Sunshine and You - A word on sunscreens

As the heat continues this summer, we all need to remember to use Sun Screen while we are outside enjoying the sun.  Whether you are hiking, kayaking, sitting under your favorite shade tree, or spending the day in and around the water, there are a three things you will want to remember when using Sun Screen.

First, get rid of your old sun screen.  It only has a shelf life of 3 years, and that is only if the product is not exposed to high temperatures.

Second, read the labels.  Using a mineral based sun screen, also known as a broad spectrum sunscreen, containing Zinc Oxide and or Titanium Dioxide provides a more balanced protection from both UVA, and UVB rays. Also look at the SPF.  Higher SPF values, up to 50, provide greater sunburn protection. Studies have shown that sunscreens with SPF above 50 do not give you any additional protection. And then look at the water resistant time frame.  That will tell you how often to re-apply with water exposure or sweating.

Third, Reapply.  According to Harvard Health Publications, sun screen should be re-applied every 2 hours. If you are in the water or sweating reapply as directed on the bottle.

When you’re shopping for your sun screen, there are a few types on sun screens to avoid.  One of those being combined with insect repellant.  Sun screen needs to be re-applied a minimum of every 2 hours, whereas insect repellant does not need to be used that often.   It’s also recommended to avoid using sprays. It’s harder to know if you are covering all of your exposed skin, and it’s easier to inhale the contents while spraying.

More On Sunscreens

The sun helps us produce Vitamin D, an important part of how we utilize calcium. Vitamin D also plays an important role as an anti-inflammatory. On the other side, too much sun can be damaging to our skin. This damage can accumulate over the years and can lead to serious skin problems including various skin cancers. Simply put, there is no such thing as a “healthy tan.” Researchers believe that increased UV exposure may have caused the marked increase in melanoma incidence noted among women born after 1965. Tanning parlors expose the skin to as much as 15 times more UV radiation than the sun and likely contribute to the melanoma increase1.

Avoidance and protection are the keys to reducing the risk to these potential problems. Reducing the intensity of the sun by choosing mornings and evenings, keeping to the shade, wearing sun blocking clothes and hats, and wearing sun glasses can be greatly helpful. And, of course, protecting your skin with sunscreen can mitigate the damage when you are playing in the sun. However, not all sunscreens are created equal. According to the Environmental Work Group (EWG) 1, an independent group of scientists who evaluate sunscreens based on current scientific literature, there are aspects about sunscreens that are less favorable.

  • Vitamin A (retinyl palmitate, retinol or vitamin A). Government data show that tumors and lesions develop sooner on skin coated with creams laced with vitamin A2. However, more recent research has shown that retinol slows certain tumors such as melanomas. (See especially Shapiro 2013) The research currently seems to favor of retinol in sunscreens.
  • Oxybenzone and Octinoxate: A synthetic estrogen that penetrates the skin and can disrupt the hormone system. Instead, look for zinc oxide, 3% avobenzone or Mexoryl SX. They protect skin from harmful UVA radiation.
  • No insect repellent. If you need bug repellent, buy it separately and apply it first.
  • Reapply cream often. Sunscreen chemicals sometimes degrade in the sun, wash off or rub off on towels and clothing.
  • Don’t fall for high SPF labels. Anything higher than SPF 50+ can tempt you to stay in the sun too long. Stick to SPFs between 15 and 50. Reapply often.

Check out your sunscreen: For extensive information on sunscreens go to EWG’s website. EWG provides a list of the sunscreens they reviewed and rated. See how yours measures up to the research and how it compares to the other ones on the market2.



