Kris’s question…I am noticing that plant stem cells are popping up in a number of skin and hair care products recently. I cannot find much info as to any efficacy beyond marketing information from the companies of said products. Any information is appreciated!

The Beauty Brains respond:

Like bow ties in Dr. Who, stem cells are cool.

Why stem cells are cool

Stem cells are unique because a) they are able to create more of themselves (they have the property of self-renewal) and b) they are able to turn into other cells (they have the property of differentiation). Therefore these cells are able to play a major role in tissue development, regeneration, and cellular renewal. In adult skin, some stem cells are located in hair follicles where they can create new cells to regenerate the epidermis or the hair follicle itself. Other stem cells live in the dermis where they support collagen production. (Check out FutureDerm for a more thorough summary including diagrams.)

The primary plant stem cell extract used in cosmetics is an apple extract known as Malus Domestica. The hypothesis is that, when applied to skin, these plant stem cells somehow signal or otherwise interact with our own skin stem cells and make them more productive.

What do plant stem cells do for skin and hair?

A review of Pubmed for peer-reviewed scientific studies on plant stem cells revealed dozens of entries, however they all have to do with botany. We could not find a single study documenting the effect of plant stem cells on human skin or hair. Similarly, a search in the database for technical articles published for the cosmetic industry (the Journal of Society Cosmetic Chemists) reveals no such study. Therefore, we have to rely on data provided by the companies that sell plant stem cell extracts.

Research from companies selling this extract show two basic things: when tested in the lab (in vitro) it has high antioxidant properties which can protect stem cells from UV-induced free radicals. When tested in people (in vivo) it can reduce fine lines and wrinkles. Here’s where we run into the same problem that many other alleged anti-aging ingredients have:

• There’s no proof that the ingredient works on skin the same way it works on cells in the lab.
• The testing that was done on real people only shows an anti-wrinkle effect which can be achieved by moisturizing or film forming ingredients.
• There was no control included in skin study so we don’t know how much of the anti-wrinkle effect comes from the plant stem cells and how much comes from the cream that it was contained in.

In addition, if the mode of action is indeed protecting stem cells from UV-induced free radicals, then why wouldn’t an ordinary sunscreen have the same effect? It would certainly be much cheaper.

The Beauty Brains bottom line

Plant stems cells are certainly intriguing and the research done so far shows they may have beneficial properties. But the companies selling such products haven’t demonstrated (to our satisfaction at least) that they’re worth the cost.

Image credit: http://upload.wikimedia.org/

Traci asks (via FaceBook)…Can’t Quaternium-15 be a skin irritant?

The Beauty Brains respond:

Quaternium-15 is a formaldehyde-releasing preservative commonly used in cosmetics. (We recently mentioned it in our post on Aveeno Daily Moisturizing Body Wash.) But is it safe?

Pros and cons of a preservative

Quaternium-15 is sold in a variety of forms and is commonly used because it’s very effective against a broad-spectrum of microbials including bacteria, fungi, molds. In addition it is cost effective and easy to formulate with. However, a number of studies have shown that it can cause allergic contact dermatitis. If you’d like more background, Dermnet  has a nice explanation how some individuals may become sensitized to formaldehyde containing materials and may have a reaction to Quaternium-15.

Quick research review

Bad: One study (E. Warshaw, et al. Contact dermatitis of the hands: Cross-sectional analyses of North American Contact Dermatitis Group Data, 1994-2004. Journal of the American Academy of Dermatology, Volume 57, Issue 2, Pages 301-314) found that it was responsible for over 16% of about 1000 allergic contact dermatitis cases studied.

Good, sort of: The “Final Report on the Safety Assessment of Quaternium-15″ published in the International Journal of Toxicology  says Quaternium-15 “is not a primary skin irritant in humans” but  may be a human sensitizer in some clinical patients. It safe at concentrations “not exceeding those presently in use.”  (0.1% to 1.0%)

Good and bad: The Scientific Committee on Consumer Safety SCCS OPINION ON Quaternium-15 reviewed multiple tests: One concluded that  a 10% dose of Quaternium-15 did not cause allergic sensitization in a Guinea pig study  and therefore, was “not considered to have a significant potential as a human skin sensitizer. Another test, on humans, showed that at  0.6% in petrolatum the preservative did not induce allergic contact dermatitis. Yet, two other studies showed Quaternium-15 was “a potential human skin sensitizer under these test conditions” and that up to “10% of the population had a positive reaction” to this material and that it “can be an allergen for many people.”

The Beauty Brains bottom line

While the data is mixed, studies have certainly shown that some people are sensitive to Quaternium-15. Problems usually occur when the ingredient is used at high level and held in contact with the skin for long period of time. Most people have no problem with this ingredient when used at the  lower levels typically found in cosmetics, especially if these are rinse off products. If you find yourself with symptoms of allergic contact dermatitis you should check the ingredient lists of your cosmetics for Quaternium-15.

Image credit: http://upload.wikimedia.org/

We’ve reported on several interesting beauty science stories over the last week or so on Twitter and Facebook so we thought we’d collect the links here for your reading enjoyment:

Can your clay facial mask fight infection?
Researchers have found that metal ions in certain types of clays could fight deadly staph infections.

