Study: Many Sunscreens May Be Accelerating Cancer
WASHINGTON (May 24, 2010) -- Almost half of the 500 most popular sunscreen products may actually increase the speed at which malignant cells develop and spread skin cancer because they contain vitamin A or its derivatives, according to an evaluation of those products released today.
AOL News also has learned through documents and interviews that the Food and Drug Administration has known of the potential danger for as long as a decade without alerting the public, which the FDA denies.
Note that this story is from a year ago and the FDA did the study over 10 years ago and are just last year telling us about Vit A in sunscreens.
For those of us that are/were sun worshippers, have you ever heard of the connection between topical Vit A in sunscreen and the incidence of skin cancer?
For Vit D3 health reasons we know that exposure half naked for 20 min...10 min on a side is an excellent source of Vit D3...without sunscreen.
Avoid sunscreen and avoid skin burning and you avoid skin cancer.
Hey, I get to give another "chemist's view" on this! Quick disclamer: I'm only talking about mechanisms here and trying to extrapolate to the effects on humans. Just like in my last "chemist's view" on AGEs, I'm making no representation about our evolutionary adaptations to handle things. I'm just talking about the underlying chemistry.
I'll start at the beginning: Light that we see comes in many different "colors", we call them "red", "blue", "green", etc. Ultraviolet light also comes in may different "colors", the terms physicists use are "UVA", "UVB", "XUV", "VUV" (the atmosphere absorbs all of the XUV and VUV, so we don't encounter that in the real world). Not all sunscreen absorbs all colors of UV. They generally absorb the colors of UV that cause tanning and burning (because that's the observable that people care about), but they don't generally block the higher energy UV colors that actually cause the cancer. Because the effect of that isn't marketable, no one would know it's happening.
Without sunscreen, your skin "sees" some UV colors and starts to "tan". The tanning is your body's natural protection against the higher energy UV colors that cause the cancer. So as long as you're not out long enough to get burnt (actual skin damage), the tan protects you against the bad stuff.
So strike 1 against sunscreen: it stops the good stuff that promotes tanning and lets through the bad stuff that causes cancer (that our tan would protected us against if it was allowed to form).
Strike 2 against sunscreen: The UV that causes us to tan is the same color of UV that is used in the formation of Vit D which also protects against cancer.
Now, lets say that there was a magical sunscreen that blocked 100% of all colors of UV, would I feel comfortable using it? No. Here's why:
Sunscreen works by "absorbing" UV rays. How does it work. Well it's generally a long polycyclic aromatic with lots of conjugated double bonds. The UV light is resonate with the electronic transitions of the conjugated states. When the UV light hits the sunscreen molecule, it promotes an electron into a higher state which actually breaks one of the double bonds. Most of the time the sunscreen molecule will then shed that extra energy it just absorbed as heat and reconnect that double bond. But sometimes it won't and you'll be left with a free radical (just like you're probably aware - since you're reading paleohacks - PUFAs are susceptible to oxidative damage - just image a sunscreen molecule as a more reactive PUFA). So when you started, you put a reasonably harmless chemical on your skin (or else the FDA wouldn't allow it to be sold), but it's interaction with light turns it into a potential carcinogen just like PUFAs and PAHs.
Strike 3 against sunscreen: The act of doing it's job (absorbing UV) turns it into a potential carcinogen which is now slathered over your largest organ.
Personally, ever since I worked through these mechanisms, I've never used sunscreen again.
That enough chemist rant for now. I'm happy to add to it, just don't want to bore you to death just yet.
I agree that most sunscreens are detrimental to health. I do believe that there are a nice assortment of sun blocks that are protective without doing harm. EWG agrees with me on this. I use an organic (zinc only) sunblock every single day. I do try to expose my limbs to sun for 15-20 minutes a day for D but no more than that. My face, neck, ears and chest are always covered with block. Unfortunately I've seen a number of people eaten up with cancer of the head and neck and it is beyond frightening. A good friend of mine just yesterday had a huge crater the size of a tennis ball cut out of her leg because at 40 she was diagnosed with skin cancer. It would take a whole lot more scientific evidence that a well-formulated sun block does more harm than good to get me to change my sun block habit.
So what do you do if you are at the beach all day, or out in the sun all day? I don't know about you guys, but I'm def not gonna wear long sleeves, and pants when I spend the day in the sun. So how do we protect ourselves from hours of continuous sun exposure?
I started using Extra Virgin Coconut Oil (yes, the kind you cook with) before I go out in the sun. No more sunburn, just a nice golden tan! It also is a great moisturizer, makes your skin feel nice and silky. I live near the beach and am out in the sun ALOT during the summer months. I found on quite a few 'paleo' sites and blogs the use of Coconut Oil for tanning. Sounded crazy, but I thought I'd give it a try. Of course, I wouldn't try going out in the sun for 4 hours the first time, but I usually am out in the sun for 90 min. to 2 hours a day several times a week, and the coconut oil works great!
For discussion purposes, I brought this up to my dermatologist a few months back. She instantly shunned the concept, saying that the depletion of the o-zone layer etc, has lead to far stronger rays than we would have experienced, and I'd basically be asking for cancer if I didn't wear SPF 50+ anytime I was out in the sun for more than 30 min. Unfortunately, I was getting a pre-cancer frozen off my lip at the time so I didn't have much of a leg to stand on.
For better or worse, I still don't wear the stuff. The idea of it doesn't make sense to me at all.