It’s sunscreen week!
This is another guest post from my amazing (and funny, and smart, and talented) skin care correspondent, Svea. In fact, her crazy knowledge of sunscreen and how it relates to acne has resulted in a post that was so epic, it needed to be broken down into three parts!
This is part 1.
Also, check out Svea’s own blog here. Go. Do it.
Here Comes the Sun!
Talking about sunscreen is an extremely delicate topic.
It took me loads of time to write this article, because I felt that it had to be INFORMATIVE, HELPFUL and UNDERSTANDABLE at the same time – with all scientific backgrounds listed and explained. All in all: as COMPLETE as possible!
It’s always easy to say that all sunscreen is crap and that long sleeves, crazy hats, enormous sunglasses and living in a crawl space cellar during the summer months is the best way to get “rid” of the sun. On the other hand, who doesn’t love to spend a few hours at the beach, to lay down in a park doing nothing at all, to go swimming, or on a biking tour?
Sombreros are not always practical and a 100% harmless sunscreen simply does not exist (sad as it is), so it’s all about finding the best possible compromise. And that’s extremely tricky!
Somehow I was intrigued by this type of entrapment and maybe that’s why I couldn’t stop myself from researching for a very long time. This topic was simply so sarcastically thrilling!
Well, I guess the articles still aren’t totally complete and will probably be quite hard to read because it‘s long and very specific and doesn’t offer a simple all-purpose solution that works for everyone, everywhere, every time.
Nevertheless, I hope that it‘ll give you a few helpful hints!
The Sunburn of the Pharaoh
I warn you: Never attempt to try this! It‘s only an old anecdote. And a nice start for our long and exhausting sunscreen tour!
The divine Pharaoh was tired of it all: Intolerable itchiness, crusts, nodules and pustules everywhere! He tried the only method of healing, his medical scholars could recommend to him and spent hours and hours sunbathing in the merciless Egyptian midday sun!
The inevitable sunburn was severe and caused his skin to peel off in large, red shreds. But after the healing process was completed, his nightly itching terror stopped – at least for a while. Neither he nor his doctors knew why the treatment helped, and what had left him scratching all night.
Small scabies mites were living in his outermost skin layers, drilling passages while depositing eggs and excrements. The itching was the result of an allergic reaction of his body to the presence of the mites. The dead pieces of skin, flaking away after every sunbathing session, contained a large part of the mites and the divine Pharaoh came to a rest.
For a while.
In the meantime, the remaining mites kept reproducing and the game began all over again! The divine Pharaoh was tired of it all and went out into the merciless midday sun…
That‘s a story a dermatologist told me once, but I can‘t tell if it‘s really a true story.
Anyway, believe it or not, just as you please! And let‘s come straight to the subject!
Hormones in Sunscreens
Leaving behind the Pharaoh and his mites, spending hours and hours in the sun is definitely out!
I‘m sure, you’ve already heard the “news“ about chemical UV filters in most conventional sunscreen products acting like hormones. Whoever wants to protect him or herself against sunburn has to use large amounts of sunscreen – and in the end of your holiday, you’ve spread several deciliters of it onto your skin!
A good shower or a bath in the sea won‘t wash away all cream residues. Tiny amounts of your sunscreen may penetrate through your mouth or your skin into your organism.
During a study at the University of Zurich in 2000 / 2001, ultraviolet (UV) filters have been detected in the breast milk of women, who were using conventional sunscreens on a regular basis. The alarming result: In the laboratory, common UV filters protecting against the most harmful UV-B rays stimulated the growth of human breast cancer cells. Whoever speaks German, can read more about it here. For everyone else: click here.
In addition, recent studies have raised concerns over a gradual build-up of parabens in the body. Parabens are added as preservative agents to many commercial sunscreens (and a lot of other beauty products) and have been linked to hormone disruption – and again cancer.
In addition, these chemicals have been shown to increase UV light absorption. This means, parabens can increase sun damage to the skin! That‘s why it’s important to avoid them especially in sunscreen products and day moisturizers.
However, it‘s logical that we should stay away from as many synthetic irritants as possible!
Further readings about parabens: click here and here.
Its basically impossible to find a sunscreen that does not generate free radicals itself. Potentially harmful chemicals such as dioxybenzone and oxybenzone have been proven to be some very powerful free radical generators.
