Sunscreen: Chemical vs. Physical

Sunscreen (sunblock, suntan lotion, sun cream or what ever else you have heard it called) is meant to protect your skin from potentially harmful UVA and UVB rays. These ultraviolet rays are what cause sunburn. Most sunburns are the result of overexposure to UVB rays (260-320nm in sunlight).

For maximum protection from UV rays, it is important to apply sunscreen about 20 minutes before you go outside, and to reapply it every two hours. However, if you are going in the water, you should apply more often as water resistant sunscreens only protect for between 40 and 80 minutes.

There are two different types of sunscreens: chemical and physical.

Chemical:

Chemical sunscreens contain ingredients that actually absorb UV rays. Some common ingredients in these sunscreens are avobenzone, oxybenzone, Tinosorb M, Tinosorb S, Mexoryl SX, and Mexoryl XL. These ingredients absorb harmful UV rays and convert them into harmless energy. Ingredients like Tinosorb M and S and Mexoryl SX and XL protect skin from both UVA and UVB rays.

If you plan on using sunscreen containing avobenzone make sure that it also contains a stabilizing ingredient like octocrylene. Avobenzone needs to be stabilized because it degrades when it comes in contact with sunlight. About 56% of beach and sport sunscreens contain oxybenzone according to the Environmental Working Group (EGW).

Many toxicology experts believe that oxybenzone is an unsafe ingredient that can lead to hormone disruption and cell damage. Here is an article discussing exactly that. It is suggested that children avoid using sunscreens containing oxybenzone until more research is done.

Physical:

Physical sunscreens usually contain particles of zinc oxide or titanium dioxide which sit on the surface of your skin and deflect UV rays. The size of these ingredients is usually 20 to 200 nanometers.

A possible problem with this type of sunscreen, according to new research from the Missouri University of Science and Technology, is that a chemical reaction happens when zinc oxide is exposed to sunlight. This chemical reaction produces free radicals that may increase risk of developing cancer because these unstable molecules can cause damage to cells and their DNA as well as kill them entirely. The longer zinc oxide is exposed to the sun, the more it can cause damage to cells. However, the scientist who conducted this research, Dr. Yinfa Ma would "still advise people to wear sunscreen. Sunscreen is better than no protection at all."

Today, sunscreen is available in both creams and sprays. However, the EWG does not endorse the use of spray-on sunscreen as the nanoparticles of these metal oxides can be inhaled and their effect on our bodies is not yet known.

So if so many of the ingredients in these sunscreens are potentially bad for our bodies, what should we do?

Interestingly enough, different foods can actually increase your internal sun resistance. Foods containing a lot of antioxidants as well as super foods help with this. Astaxanthin, a dietary supplement, contains fat-soluble carotenoids that are carried to skin cells to protect the cells from UV exposure. There are also natural sunscreen products for sale, although the FDA does not allow them to be labeled as sunscreen, that may be safer for your skin!

Katie Rigdon

Sources:

http://news.mst.edu/2012/05/sunscreen_ingredient_may_pose.html

http://www.medicalnewstoday.com/articles/176441.php

https://www.pharmacymix.com/physical-vs-chemical-sunscreens.htm

http://www.naturalnews.com/032815_sunscreen_chemicals.html

How do skin lighteners work? Arbutin's role in cosmetics

At one point or another we've all seen our mothers or grandmothers dabbing their face with cream. Look inside their purse and you'll find a small container called "Skin Lightening Cream" boasting to "get rid of all your dark spots to make you look 10 years younger!" Have you ever stopped to ask yourself just how these creams can lighten your skin? Well many utilize a chemical called arbutin to aid in this effort. Arbutin inhibits the enzyme tyrosinase - an enzyme that controls the synthesis of melanin. Inhibit this enzyme and produce less melanin, thus making less pigment and lightening the skin.

Structure of tyrosinase 

Simply put, arbutin is a chemical with a glucose attached to a hydroquinone - an organic compound featuring two hydroxyl groups bonded to a benzene ring.

Arbutin - glucose and hydroquinone

Hydroquinone

However, it is important to understand that there are different types of glycosidic bonds between the glucose and hydroquinone that produce different behaviors of the chemical - namely, alpha and beta. Beta is the one that occurs naturally in the bearberry plant from which arbutin is extracted. Glucose residues in cellulose are bound by beta glycosidic linkages while glucose residues in starch are bound by alpha glycosidic linkages. Naturally extracted "beta" arbutin is common among the world of cosmetics while the "alpha" arbutin can only be produced in laboratories. 

