Protecting yourself from all of the sun’s damaging effects is important, but it isn’t just sunburn from UVB rays, or long-term damage from UVA, that you have to worry about. In almost every product there is at least one ingredient that is unstable, ineffective, or downright dangerous.  There used to be some concern that the use of certain UV filers led to an increase in melanoma. This is still a somewhat controversial issue, but it appears to have been debunked(3).

However, there is plenty of evidence that numerous chemical UV filters have the potential to increase cancer-causing free radicals (6).  Others may have possible estrogenic and other adverse effects, and another is actually systemically absorbed and excreted in urine at a much higher rate than any other sunscreen filter (4,5)

The topic of sun protection could (and actually has been) covered in an entire book. We will do our best to cover everything here.

First let’s cover the wrong way to do it. Although there is some controversy surrounding the issue, studies have shown that some chemical products actually promote free radical production, thus causing more damage than they prevent! In brief “photo-unstable sunscreens may damage your skin.”

The Wrong Way to Protect Against UV

The topic of how not to protect against UV damage could actually be quite a lengthy one. For the purpose of this article we will just discuss some of the more damaging effects of sunscreens. In particular the chemical sunscreens that we buy in the stores can have adverse effects to the skin.

Simply applying a sunscreen with ingredients like avobenzone, bemotrizinol, or benzophenone-3 (Oxybenzone) isn’t enough. In fact, when used by themselves, some studies show that they do as much harm as good. There are a number of problems with using a commercials sunscreen alone. These include:

• Not all ingredients are created equal: It is important to be aware that not all ingredients are created equal. Some UV blockers work better than others, some are more stable and last longer, and each protects against only a certain range of UV wavelengths.
• Some ingredients cause harm: There are ingredients that are easily absorbed by the skin, and can cause damage. Oxybenzone for example, which is a very common ingredient in commercial sunscreens, has been shown to promote the production of free radicals.
• Some stabilizers cause damage: With ingredients that degrade, stabilizers are often used to make them last longer. This can lead to other problems. For example, in a sunscreen that uses avobenzone as a UV blocker, it may have octocrylene as a stabilizer. This increases the risk of irritation and adds to the low-level toxicity of the product.
• Constant chemical use on the skin has shown negative effects: Some studies have shown that the repeated use of chemical UV blockers can have negative effects; especially in those that promote free radical production.
• Micronized Ingredients are being found to cause problems. With physical UV blocks (the ones that look white on your skin) some companies have created micronized version of these products to make them more cosmetically elegant. Studies are showing that the micronized particles of zinc or titanium can actually be absorbed by the skin, and cause further problems.

With that in mind, it begins to become apparent that simply lathering up with chemical sunscreens each time you go out in the sun isn’t enough. To protect yourself, the right way, requires some special considerations.

The Right Way: Protection Against UVA, UVB, and Antioxidant Protection

To ensure that you have the best protection actually requires choosing the right product for the job. How much time will you be spending in the sun? Is it a cloudy day, or will you be out in the dead-heat of the midday sun? When you begin to look at the answers to these questions you can begin to choose the right product(s) to protect yourself. You also need to consider photo-stability of ingredients, the cosmetic elegance of the product, and whether to choose physical or chemical blockers. You also need to ensure that along with UV filters, you always have an antioxidant to reduce the production of free radicals.

Photo-stability of UV filters

The first thing to consider is the photo-stability of the ingredients. A sunscreen filter is photo-stable if it does not degrade in sunlight. Photo-unstable filters may lose their protective effect. The rate of degradation can be reduced by stabilizers. However, photo-stabilizers may increase the risk of irritation.

In practice, the most photo-unstable filter is avobenzone. Octyl methoxycinnamate is also photo-unstable but it does not degrade quite as quickly. However, the combination of avobenzone and octinoxate degrades faster than either alone (1).  Oxybenzone (benzophenone-3) is also photo-unstable.