This means that the active ingredients in most sunscreens on the market generate free radicals, in order to avoid the formation of free radicals during sun exposure. Ha! Funny, isn‘t it?
In the end, after lots of investigative reading (always keep in mind that I‘m neither a dermatologist nor an analytical chemist or a sunscreen expert), I found out that a nanotechnology-free zinc-oxide-based sunscreen still appears to be the safest bet when it comes to using sunscreens.
While even larger particles of zinc oxide inevitably produce free radicals, at least their relatively large size significantly reduces the probability of these particles being absorbed and subsequently producing free radicals near any living tissue.
What about titanium dioxide?
There are two types of it, rutile and anatase. These polymorphs of titanium dioxide differ in certain properties. As it comes out, rutile is less photo-reactive compared to anatase: It has a very high refractive index and high dispersion properties. This means, that rutile titanium dioxide tends to reflect UV rays rather than absorbing them.
Sure, you still might want to be concerned about which type of it is present in your sunscreen. Generally, rutile is used, but if you like, you can still try to contact the manufacturing companies. However, keep in mind that you still have to BELIEVE in whatever they tell you!
Zinc oxide offers a good uniform UVA and UVB coverage between 290-400 nm and is the only non-synthetic sunscreen agent providing a broad spectrum protection against UVA and UVB rays.
In comparison, titanium dioxide protects well against UVB rays, blocks short UVA rays, but misses a large portion of the longer ones.
Generally, externally applied zinc oxide doesn’t cause any allergic reactions. There are only a handful of extremely rare cases of zinc oxide not being tolerated. The mineral sits on top of your skin and disperses the sunlight without allowing it to get to the skin‘s surface, and – as long no nano-technology is involved – it won‘t be absorbed into your skin.
In addition, the protection factor does not diminish in the course of the day. This means, that you don‘t have to put on your sunscreen several times a day! And while synthetic filters lose their effectiveness after approximately one year, mineral sunscreens can be used for a much longer period (depending on the product up to three years). So you‘ll probably still be able to use the mineral sunscreen you bought last year – at least as long as the ingredients in it didn’t turn rancid!
Also, zinc oxide is a mild antimicrobial and wound healing substance and is considered to be non-comedogenic. This makes it a pretty good ingredient for acne prone and sensitive skin (think of zinc oxide ointments for babies)! This is also a reason why zinc-oxide based mineral makeup works so well for many people with a problem skin – and it provides a little sun protection at the same time!
Micronized and Nano
There are many reports which claim that nano particles of titanium dioxide or zinc oxide have the ability to pass the skin‘s outer layers. That‘s why those so-called nanosunscreens have a less whitening effect on your skin compared to other products using bigger mineral particles.
In addition, there are concerns that these nano-sized minerals are much more photo-reactive than coarser particles and may generate free radicals which can cause cell damage. Especially spray-on sunscreens and powders containing nanoparticles increase the risk of inhalation as the particles travel in the air.
Some manufacturers have addressed this issue by coating the particles with silicon, aluminum oxide or stabilized lecithin, forming aggregates sized 200 – 500 nm, in order to prevent free radical formation.
However, some people tend to break out if their sunscreen contains silicon coated particles. Unfortunately, the manufacturers only list the ingredients themselves, but never the coating substances. You have to be VERY insistent if you want to know a little more about it (and you‘ll never know if you‘ll get an honest reply).
Micronized minerals, which are at least 250 nanometers in diameter, are preferable over nano-particles which are around 100 nm or less. The difference between micronized and nano-sized is like the difference between a million = micro and a billion = nano. The larger micronized minerals are generally believed to be safer with a lower risk of inhalation and skin penetration.
You can find an extremely mind-opening article about the risks of nano-sunscreens here.
A scientific essay with background information about the potential phototoxic effects of nano-sunscreens: click here.
And if you want to know more about the production process of sunscreen minerals, zinc oxide, titanium dioxide and other minerals, you can find lots of information here.
The Goth Chick Look
The spreadability of most mineral sunscreens is completely different compared to chemical based products.
The mineral micro pigments in physical sunscreens reflect UV rays just like a mirror. However, these minerals, especially zinc oxide, are not water-soluble. On the other hand, chemical sunscreen agents can even be incorporated in plain water and convert the absorbed energy from UV radiation into heat – directly on your skin!