A common point of contention among scientists today is "Is new always better?" Yes, we've have managed to engineer an alpha arbutin - but is it necessarily better than the naturally occuring beta? In fact, it would be false to suggest that merely because it is new it provides better suppression of melanin than the beta while staying just as safe as the naturally occurring arbutin. Until full toxicological tests are performed on the new chemical with positive results should the shift be made towards the new alpha arbutin as the most common skin lightening agent. It is in the opinion of Hannah Sivak, PhD that "novelty in a chemical is not an advantage but a problem."

Source: http://www.skinactives.com/blog/2011/04/28/guide-what-is-arbutin-the-most-common-skin-lightener/


andrew kang 

Debunking the Myths - Sodium Lauryl Sulfate

You may have seen this ominous email floating around in your inbox somewhere:

Source: snopes.com

But take the warning with a grain of salt, as not everything in this email may be true... First of all, there is an inherent error within the email chain. It states Sodium Laureth Sulfate, and abbreviates it to SLS, while SLS is actually Sodium Lauryl Sulfate, and the abbreviation for Sodium Laureth Sulfate is SLES. The difference between the two compounds is small, with just an additional ether group in SLES. SLES tends to be a little less irritating to the skin, but other than that, the compounds are pretty much the same.
But with that little bit of snarkiness aside, let's take a closer look at the compound in question:

Sodium Lauryl Sulfate

Structure of Sodium Lauryl Sulfate

SLS is an anionic synthetic detergent, which means that it is a long carbon chain to which a sulfate group (-SO4) is attached, forming the negatively charged (anionic) part. The 12-carbon tail attached to the sulfate group gives the material its amphiphilic properties, or both water loving and water hating. The carbon end of the compound is the nonpolar, hydrophobic side, while the sulfate side is the negatively charged, polar, hydrophilic part. Amphiphilicity is required of detergents, because it needs to be water hating, so it can attach to the oils and greases to be removes, and water loving, so it can be rinsed off easily with water. This property is what makes SLS so abundant in things like shampoos and soaps etc.
However, SLS still does pose some threats. SLS has been found to have many side effects, such as:

• Eye, skin and mouth irritations
• Membrane alterations
• Harmful to the brain, heart, spleen, liver
• Chronic irritant contact dermatitis
• Harmful to normal cell function
• Corrosive to hair follicle, and can cause hair loss

With a rap sheet like this, you might wonder why SLS is used in virtually all shampoos, toothpastes, mouth washes, and more. Well while the above may be true for SLS, the concentration of SLS in these common products is too low to make a difference. Also because our skin only comes in contact with the products for a short amount of time, it doesn't affect it in any noticeably way. As long as you don't marinate your scalp in it every night, SLS will not cause any harm. 

Even if all these harmful effects were possible of SLS, nowhere on that list is "carcinogen". So how did the myth of SLS being a carcinogen come to be?

Back in the 70s, due to sketchy manufacturing processes, small amounts of nitrosamines, which are carcinogens, entered into the shampoos. Somehow, the dubious rumor began that SLS reacted with formaldehyde to make nitrosamine. However, anyone with half a brain can figure out that since first of all, nitrogen is absent in both of those compounds, there is no way to put them together to make a nitrogen containing compounds

It would take some pretty strong, black magic to make this reaction happen

SLS + Formaldehyde --> R¹N(-R²)-N=O???

Therefore, the myth that SLS is a cancer causing compound found in shampoos is FALSE. While it is true that it can be a potential skin irritant, and have dangerous side effects, we are not exposed to it for a long enough time and at a high enough concentration for it to actually affect us. So by all means, continue lathering away with your safe shampoos and soaps!

jennymu

Antioxidants and Aging

In the cosmetic world, anti-aging creams are popping up with increasing frequency. They claim to make you look decades younger by removing wrinkles, spots, and giving you a youthful glow. Seems like a miracle to me. Such miracles don't come cheap either, with prices in the hundreds being average. Is a jar of this anti-aging cream worth it, or is it just empty promises in a nice little package? We'll take a closer look at one of the major contributors of aging, and how cosmetic companies combat it.

Oxidative stress is one of the leading causes of aging signs, so it makes sense that many cosmetic companies try to target this when developing anti-aging products. This post will give more insight into what oxidative stress is, and the method by which these companies try and reduce it.