List of Common UV filters and blockers

Chemical name: zinc oxide
UV spectrum: UVA-1 , UVA-2, UVB
type :physical
stability: stable
irritation : none
Pros: broad range protection, safe, anti-irritant
cons: white residue

Chemical name: titanium dioxide
UV spectrum: UVA-1, UVB
type: physical
stability: unstable
irritation: none
Pros: none
cons: insufficient protection against UVA-2, may generate free radicals, white residue

Chemical name: phenylbenzimidazole sulfonic acid  (ensulizole
UV spectrum: UVB
type: chemical
stability: stable
irritation: low
Pros: may stabilize other chemicals, water soluble in salt form
cons: No UVA protection

Chemical name: homosalate
UV spectrum: UVB
type: chemical
stability: unstable
irritation: low
Pros: none
cons: No UVA protection, Poor range of UVB protection

Chemical name: octyl methoxycinnamate (octinoxate)
UV spectrum: UVB
type: chemical
stability: unstable (partially stabilized by bemotrizinol/ Tinosorb M)
irritation: potential high risk
Pros: none
cons: risk of possible estrogenic and other adverse effects

Chemical name: octyl salicylate (octisalate)
UV spectrum: UVB
type: chemical
stability: unstable
irritation: low
Pros: none
cons: Poor range of  UVB  protection

Chemical name: octocrylene
UV spectrum: UVB, UVA-2
type: chemical
stability: very stable,sStabilizes other UV filters
irritation: low
Pros: very stable, stabilizes other UV filters
cons: weak, cannot be used alone

Chemical name: Benzophenone-3 (Oxybenzone)
UV spectrum: UVB, UVA-2
type: chemical
stability: unstable
irritation: high risk
Pros: none
cons: weak, cannot be used alone, promotes generation of free radicals, systemically absorbed and excreted in urine at a much higher rate than other sunscreen filters.

Chemical name: Avobenzone ( butyl methoxydibenzoylmethane, Parsol 1789, Eusolex 9020, Escalol 51)
UV spectrum: UVA-1, UVA-2
type: chemical
stability: unstable (Octocrylene, increases stability. Zinc oxide and titanium dioxide reduce stability)
irritation: low
Pros: Full UVA protection
cons: loses effectiveness over time,             may produce low-level toxicity with long-term use

Chemical name: 4-Methylbenzylidene camphor , 4-MBC, 3-(4-Methylbenzylidene) bornan-2-one , 3-(4-Methylbenzylidene)-dl-camphor
UV spectrum: UVB
type: chemical
stability: unstable
irritation: potential high risk
Pros: Stabilizes Avobenzone
cons:risk of possible estrogenic and other adverse effects, not approved in the USA

Chemical name: Ecamsule/terephthalylidene dicamphor sulfonic acid  (Mexoryl SX and XL)
UV spectrum: UVA-1, UVA-2
type: chemical
stability: stable
irritation: low
Pros: Ecamsule is acidic, the alkaline base used for neutralizing may cause irritation for some people.
cons: Full UVA protection, photo-stable, expensive -patented by L’Oreal

Chemical name: Bisoctrizole/methylene bis-benzotriazolyl tetramethylbutylphenol  (Tinosorb M, S)
UV spectrum: UVA-1, UVA-2, UVB
type: Chemical and Physical
stability: stable
irritation: low
Pros: Full UVA protection, photo-stable,pPartially stabilizes octinoxate
cons: Not approved in the USA

Stabilized Avobenzone

Due to the stability issues of avobenzone companies developed stabilized formulations.

Neutrogena Sunblock, Ultra Sheer Dry-Touch SPF uses Helioplex (a formulation containing avobenzone and oxybenzone). Banana Boat offers ‘AvoTriplex’, a formulation containg: avobenzone 3% , homosalate 8.78% , octinoxate 5% , octisalate 5% , octocrylene 2.5% , and oxybenzone 5%.

The problem with these products is the use of oxybenzone, which is a high-risk product.

European UVA filters

Until recently the only UVA filter available in the USA was Avobenzone. Sun-savvy consumers would therefore buy and import their sun protection products from abroad.  The most popular of these products was L’Oreal La Roche-Posay, which is formulated with Mexoryl SX and XL

In 2006 the FDA approved the sales of sun protection product containing Mexoryl SX and XL. It is now possible to buy L’Oreal La Roche-Posay products, as well as cheaper products made by their umbrella companies (Vichy Capital Soleil, L’Oreal Solar Expertise and Garnier Ambre Solaire).

