 'informative' posts, but I'm making an exception this time, since sunscreens are of particular interest to naked people. Apologies for the length and technical jargon.)
I was mildly interested to read today that the FDA has given its approval for the sale in the U.S. of sunscreen containing an ingredient called Mexoryl. However, when I delved a little deeper into the background of the story, I was flabbergasted. Mexoryl is by all accounts a huge improvement over what is currently available here. American dermatologists have been screaming for this stuff for years. Here's why.
The sunscreens we used when we were kids only blocked UVB rays (290-320 nm). These rays are the ones that cause sunburn, and until the late 1970's, they were thought to be the only 'dangerous' part of the solar UV spectrum.
UVA radiation (320-400), having a longer wavelength and therefore lower energy than UVB, didn't attract much attention until dermatologists noticed that sunscreen use, while preventing sunburn, didn't seem to be protecting people from skin cancers or from skin damage like wrinkles and loss of elasticity. It turned out that UVA penetrates much farther into the skin than UVB, and is actually more dangerous in the long run than UVB.
Several "UVA blockers" have been developed and marketed in the U.S., but none of them is particularly good, especially at the longer wavelengths. Oxybenzone and avobenzone absorb some (not all) UVA, but are destroyed in the process and lose effectiveness in a short time. The only things that really work are zinc oxide and titanium oxide, which are pasty white goops that nobody wants to use
Mexoryl was developed in France in the 1980's. Unlike the 'benzones', it isn't destroyed by UVA rays. It blocks all UVA wavelengths, but not all UVB, so it's usually mixed with a UVB blocker.It is the consensus choice of dermatological societies all over there world. Other than bureaucratic inefficiency, I don't know why the FDA has delayed approval of Mexoryl. Maybe because it's French. [Conspiracy theorists claim it's to protect Neutrogena/Johnson & Johnson. They are bringing to market a UVA blocker called Helioplex, which is essentially a stabilized form of avobenzone Hmmm.] L'Oreal will market Mexoryl under the trade name Anthelios. The problem is, it won't be available until the summer months have come and gone, and will initially be sold only as SPF 15.
The good news is that these sunscreens (up to SPF 60) are available online from Canadian pharmacies. The not-quite-so-good news is that the FDA regards importing them as technically illegal, although I doubt you'd get a prison sentence for contraband sunscreen. They're also kinda pricey; we're talking L'Oreal, after all. But you're worth it. |
| 15 L A T E S T R E P L I E S (Newest First) |
| calgarymark |
Posted - 05/27/2021 : 3:18:33 PM
I couldn't find a suitable thread for this item; this one seemed the most suitable, if a naturist can use that term. This is mainly about the benefits of sunshine and Vitamin D.
Dr Roger Gillie was a British journalist who wrote extensively about the benefits of sunlight and Vitamin D. We know what that means for good health and a sense of well-being (as well as no tan lines). I just searched for Roger on DuckDuckGo (I refuse to use Google) and found an updated Wikipedia entry for him:
https://en.wikipedia.org/wiki/Oliver_Gillie
He died on 15 May 2021. Somebody updated the entry just a couple of days ago. The entry references an extensive obituary in the Guardian https://www.theguardian.com/society/2021/may/21/oliver-gillie-obituary
I crossed paths with Oliver at high school in the late 1950s and read many of his newspaper articles in the 1960s before I emigrated to Canada. I recommend that you study his paper ‘Sunlight Robbery’, which you can download at https://www.healthresearchforum.org.uk/oliver.html
RIP, Roger.
CalgaryMark
"Life's too short to be taken seriously".
"Be yourself - everyone else is taken". Attributed to Oscar Wilde. |
| NaturistDoc |
Posted - 03/05/2020 : 02:47:18 AM
At last! At long last Dr. Weller's study has been published, and it is indeed large, involving some 342,457 patients. It asks (and purports to answer) the question, "Does Incident Solar Ultraviolet Radiation Lower Blood Pressure?" The article has already found its way into the mass media via, once again, 'Outside' magazine. His answer is, of course, "Yes", but I'm not at all sure I agree.