Extended References

Retinol & Vitamin A

  1. Alizadeh F1Bolhassani A2Khavari A1Bathaie SZ3Naji T4Bidgoli SA4. Retinoids and their biological effects against cancer. Int Immunopharmacol. 2014 Jan;18(1):43-9. doi: 10.1016/j.intimp.2013.10.027. Epub 2013 Nov 14.
  2. Hassel JC1Amann PMSchadendorf DEichmüller SBNagler MBazhin AV. Lecithin retinol acyltransferase as a potential prognostic marker for malignant melanoma. Exp Dermatol. 2013 Nov;22(11):757-9. doi: 10.1111/exd.12236.
  3. Shapiro SS1Seiberg MCole CA. Vitamin A and its derivatives in experimental photocarcinogenesis: preventive effects and relevance to humans. J Drugs Dermatol. 2013 Apr;12(4):458-63.
  4. Sorg O1Saurat JH. Topical retinoids in skin ageing: a focused update with reference to sun-induced epidermal vitamin A deficiency. Dermatology. 2014;228(4):314-25. doi: 10.1159/000360527. Epub 2014 May 9.
  5. Stevison F1Jing J1Tripathy S1Isoherranen N2. Role of Retinoic Acid-Metabolizing Cytochrome P450s, CYP26, in Inflammation and Cancer. Adv Pharmacol. 2015;74:373-412. doi: 10.1016/bs.apha.2015.04.006. Epub 2015 May 27.
  6. Zhang ML1Tao YZhou WQMa PCCao YPHe CDWei JLi LJ. All-trans retinoic acid induces cell-cycle arrest in human cutaneous squamous carcinoma cells by inhibiting the mitogen-activated protein kinase-activated protein 1 pathway. Clin Exp Dermatol. 2014 Apr;39(3):354-60. doi: 10.1111/ced.12227.
  7. Zito G1Saotome I1Liu Z2Ferro EG1Sun TY1Nguyen DX2Bilguvar K1Ko CJ3Greco V4. Spontaneous tumour regression in keratoacanthomas is driven by Wnt/retinoic acid signalling cross-talk. Nat Commun. 2014 Mar 26;5:3543. doi: 10.1038/ncomms4543.

Titanium Dioxide

  1. Browning CL1The T2Mason MD3Wise JP Sr1. Titanium Dioxide Nanoparticles are not Cytotoxic or Clastogenic in Human Skin Cells. J Environ Anal Toxicol. 2014 Nov;4(6). pii: 239. Epub 2014 Sep 6.
  2. Mao Z1Xu BJi XZhou KZhang XChen MHan XTang QWang XXia Y. Titanium dioxide nanoparticles alter cellular morphology via disturbing the microtubule dynamics. Nanoscale. 2015 May 14;7(18):8466-75. doi: 10.1039/c5nr01448d.
  3. Zhang X1Li W1Yang Z2. Toxicology of nanosized titanium dioxide: an update. Arch Toxicol. 2015 Dec;89(12):2207-17. doi: 10.1007/s00204-015-1594-6. Epub 2015 Sep 21.

Oxybenzone & Sunscreens

  1. Amar SK1Goyal S1Dubey D2Srivastav AK2Chopra D2Singh J2Shankar J3Chaturvedi RK4Ray RS5. Benzophenone 1 induced photogenotoxicity and apoptosis via release of cytochrome c and Smac/DIABLO at environmental UV radiation. Toxicol Lett. 2015 Dec 15;239(3):182-93. doi: 10.1016/j.toxlet.2015.09.024. Epub 2015 Oct 9.
  2. Amar SK1Goyal S1Mujtaba SF2Dwivedi A2Kushwaha HN2Verma A2Chopra D2Chaturvedi RK3Ray RS4. Role of type I & type II reactions in DNA damage and activation of caspase 3 via mitochondrial pathway induced by photosensitized benzophenone. Toxicol Lett. 2015 Jun 1;235(2):84-95. doi: 10.1016/j.toxlet.2015.03.008. Epub 2015 Mar 20.
  3. Coronado M1De Haro HDeng XRempel MALavado RSchlenk D. Estrogenic activity and reproductive effects of the UV-filter oxybenzone (2-hydroxy-4-methoxyphenyl-methanone) in fish. Aquat Toxicol. 2008 Nov 21;90(3):182-7. doi: 10.1016/j.aquatox.2008.08.018. Epub 2008 Sep 10.
  4. Nakagawa Y1Suzuki T. Metabolism of 2-hydroxy-4-methoxybenzophenone in isolated rat hepatocytes and xenoestrogenic effects of its metabolites on MCF-7 human breast cancer cells. Chem Biol Interact. 2002 Feb 20;139(2):115-28.
  5. Schlumpf M1Cotton BConscience MHaller VSteinmann BLichtensteiger W. In vitro and in vivo estrogenicity of UV screens. Environ Health Perspect. 2001 Mar;109(3):239-44.