It’s time for another Beauty Science poll and this time we have a theme: Know Your Nails. (I was inspired by the Right Brain’s post last week on coconut oil and nails.) Three of these statements about nail science are true; one is a clever forgery. Can you guess which one is the fake? Scroll down on the right sidebar to cast your vote.

Which statement is FALSE?

1. Toe nails grow about 50% slower than finger nails.

2. Finger nails grow faster on longer fingers.

3. If you’re right handed, nails  grow faster on your right hand.

4. Thicker finger nails grow more slowly.

If you aren’t sure or think you know, leave a comment and get hints from the Beauty Brains community.

Kitten Devine’s question…I’ve read your post about coconut oil being able to penetrate the hair and strengthen it. Now, since I’m looking for both something moisturizing for my cuticles and something to strengthen my nails Ive started to apply coconut oil to my nails and cuticles (only since yesterday, so I can’t tell if it’s working yet) so I wondered if it works the same way on nails as it does on hair? Can it penetrate the nailplate? And is it even possible for any product/ingredient to penetrate the nails and actually strengthen and condition them?

The Right Brain’s reply:

Thanks for a very intriguing question, Kitten. So far, we’ve not been able to find a definitive answer in the scientific literature but we did uncover a couple of interesting tidbits in the Journal of the Society of Cosmetic Chemists.

Nourishing nails

First, it is known that nails are more flexible when the water content is higher. And when you’re nails are more flexible they’re less likely to chip and break. But surprisingly, oil alone does not have much effect on nails. Researchers treated nails with mineral oil showed no increase in flexibility. But when they applied mineral oil to previously hydrated nails their flexibility was increased.  This finding suggests the oil itself is not strengthening the nail against breakage, but that the oil can lock in water.

Another experiment showed that an oil and water mixture (specifically a phospholipid-water preparation for those of you keeping score at home) did boost nail flexibility. The researchers theorized that oily material that can bind and seal water in the nails are helpful in improving flexibility (and therefore, strength.)

Second, the same article also pointed out that some materials can penetrate the nail but there was no indication that penetration and strengthening were connected.

The Beauty Brains bottom line

Oil can help keep nails moisturized and keep them strong by making them more flexible so they’re less likely to chip and break. But it appears that using lotion should be better than oil alone, unless you’re hydrating your nails first and then using oil to seal in the moisture.

Source:

J. Cosmet. Sci., 50, 363-385 (November/December 1999) Structural  characteristics  and permeability  properties of the human nail: A review GOURI V. GUPCHUP and JOEL L. ZATZ, College  of Pharmacy, Rutgers  University

What do YOU think? What’s your favorite nail treatment? Leave a comment and share your favorite nail treatment with the rest of the Beauty Brains community.

Charlotte’s concern: I went with my daughter and had a my first and probably only pedicure. After I had my pedicure I read a article that said you could get HIV from a pedicure. I’m worried. How true is this?

The Left Brain’s calming response:

While transmission is theoretically possible it is highly unlikely. According to this doctor, there have been no reported cases of HIV, Hepatitus B or C transmission from nail salons. Still, if you’re worried, I think you get tested by your doctor (the Oraquick Advance HIV 1/2 Rapid Test will give you a result in 20 minutes at your doctor’s office. You can take a Hepatitis screening as well.)

The real issue here is the cleanliness of your salon. While HIV transmission is not a serious concern, dirty implements and improperly sanitized foot baths can cause a variety of other infections. See our previous post about the danger of infection from pedicures for more details.

The Beauty Brains bottom line

There’s very little chance you’ve contracted HIV from your pedicure. But if you’re really concerned about taking your daughter to a nail salon, you might consider a Do It Yourself approach. See the links below for some of the basic tools you’ll need.

What do YOU think? Are nail salons safe or do you avoid them because of fear of infection? Leave a comment for the rest of the Beauty Brains community.

Patricia’s puzzled about polish: Does nail polish go bad or can it become contaminated? For example, you paint your nails once or twice and then don’t use it for a couple of years because you misplaced it, is it still safe!

The Right Brain nails the right answer:

If you’re looking for an excuse to splurge on a new bottle of OPI, we could tell you that you have to throw your old nail polish away after 6 months because it’ll spoil like a bottle milk on a hot summer day. But if you want to know the truth, we have to tell you that nail polish doesn’t really go bad.

Bacteria

Unlike water based cosmetics which are breeding grounds for bacteria, nail polish is pretty much self-preserving because of all the solvents it contains. (Not much grows in a ethyl acetate cocktail!) Just look at the major ingredients in an OPI nail polish: Butyl Acetate, Toluene, Nitrocellulose, Ethyl Acetate, Tosylamide/Formaldehyde Resin, Dibutyl Phthalate, and Isopropyl Alcohol. Nothing’s gonna grow in THAT chemical cocktail. You could say that nail polish is preservative free!

Dry Solvent evaporation

Of course just because it won’t grow bacteria doesn’t mean it can’t dry out. If you didn’t screw the cap on nice and tight before you lost the bottle two years ago, you can pretty much kiss your polish goodbye. Because those same solvents that won’t grow bugs will do something else: evaporate! And once nail polish dries out there’s not much that can be done to save it.

The Beauty Brains bottom line

While your polish may dry out quickly if you leave the cap off, you don’t have much to fear in terms of it spoiling because of old age. In fact, scientists predict that Hostess Twinkies and OPI nail polish will be the only things to survive a nuclear explosion. Oh wait a minute, that’s cockroaches. Well, never mind, you get the idea. And if you’re wondering about your other beauty products you might want to read our previous post on 4 Ways To Tell If Your Cosmetic Has Expired.

PS If you’re losing bottles of nail polish for years at a time, it sounds like you need a good makeup case!

What do YOU think? What’s the longest you’ve ever held on to a bottle of nail polish? Leave a comment and share your tawdry secrets with the rest of the Beauty Brains community.

Natasha needs to know: My principal banned black nail polish because he said it ruins your nails. So my question is does black nail polish really ruin your nails?

Sarah Bellum responds:
Natasha, I’m sorry to hear about your problem at school. The Beauty Brains would never question the authority of your principal, but what about the science behind his decision? That’s another story!

Yellow nails

It’s true that wearing dark shades of nail polish can stain your nails yellow. (Been there, done that!) That’s because there’s a reaction between the colorant and your nails. (The Left and Right Brains blogged about this before – go read their post on yellow nails.) But even if you do stain your nails, they’ll return to their normal color when they grow out. Other than the staining issue, I’m not aware of any other problems caused by black nail polish. Also, I believe that other dark colors can cause staining, so it’s not just about black.

Fashion sense or science?

Here’s what I don’t get: if the Principal is so concerned about nail health, why not ban all dark nail colors? Heck, why not ban acrylic nails? They can create problems too! Or, tell students they can’t get pedicures because they can cause infections. Why stop at black nails if health is really the issue here? Could it be that there’s another reason for the his decision? Could this be more related to school dress code than science? Hmmmmm. This makes me wonder how your Principal would look wearing OPI Black Onyx. But seriously, write back and tell us if you learn anything else from your Principal. We’ll present his side of the story too.

Has anyone ever got in trouble at school or work for using a certain kind of beauty product? Leave a comment about your larcenous behavior!