Tinosorb (S and M) is an amazing hybrid filter and we will discuss it more, later in this article. At the time of this writing it is still not approved by the FDA. Those who are seriously committed to maintaining excellent skin health are still forced to import this product from the European Union or Canada.

Cosmetic elegance

Next we need to consider the cosmetic elegance of the sun screen. This is a concern to many.

Due to the nature of the UV filters, it is actually not easy to manufacture and effective UVA/UVB sun protection products which are also cosmetically elegant.  High oil content and excessive alcohol use are a problem for those with sensitive skin.  Excessive shininess (as opposed to the preferred matt look) and balling (when the product ends up forming little ‘balls’) are also a problem for those who have to look presentable during the day.

Physical and Chemical UV Protection

When prolonged exposure to the sun is planned, the best UV protection is offered by new the UV filters Mexoryl SX and XL. These new filters offer outstanding protection against the entire UVA range, they are photo-stable, non-irritating and have no reported toxicity concerns.

Physical protection (UV blocking) used to be only available with Zinc Oxide and Titanium dioxide.  Although Zinc Oxide has a good safety profile, there are numerous concerns about Titanium dioxide. However, non-micronized zinc keeps out both UVA, and UVB rays and is a good alternative for those with extremely sensitive skin.

With the absence of easily absorbed chemicals there isn’t a lot of damage that can be done by the sunscreen itself. The problem with these particular products is that they leave the skin white, which may not always be the look you want for that day on the beach.

It is worth noting that some products contain Zinc Oxide with the chemical Avobenzone, this combination should really be avoided as the already unstable Avobenzone can be degraded even more by Zinc Oxide.

An excellent alternative to the purely physical blockers is the new hybrid (chemical and physical blocker) Tinosorb (S and M). This insoluble powder is usually added to the water phase of a product, and it acts as both a chemical UVA filter AND a UVA reflector. In addition it partially stabilizes the commonly used UVB filter Octinoxate.

When a more cosmetically elegant sunscreen is required, a chemical sunscreen can be used with the antioxidant. What is important to ensure is that you choose one with ingredients that don’t generally have harmful effects, and that protect from both UVA and UVB rays. It is also quite important to understand that with some ingredients there isn’t a lot of studies that look at the long term effects or repeated use. For this reason chemical sunscreens should not be over used.

Anti-Oxidant Protection to Prevent Free Radical Production

Whenever you go plan to expose yourself to the sun (and even when you aren’t using a sunscreen) you should be using an antioxidant. The process is known as layering, and the antioxidant always goes on first. This works to counter the free radical production that comes both from sun exposure, and from the use of chemical UV blockers.

What do I use?

Sun protection for my face, daily use during the summer:

Last year I was using Anthelios XL Fluide Extreme from La Roche-Posay line. However, with the release of the tinosorbs I was ready for a change, so this year I am trying RoC Minesol protect SPF 60 spray-on .  I am not too happy with the formulation, although it is an elegant product, and the next sunscreen I will try is one of the Bioderma ones, also with the Tinysorbs.

I will write another post soon, with a detailed analysis of these sunscreens, and others!

All over body protection for when I am at the beach.

I used to use Ultra Sunscreen SPF 30+ made by the Australian Cancer Council. I especially loved their spray on, which was quick and effective on the beach. However, since learning more about sun protection I realized that this is really quite a bad formulation. In fact, I have given up on body sunscreens all together.

Most of my sun exposure occurs when I am windsurfing, sailing, kayaking or snorkeling.  I have had some nasty burns, and I have too many moles on my body. So, now I use a nice pair of UV protection swim shirts (SPF 50), and swim tights.  It may look silly, but I love being active on the beach and on the water, and there is no point taking risks.

Botanical Protection From UV

For the days when only a short time will be spent in the sun (quick trip to work, working in a windowless office), botanical protection may be a good choice. An effective antioxidant serum can be made using ingredients that have been proven to prevent UVB damage, reduce free radical activity and even reverse sun damage.  Using natural ingredients ensures that you’re not exposing your body to chemicals, and that you still have basic protection from the sun.

No matter what, a good antioxidant serum is essential to maintaining skin health, and should always be layered under your chemical or physical sun protection product. This will actually be the topic of the next article in this series of 3 on sun protection.