Here is a helpful introductory video:

The human body needs a balance in redox reactions. "Redox" is a scientific term used to describe chemical reactions that involve the addition or reduction of electrons to molecules, thus altering oxidation numbers or "oxidation states". Reduction is adding electrons to an atom, and oxidation is removing electrons from an atom. The result of this change can be destructive (think rusting iron, a commonplace example of oxidation). Therefore, oxidative stress is basically an imbalance between the production of free radicals, the oxidizing agent, and antioxidants, which are reducing agents. When there are too many free radicals to be reduced by the antioxidants, this creates oxidative stress within the body.
Free radicals are electronically unstable atoms or molecules capable of stripping electrons from any other molecules that they meet in an effort to achieve stability. In their wake, they create even more unstable molecules that attack their neighbors in a domino-like chain reactions. This causes extensive damage to the cells.
Disturbances in this normal redox state in the body can cause toxic effects due to the production of free radicals that will inflict molecular damage to the proteins, DNA, lipids, and other biomolecules in your body, in a process called "oxidative stress". Oxidative stress basically is an imbalance between the production of free radicals, reactive oxygen species,  and antioxidants defense species. This way, the free radicals, the oxidation part, end up overwhelming the antioxidants, which are reducing agents, and so we see oxidation of important molecules such as proteins, lipids, etc.
This oxidative stress can lead to premature signs of aging, one of the biggest fears most women have.

Premature aging: a woman's biggest fear

It seems intuitive, therefore, that one of the best ways to fight these free radicals is to up the amount of antioxidants. These antioxidants are able to neutralize the free radicals, and prevent them from damaging the cells in your body. While many creams include antioxidants in their extensive list of ingredients, is topical application really the best way to go? A 2011 study investigated this very question. The study looked at antioxidant levels in the skin after using them both topically and systemically. 129 healthy women, aged between 21 and 72 years, were divided into seven groups and given topical creams, oral supplements, both, or a placebo. Ultimately, the oral supplement group had the best results, sometimes even beating out the group that had both topical and oral. The human skin is a difficult barrier to penetrate, in order to keep out all the germs that cause diseases, and sometimes this can work negatively when it comes to things like antioxidants. Therefore, the best way to go about getting your daily dose of antioxidants is orally, through food.

Foods rich in antioxidants

Sources: 
http://www.sciencedirect.com/science/article/pii/S0923181110000782
http://www.ccjm.org/content/73/12/1049.full.pdf
http://www.wiley.com/college/boyer/0470003790/reviews/redox/redox.htm
http://www.healthchecksystems.com/antioxid.htm

jennymu

Crash Course on Parabens!

You may have seen the name while reading the back of your shampoo bottle in the shower, or your toothpaste tube while brushing your teeth, and this is not surprising, considering the fact that parabens are in a majority of common household items.
Parabens are used to prevent the growth of microbes in cosmetic products, and can be absorbed through the skin, blood, and digestive system. Parabens actually are several distinct chemicals with a similar molecular structure. The general chemical structure of a paraben, or a para-hydroxybenzoate, is:

 where the R is an alkyl group.

The most common forms are ethylparaben, butylparaben, methylparaben, and propylparaben. where the R group is an ethyl, butyl, methyl, and propyl respecitvely.

These compounds are found in well over 10,000 of the 25,000 products in the Environmental Working Group's Skin Deep database. Clearly, we have a lot of exposure to them in our day-to-day activities.
However, a 2004 UK study detected traces of parabens in the breast cancer tumors of 19 out of 20 women studied. This small study does not prove an actual relationship between parabens and cancer, but it did detect the presence of intact parabens that were unaffected by the body's metabolism. This is especially important because it shows that these compounds have the ability to penetrate the skin and remain within the body.
But once the parabens enter into the body, what makes them so dangerous?
Of greatest concern is that parabens are known to disrupt normal estrogen function, which can lead to breast cancer. They mimic estrogen and bind to the estrogen receptors on cells. They also increase the expression of genes usually regulated by estrogen, and these genes are what cause human breast tumor cells to grown and multiply in cellular studies.

Clearly, parabens are potentially dangerous compounds that are in a myriad of common cosmetic products. While there are concentration limits recommended for parabens in commercial products, these recommendations do not account for the use of multiple parabens in a single product or for exposure to parabens from several products by a single individual. Cosmetic manufacturers are seeking alternative methods to prevent microbial growth in their products, but for now, the cheapest and most effective method is parabens.What we can only do is make sure we are aware of the potentially harmful compounds in our products, and their effects. 
           A variety of cosmetics without parabens



jennymu

Lead in Lipstick?!

NBC Nightly News report on the results of an FDA survey of lipsticks! From February 12, 2012.

