Continuing with sunscreens, using PABA may by itself cause problems as it was shown to directly damage human DNA. 1 Then as the UV-B is blocked proportionally to the level of sun protection factor (SPF) of the sun screen. SPF levels are calculated only for UV-B protection not UV-A.

By “protecting” from UV-B exposure it reduces the production of protein proopiomelanocortin (POMC). Though compounds like oxybenzone, which has been around since 1978, blocks both UV-A and UV-B. It however has been linked to hormonal disruption and skin cancer. 2

Though one study showed it would take using massive amounts for decades to cause. 3 Additional studies showed it may be safe as they show no accumulation in plasma after several days of application., 4,5,6

The Wang study was in adults and did note that children were much more sensitive to similar compounds. 3 So, the current evidence shows it is potentially safe, and I don’t want to be a fear monger, but it doesn’t mean later studies won’t.

As I ended the last blog posting the is the problem is proving a compound does not cause illness. It is impossible to test it in every scenario. When it comes to sun screens it seems to go on and on.

Ok last one, the chemical found in many current sun screens is retinyl palmitate. It is a type of vitamin A which has been found in mice to cause skin cancer. Results in humans are less conclusive or perhaps not.

It seems the doctors who have, as they say, a dog in the fight believe it is totally safe, but others are not so sure. I didn’t intend to get too deep into sunscreens. But let me direct you, if you need to know more, to an excellent article by Sonya Lunder. There you’ll find I believe fair information on vitamin A compounds in sunscreens and cosmetics. 7

Unfortunately, because of many issues it is difficult to get at the truth. For example like above with retinyl palmitate, just because someone works for a company doesn’t mean their opinion is wrong. But often they are biased toward there employer so best to try to find an independent voice.

Whether sun screens reduce risk of cancer later is unknown but as skin damage is known to be a precursor to skin cancer it might. But are they worth the risk? The final point I would like to make concerning sunscreen chemicals is we and our environment have essentially been guinea pigs for them.

Considering how skin cancer will end up effecting 1 in 5 Americans by age 70. 8 It is a real issue. But how can and why should we have trust in those who are there to protect us and those that sold us these products?

As they did and continue to sell as well as promote using sunscreens with substances that we were led to believe protect us only to find out later they have put us at more risk. Perhaps harsh but this research is not new.

Yes, you can probably by using research prove everything is bad for you. That makes trying to get a clear picture so difficult and why as I have written before people just throw up their hands and give up. Unfortunately, I believe this is what those who benefit from our ignorance want.

That is why you must educate yourself and find several creditable sources to come to a consensus on what is true. Therefore, I try to make these posts short and to the point. To make the most of your valuable time. Could I be wrong? Of course, but the truth is also important to me, so I work hard to find it! A startling statistic in my next blog post of this series.

  1. Gulston M, Knowland J. (August 1999). Illumination of human keratinocytes in the presence of the sunscreen ingredient Padimate-O and through an SPF-15 sunscreen reduces direct photodamage to DNA but increases strand breaks. 444:49-60.
  2. Schlumpf M, Cotton B, Conscience M, et al. (2001). In vitro and in vivo estrogenicity of UV screens. Environ Health Perspect. 109(3):239-244.3. A Wang SQ, Burnett ME, Lim HW. (2011). Safety of Oxybenzone: Putting numbers into perspective. Arch Dermatol. 147(7):865-866.
  3. Wang SQ, Burnett ME, Lim HW. (2011). Safety of Oxybenzone: Putting numbers into perspective. Arch Dermatol. 147(7):865-866.
  4. Janjua NR, Mogensen B, Andersson AM, et al. (2004). Systemic absorption of the sunscreens benzophenone-3, octyl-methoxycinnamate, and 3-(4-methyl-benzylidene) camphor after whole body topical application and reproductive hormone levels in humans. J Invest Dermatol. 123(1):57-61.
  5. Gonzalez H, Frbrot A, Lark oO, et al. (2006). Percutaneous absorption of the sunscreen benzophenenone-3 after repeated whole-body applications, with and without ultraviolet irradiation. Br J Dermatol. 154(2):337-340.
  6. Janjua NR, Kongshoj B, Andersson AM, et al. (2008). Sunscreens in human plasma and urine after repeated whole-body topical application. J Eur Acad Dermatol. 22(4):456-461.
  7. Lunder S. (June 27, 2011) What scientist say about vitamin A in sunscreen. https://www.ewg.org/research/what-scientists-say-about-vitamin-sunscreen
  8. Stern RS. (2010). Prevalence of a history of skin cancer in 2007: results of an incidence-based model. Arch Dermatol. 146(3):279-282.

*The information posted above is for educational purposes only. Always check with your doctor before initiating any changes in your medical treatment. If you do not, then The Two-Minute Health Fact, Dr. Judson Somerville, nor The Optimal Dose is responsible!


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