References

1.  Maier H, Schauberger G, Brunnhofer K, HoÈnigsmann H. Change of Ultraviolet Absorbance of Sunscreens by Exposureto Solar-Simulated Radiation. Division of Special and Environmental Dermatology, University of Vienna Medical School, Vienna, Austria; Institute of Medical Physics and Biostatistics, University of Veterinary Medicine Vienna, Vienna, Austria; Austrian Consumers’ Association, Vienna, Austria

2. Dr. G. Todorov. Sun Blocks/Sun Screens – an  online resource. Various pages used in researching chemical skin care ingredients. Accessed July 20, 2008 from http://www.smartskincare.com/skinprotection/sunblocks/

3.  Sunscreen use and the risk for melanoma: a quantitative review. Dennis LK, Beane Freeman LE, VanBeek MJ. College of Public Health and College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA. leslie-dennis@uiowa.edu

4. mSarveiya V, Risk S, Benson HA. Liquid chromatographic assay for common sunscreen agents: application to in vivo assessment of skin penetration and systemic absorption in human volunteers. Faculty of Pharmacy, University of Manitoba, Winnipeg, Man., Canada.

5.   Janjua NR, Mogensen B, Andersson AM, Petersen JH, Henriksen M, Skakkebaek NE, Wulf HC. 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.

6.  Schallreuter KU, Wood JM, Farwell DW, Moore J, Edwards HG. Oxybenzone oxidation following solar irradiation of skin: photoprotection versus antioxidant inactivation. Department of Dermatology, University of Hamburg, Germany.

7.    Negishi, K; Higashi, S; Nakamura, T; Otsuka, C; Watanbe , M; Negishi, T. (2007) Oxidative DNA Damage Induced by 364-nm UVA Laser in Yeast Cells. Originally published by the Japanese Environmental Mutagen Society. Accessed online July 16th 2008 from http://www.jstage.jst.go.jp/article/jemsge/28/2/74/_pdf

8.   Brannon, Heather MD. (March 23, 2008). Effects of Sun on the Skin: Cellular Skin Changes Caused by UV Radiation. Article hosted on about.com. Accessed July 16th, 2008 from http://dermatology.about.com/cs/beauty/a/suneffect.htm

9.   Hugget, J. (June 28, 2005) Less Than Full Protection: Most Sunscreens Do Only Half the Job, Blocking Unsafe UVB Rays But Not Skin-Damaging UVA. Can We Get Better Cover. Washington Post. Accessed July 16th 2008 from http://www.washingtonpost.com/wp-dyn/content/article/2005/06/27/AR2005062701099.html

10. Eldich, R Dr. and Various other Authors (2004) Photoprotection by Sunscreens with Topical Antioxidants and Systemic Antioxidants to Reduce Sun Exposure.  Journal of Long-Term Effects of Medical Implants. Begal House Inc. Accessed July 16th 2008 from http://www.pacificcenterplasticsurgery.com/articles/Photoprotection-by-Sunscreens.pdf

11.  Reinheckel, Thomas,  Bohne, Marisela,  Halangk, Walter,  Augustin, Wolfgang,  Gollnick, Harald. Evaluation of UVA-mediated oxidative damage to proteins and lipids in extracorporeal photoimmunotherapy. A Study hosted on findarticles.com Accessed July 16th 2008 from http://findarticles.com/p/articles/mi_qa3931/is_199905/ai_n8838478

12. Columbia-Presbyterian Medical Center, no author listed. Two Cancer Studies: Tomatoes, Green Tea, and Cancer. Originally published in the P&S Journal: Fall 1997, Vol.17, No.3 Research Reports. Accessed July 16th 2008 from http://cpmcnet.columbia.edu/news/journal/journal-o/archives/jour_v17n03_0009.html

13. MakeupAlley, no author listed. List of UVA-Protective Sunscreens. Accessed July 20th 2008 from http://www.makeupalley.com/user/notepad/sunscreens

14. MakeupAlley, no author listed. Information and frequently asked questions about sunscreen. Accessed July 20th 2008 from http://makeupalley.com/account/vn.asp?u=sunscreenFAQ