Weller et al rather astutely used a database of kidney dialysis patients, since these folks get their blood pressure measured very frequently at dialysis centers by trained personnel who know how to work a blood pressure cuff. But one could reasonably ask if kidney failure patients are a fair representation of the population at large. That is only one of the problems I have with Dr. Weller's paper.
First let's look at the overall results, shown in Figure 3. Systolic blood pressure (the "top number") declines from a little under 150 to a little over 147 with increases in temperature, UVA exposure, and UVB exposure. A decline of less than 3 mmHg may be statistically significant, but is it clinically or physiologically relevant? Maybe, maybe not. But there are other problems. First of all, seasonal variation in blood pressure have been known for decades, and have largely been attributed to temperature: warmth causes vasodilation while cold causes vasoconstriction. Obviously, solar UV radiation will go up along with temperature as winter turns to summer. Weller claims to show that UV exposure decreases systolic blood pressure in a manner independent of temperature, but if you read carefully you'll see that the patients' level of UV exposure is never actually measured, but rather estimated from a computer model run by the National Center for Atmospheric research. As the authors concede, "[s]ince it was not feasible to determine personal exposures to UV radiation and temperature, we approximated these exposures using environmental data retrieved from public databases at matched locations." My guess is that people with end-stage kidney failure probably don't get out as much as the rest of us, drawing the applicability of the data to the general population into question. The authors also state that ".[w]e analyzed systolic rather than diastolic BP as in dialysis patients the former is associated with patient outcomes." Yet the reference they cite clearly indicates that systolic blood pressure measurements taken in dialysis centers did NOT correlate with mortality. My last objection is that they claim that solar UV lowers blood pressure independently of temperature, while at the same time writing "[a]s expected, incident UV radiation and environmental temperature were closely associated." The complicated statistical gymnastics they use to tease out the separate effects of temperature and solar UV exposure seem suspect to me, although I concede I am no genius when it comes to statistics.
To be clear, Weller et al MAY be correct in stating that the UV radiation in sunlight, by itself and independently of temperature, causes a decrease in systolic blood pressure. I don't believe they're proven their caae, and at best the contribution of UV radiation to the overall seasonal variability in blood pressure, if it exists at all, is very small. My general reaction is "Meh."
https://www.ahajournals.org/doi/10.1161/JAHA.119.013837 |
| NaturistDoc |
Posted - 01/23/2020 : 5:43:22 PM
A year on, Dr. Weller's "largest study yet" (see above) still hasn't been published. He did publish an article in November 2019, but it was an in vitro/ex vivo study that did not involve actual human subjects. If you're interested, here it is.
https://www.sciencedirect.com/science/article/pii/S1089860319302721?via%3Dihub
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| NaturistDoc |
Posted - 01/23/2020 : 5:14:44 PM
If you find it curious that the FDA recommends an identical limit of 0.5 ng/ml for half a dozen totally different chemicals, I do too. Clearly it isn't based on empirical data, and is most likely an example of the Precautionary Principle, which Wikipedia defines as "a strategy for approaching issues of potential harm **when extensive scientific knowledge on the matter is lacking**". There is ZERO evidence that exceeding the 0.5 ng/ml threshold for any of these sunscreens is harmful. The only one that concerns me is oxybenzone, which does appear to have MUCH higher systemic absorption than any of the others. Some (not all) manufacturers are replacing oxybenzone with the (presumably) safer avobenzone
Here is a somewhat better analysis of the JAMA study cited by the Daily Mail
https://www.medpagetoday.com/dermatology/generaldermatology/84459?xid=fb_o&trw=no&fbclid=IwAR1RvxBnbZDQ6pl9FdZbJvAuBZePLBYktQ1He9hAMMXabd6TH3RH0br3oYA
Now, do I believe that chemical sunscreens are 100% safe? No. (PABA definitely wasn't.) But neither do I think that blood levels exceeding some arbitrary recommendation are necessarily dangerous. Given the enormous number of people who have used these sunscreens for years if not decades, you'd think that if they caused serious harm, some evidence would have come to light by now. But i will happily welcome more research. Personally, I avoid products with oxybenzone. If you're really worried about the safety of these sunscreens, there are dozens of 'mineral sunscreens' available ... if you can stand them. |
| Bill Bowser |
Posted - 01/22/2020 : 8:37:10 PM
Being skeptical of anything you read on the internet is wise, but some of it is worthwhile. Differentiating is difficult.