False eyelash adhesives can cause bad reactions
The American Academy of Ophthalmology (AAO) says these adhesives can cause eye infections, eyelid swelling, even permanent loss lashes swelling.

Are lotions with gold nanoparticles causing skin aging? 
Despite the provocative headline, this may not be as big a problem as you think.

Oxygen in skin care products is Beauty BS!
FutureDerm explains what oxygen can (and can’t) do in cosmetic products.

Are you allergic to your smartphone? 
Smartphones can contain nickel which for some people is a powerful sensitizing agent. Does your face get irritated where it touches your phone?

We recently received a comment on our post about the world’s top 5 skin moisturizing oils which reminded us how faulty logic can spread misinformation. Here’s the comment:

“Mineral oil? Aww HELLLL NO. This is absolutely the worst thing you can put on your face, it is used in motor oil! MOTOR OIL!”

This statement is reminiscent of the warning we used to see about using sodium lauryl sulfate which went something like this:

“Sodium lauryl sulfate is bad for your face and skin because it’s used in garage floor cleaners.”

Or here’s another one we just made up:

“You drink water? Don’t you know that water is also used in cyanide poison?  Gasp! CYANIDE POISON!!!”

Do you see the faulty logic in all these statements?

Logical fallacies

Even when both premises of an argument are true (water is in cyanide and cyanide is bad for you) the argument may still be wrong if the logic employed is faulty. There are several types of faulty logic, or logical fallacies. For a great explanation, check out the article by the Skeptics Guide to the Universe on the Top 20 Logical Fallacies.

In our particular example it appears that the logical fallacy is known as “Confusing association with causation.” It’s not the water that makes cyanide dangerous, it’s the hydrogen cyanide gas that’s dissolved in water that’s the problem! Similarly, it’s not the mineral oil that makes motor oil bad for your skin or SLS that makes garage floor cleaners too harsh. There are other factors at work which are ignored by the person making the faulty argument.

Don’t get us wrong: If data proves there’s a legitimate safety issue with a cosmetic ingredient, then of course that information should be brought to consumers’ attention. But using logic fallacies to make spread misinformation doesn’t help consumers or the cosmetic industry.

The Beauty Brains bottom line

Don’t fall for faulty logic when considering what’s safe and what’s not safe for your hair and skin!

Image credit: marciokenobi.files

Aveeno Daily Moisturizing Body Wash is the number two best selling beauty product on Amazon.com this week (because it’s on a special promotion.) Let’s look at the label to see what makes it moisturizing.

Aveeno Daily Moisturizing Body Wash ingredients

Water
Solvent for the other ingredients. Is it a moisturizer? I suppose so but you’re already in the freaking shower where there’s plenty of water.

Glycerin
Is this moisturizer? Sure when it’s left on skin. It doesn’t really do much when rinsed off from a body wash. Unless maybe it’s moisturizing the shower drain. (Hey, that’s a new product idea for the folks that make Drano!)

Cocamidopropyl Betaine
Is this ingredient moisturizer? Now we get close to the true moisture story of this product. This product really moisturizes by not drying out the skin. It does that by using mild cleansing ingredients like this one that don’t strip natural oils.

Sodium Laureth sulfate
While not at the top of the mild cleanser list, the laureth version is milder to skin than sodium lauryl sulfate.

Decyl Glucoside
Now that’s more like it. Glucosides are very mild and reasonably good foamers.

Avena Sativa (Oat) Kernel Flour
Well it wouldn’t be an Aveeno product without some oat extracts now would it?

Glycol Stearate
A pearlizer ingredient added to make the product look more moisturizing.

Avena Sativa (Oat) Kernel Extract, Avena Sativa (Oat) Kernel Oil, Soja (Soybean) Seed Oil, Helianthus Annuus (Sunflower) Seed Oil
More natural goodies that make the ingredient list look better.

Sodium Lauroampho PG Acetate Phosphate
Another mild cleanser that has some skin conditioning properties.

Guar Hydroxypropyltrimonium Chloride
This one’s a keeper. It’s a positively charged conditioner that sticks around even through rinsing.

PEG 120 Methyl Glucose Trioleate
A baby shampoo type mild cleanser.

PEG 150 Pentaerythrityl Tetrastearate
A thickening agent. Since this is a mild formula that doesn’t contain a lot of strong anionic detergent it can’t be thickened with salt like many body washes and shampoos.

Hydroxypropyltrimonium Hydrolyzed Wheat Protein Hydroxypropyltrimonium Hydrolyzed Wheat Starch
Since these are quaternized they can stick to skin and help condition. Provided of course they put enough of the stuff in the formula.

Tetrasodium EDTA
A chelating agent it’s part of the preservative system.

Quaternium 15
The primary preservative.

Fragrance
Smelly stuff.

May Contain (+/-):, Sodium Hydroxide, Citric Acid
These are adjusting agents that are only used if the pH is too high or too low.

If you care to purchase Aveeno Daily Moisturizing Body Wash please support the Beauty Brains by using our link. Thank you!