Visit NBCNews.com for breaking news, world news, and news about the economy

Check out this table to see the results of the FDA study in greater detail! Blog post to follow about heavy metals that might be in your cosmetics!

katierigdon

Nanocosmetics 101

Many young women will sympathize with the adage "Beauty is pain," but new studies show that perhaps it should be modified to "Beauty is risk." The applications of nanoscience in gold creams have previously been discussed, and it is time for a crash course for all prospective cosmetics buyers in Nanocosmetics 101.

Nanotechnology has edged its way into the cosmetics scene quickly and expansively. Currently, there are two ways with which nanotechnology is being utilized in the sphere of cosmetics: as UV filters and for delivery purposes.

Zinc oxide and titanium oxide have been used as UV filters in sunscreens. This is not news; the white stuff you see on lifeguards' noses at the beach is just zinc oxide in the form as we've known it: with a white, chalky appearance. Nanotechnology has created microscopic particles of these oxides that retain their UV-blocking characteristic with added benefits. Sunscreen is now transparent, less smelly and greasy, and more easily absorbed by the skin. The Body Shop, Nivea, and L'Oreal have all hopped onto the bandwagon and have released sunscreens and moisturizers using these nanoparticles.

In the past, liposomes and niosomes have been used as delivery vehicles in cosmetics. Nanotechnology, of course, has changed that. Solid lipid nanoparticles (SLNs) are nanometer-sized particles in a solid lipid matrix. They protect the encapsulated ingredients from degradation Their occlusive properties also make them ideal for day creams. Liquid nanoparticles have also been developed, which have proven even more useful in some cases. Nanostructured lipid carriers (NLCs) have a higher loading capacity and long-term stability compraed to SLNs as well as boasting better accommodation for active ingredients. For the aesthete's purpose, however, NLCs have been known to give a more whitish appearance as opposed to yellow. For both nanoparticles, increased skin penetration is a benefit that isn't easily overlooked.

As this blog seems to be concerned with adages, let it be said that "Every rose has its thorn." Certain health risks have been speculated with the use of nanoparticles. Fullerenes, which are nanoparticles used in anti-aging products, may be potentially toxic if able to penetrate the skin. Nanoparticles in sunscreens, too, may be able to breach sunburned skin. When shrunk down to a nanometer-scale, certain materials have been known to display new and unusual properties. For this reason, nanotechnolgy in cosmetics has been brought to the attention of health organizations everywhere and are being studied for possible adverse effects. A new law passed by the EU will make it mandatory for products to be labelled as 'nano' if they contain nanomaterials. This should be an indication as to how far-reaching nanotechnology has become in the world of cosmetics.

Of course, these risks are still in the process of being corroborated by researchers and the benefits seem to stack up quite high against the potential dangers. The consumer should always be conscious of the products he or she is buying and when shopping for products labelled 'nano,' must take everything into consideration. Nanotechnology has a bright future in the world of cosmetics and can have far-reaching applications in all fields.













References: "Nanotechnology in Cosmetics". Observatory Nano, Apr. 2009. Web. Retrieved from: http://www.observatorynano.eu/project/filesystem/files/Cosmetics%20report-April%2009.pdf




andrewkang

Gold Face Creams?

Recently, there has been a lot of hype over the new fad of having gold particles encapsulated in various skincare products. But does this actually have any effect? or is it just a costly stunt introduced by cosmetic companies looking to charge a few extra bucks by labeling a product with gold.



Well the Chantecaille Nano Gold Energizing Creme, priced at a hefty $420.00, touts its "nanoparticles of 24-karat gold [which] are bound to silk microfiber, a natural protein that is moisturizing, antioxidant, and anti-inflammatory. Through nanotechnology, these elements reach the cellular level where they act as the ultimate healing and preserving force."

While this description may sound promising, the science behind it is a little shady.

There are a few truths behind the advertising. The nano-sized particles do have the ability to penetrate the epidermis of the skin much more effectively than say, simply gold flecks, but once the gold gets under the skin, does it really have an effect?

While there is no concrete evidence of the benefits touted by the cosmetic companies, there maybe evidence of some potential dangers associated with nanoparticles. Gold nanoparticles have been shown to be toxic to certain cells in the laboratory setting. While some cosmetic companies claim the amount of gold nanoparticles within these cosmetics is too small to really make that much of a difference.

At the same time, the small amount of gold nanoparticles in the cream is too small to be of any benefit as well, should there even be benefits in the first place, which still remains disputable.


jennymu