Bill Bowser - Cincinnati
Not lewd, not crude, just nude.
Nudists are everywhere, but they're hard to identify with their clothes on. |
| calgarymark |
Posted - 01/22/2020 : 8:22:01 PM
I'm suspicious of anything in a UK tabloid newspaper (or e-edition), but at least they cite sources. NaturistDoc: Comments?
CalgaryMark
Growing old is mandatory, Growing up is optional. Laughing at yourself is therapeutic. |
| Bill Bowser |
Posted - 01/21/2020 : 8:58:06 PM
An article in the UK Daily Mail describes a study which found that sunscreens leach up to 360 times more toxic chemicals into the blood than the FDA allows, raising risks for liver and kidney failure. The effects of these chemicals is probably not as alarming as the news media would have you believe, but it is something to think about.
The article is here: https://www.dailymail.co.uk/health/article-7911979/Sunscreen-chemicals-concentrations-blood-360-TIMES-higher-FDA-threshold.html
Bill Bowser - Cincinnati
Not lewd, not crude, just nude.
Nudists are everywhere, but they're hard to identify with their clothes on. |
| NaturistDoc |
Posted - 06/01/2019 : 03:04:16 AM
Update: As of June 1, Dr. Richard Weller has still not published "his largest study yet" mentioned in the article cited in my post of 1/14/2019. However, I have other things to report.
First, contrary to the Outside article and Dr. Weller's TED talk, Dr. Weller's own published research demonstrated no significant effect, beneficial or otherwise, of UV-A exposure on blood pressure.
www.ncbi.nlm.nih.gov/pmc/articles/PMC5959980/
The lack of persuasive evidence has not stopped Dr. Weller from forming a start-up company called RelaxSol which intends to market "Dr. Weller's Sunwell Sunscreen". (Their slogan: "Safely draw the goodness from the sun.") It will supposedly be available in the UK any day now. Unfortunately, the website does not offer a list of ingredients.
www.drwellerssunwell.com
To be fair ... Dr. Weller has a somewhat plausible rationale for his notion that sun exposure might lower blood pressure. Exposure of skin to UV-A radiation DOES seem to cause a transient increase in circulating nitric oxide, a substance known to dilate blood vessels. But nitric oxide has an extraordinarily short half-life - on the order of milliseconds - in the bloodstream, and as noted above, no significant changes in blood pressure were found. Who knows? Maybe he's right, and 'Dr. Weller's Sunwell' will be the greatest sunscreen ever. But nothing I've seen so far gives me the slightest reason to believe so.
"In God we trust. All others must bring data." -W. Edwards Deming
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| calgarymark |
Posted - 05/27/2019 : 1:35:59 PM
Further to the above, I checked Amazon.ca - there is a hardcover edition of the book mentioned in the review/news article. It would have to be imported from the UK and is priced at ~CAD$63 (US$47.00) The book addresses many more issues than Vitamin D (according to the summary in the Amazon write-up).