I guess many of you don‘t like the fact that most mineral sunscreens have a pasty consistency, are a “little“ more difficult to apply, have a whitening effect on your skin and often feel sticky or greasy. I think that there aren‘t many of you who want to look like a mixture of a geisha and a bacon rind by choice.
Fortunately, there seem to be a few less oily and less whitening products out there. Finally. Have a look at my sunscreen tips towards the end of the article! However, if you still find that your sunscreen is too pasty, you can try to warm it a little bit in the palms of your hands and distribute it in many little portions all over your skin. You‘ll see that you‘ll be able to “work“ it in much more easily – preferably without rubbing or pulling your skin!
Whoever of you is still afraid of the whitening effect can blend some mineral foundation powder into the sunscreen before applying it to the face. A little darker tint than the one you are using normally should work perfectly. Mix only the smallest amounts (it‘s not easy to mix!) and store in the fridge!
Or do you think you are too lazy to do that?
Luckily, there are a few manufacturers (for example Marie Veronique Organics), who sell ready-made tinted mineral sunscreens in a few different shades.
Oils in Sunscreens
Due to the light-exposed application of sunscreens and daytime moisturizers during the summer months, these products require the utilization of oxidation-stable oils without or (in regular skin care products) with only a low content of polyunsaturated fatty acids.
The well known Mallorca acne (acne aestivalis), for example, is caused by toxic metabolites: solar radiation and heat oxidize and decompose unstable lipids in cosmetic products.
On the other hand, UV-light-induced skin aging is much more influenced by the oxidation of the skin’s own lipids. Yet, eating a balanced and healthy whole-foods diet can have a positive influence on the composition of your sebum.
You see, it makes sense to confront this problem holistically! It‘s in your hands!
But let‘s get back to the topic: oils in sunscreens!
Some oils are excellent stabilizers for others: jojoba oil, coconut or babassu oil, meadowfoam oil or marula oil, for instance. Argan oil, rice germ oil, baobab oil, avellana oil and sesame oil are relatively resistant to UV-radiation as well, but still contain a certain amount of linoleic acid – which can dissolve existing comedones and can therefore be helpful for acne prone skin types.
Also, plant butters with a low proportion of polyunsaturated fatty acids such as shea, mango and cupuacu butter, can be used in sunscreens without any problems, just as neutral oil (a lipid based on coconut and palm kernel oil. INCI name: caprylic / capric triglycerides) and squalane (derived from olive oil).
Oils prone to oxidative rancidity, however, should be avoided in sunscreen formulations: rosehip oil, evening primrose oil or pomegranate seed oil, hemp, elderberry or black currant seed oil. As a rule of thumb, all these oils are basically seed oils!
In day care moisturizers with a sun protection, a small amount of these oils may be present (up to 10%), if the basic lipid matrix consists of stable oils.
Organic cosmetic manufacturers are usually using such a stable base of UV-resistant oils for their sunscreen preparations: jojoba, coconut, avocado, almond, high oleic sunflower oil, sesame oil, vegetable butters and waxes.
However, sometimes you‘ll find refined oils in their products as well: Oxidative fatty acids and impurities such as phospholipids have been extracted to prevent any kind of phototoxic reaction.
Unsaturated seed oils or essential oils are usually listed down towards the end of the list of ingredients. This means that the sunscreen contains only a proportionally small amount of oils prone to oxidation. In addition, antioxidants such as vitamin E (tocopherol) protect the emulsion. If you find one of the following seed oils mentioned in the upper part of the ingredients list of a sunscreen, you‘d better leave it on the shelf:
- hemp oil (cannabis sativa),
- rosehip oil (rosa mosqueta, rosa canina, rosa rubiginosa),
- evening primrose oil (oenothera biennis),
- borage seed oil (borrago officinalis),
- grape seed oil (vitis vinifera),
- black currant seed oil (ribes nigrum),
- elderberry seed oil (sambucus nigra),
- inca peanut oil (plukenetia volubilis),
- pomegranate seed oil (punica granatum),
- essential oils.
… aaand that’s enough for Day 1. We’ll sit and let that digest and you can read Part 2 on Wednesday (don’t worry – it will include specific recommendations for safe, natural sunscreen brands for acne prone skin!)
Click Here to read Part 2!