CalgaryMark
Growing old is mandatory, Growing up is optional. Laughing at yourself is therapeutic. |
| calgarymark |
Posted - 05/27/2019 : 1:15:31 PM
This article (which is more about the need for Vitamin D than sunscreens) just appeared in the Guardian online:
https://www.theguardian.com/society/2019/may/26/top-uk-scientist-urges-people-to-take-vitamin-d-supplements?CMP=share_btn_link
I could 'manufacture' a link that says 'get out in the sun for your health's sake, but use an effective sunscreen (if you can find one that doesn't do more harm than good  )'
CalgaryMark
Growing old is mandatory, Growing up is optional. Laughing at yourself is therapeutic. |
| NaturistDoc |
Posted - 05/18/2019 : 3:53:43 PM
Since the day I started this thread many years ago, I have never bothered to conceal my annoyance both with the foot-draggers at the FDA and the well-intentioned but misinformed nincompoops at the Environmental Working Group. The FDA, after an agonizingly slow process, grudgingly allowed "Anthelios", a low-SPF formulation containing Mexoryl (which has been sold in Europe and elsewhere for many years) onto the US market. It was a baby step in the right direction, but higher-SPF versions are still unavailable here. In the meantime, the EWG, reacting to in vitro studies of questionable relevance to the real world, decided that ALL chemical sunscreens were the work of the devil and should be avoided in favor of 'barrier' sunscreens containing zinc oxide or titanium oxide. Trouble is, barrier sunscreens range from merely unpleasant to downright disgusting in actual use. What's worse, Consumer Reports, whose opinions I value far more than the EWG's, found that barrier sunscreens were consistently less effective than chemical sunscreens.
Now the State of Hawaii, again relying on rather meager and questionably relevant research suggesting toxicity to corals, is banning the sale of sunscreens containing oxybenzone and/or octinoxate, which means most of the brands currently sold in the US. Related compounds such as avobenzone, octocrylene, and octosalate are still deemed "reef-friendly". Somewhat to my relief, my go-to sunscreen, a Canadian product called "Ombrelle", contains neither of the banned ingredients, nor is it one of the gooey and ineffective barrier types. Unfortunately it's not approved for sale in the US.
(A political aside: The world's coral reefs are indeed in trouble, due mainly to getting cooked by rising sea temperatures and poisoned by agricultural and industrial runoff. Focusing on the supposed risks posed by sunscreens while ignoring the bigger problems strikes me as a classic example of "re-arranging the deck chairs on the Titanic".)
The government of Sweden - home to a lot of very sun-sensitive people - has published a monograph on the science, such as it is, of the environmental toxicity of sunscreens. They take pains to point out the obvious: "There are concerns that experiments undertaken to date have been largely ex-situ, and mainly at subcellular, cellular and organism level, with very few studies of the wider impacts of sunscreens and their UV filters. There is a lack of firm evidence of widespread negative impacts at reef community and/or ecosystem level. The evidence available may not properly reflect conditions on the reef, where pollutants may rapidly disperse and be diluted. Concentrations of UV filters used in experimental work have generally been higher than those likely to be encountered in the reef environment, although no study has assessed the levels of these chemicals in the tissues of long-lived species."
https://www.icriforum.org/sites/default/files/ICRI_Sunscreen_0.pdf |
| Bill Bowser |
Posted - 05/14/2019 : 9:28:32 PM
This article in the UK Daily Mail indicates that the FDA isn’t interested in approving new, more effective sunscreens. Some have been awaiting approval for more than 30 years.
https://www.dailymail.co.uk/health/article-7025145/Why-sunscreen-better-Europe-EU-allows-27-UVA-blocking-ingredients.html
Bill Bowser - Cincinnati
Not lewd, not crude, just nude.
Nudists are everywhere, but they're hard to identify with their clothes on. |
| NaturistDoc |
Posted - 03/09/2019 : 10:11:06 PM
Neither a PubMed search nor a look at Dr. Weller's website indicated that he's published his study yet. I'll check periodically and report his results when they're avaialble. |
| Bill Bowser |
Posted - 02/21/2019 : 8:05:27 PM
The UK Daily Mail has this article about sunscreens, which doesn’t really provide much information.
https://www.dailymail.co.uk/health/article-6731267/U-S-FDA-proposes-new-regulations-counter-sunscreens.html
Bill Bowser - Cincinnati
Not lewd, not crude, just nude.
Nudists are everywhere, but they're hard to identify with their clothes on. |
| Bill Bowser |
Posted - 01/14/2019 : 10:54:40 PM
You just beat me to this. I logged on to post the same link.
I, and probably many others here, would be interested in hearing your comments Naturistdoc.
Bill Bowser - Cincinnati
Not lewd, not crude, just nude.
Nudists are everywhere, but they're hard to identify with their clothes on. |
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