Are lotions with water bad for your skin? Episode 157

Are lotions with water actually bad for your skin?pool-519453_640

Veronica asks…I heard that using lotions with water is actually bad for your skin because as the water evaporates it removes the skin’s natural moisture and oil. Is this true?

Veronica’s question is an interesting twist on a theme that we have discussed a couple of times – and that is how moisturizers actually work.

There are two fundamental ways that lotions can moisturizer your skin: one way is to provide an occlusive barrier that prevents the moisture that’s already in your skin from evaporating. That’s what ingredients like, petrolatum, mineral oil, silicones and so forth do. The technical term for this is reducing TEWL or Transepidermal Water Loss.

The second way lotions work is to attract moisture to you skin using an ingredient that has an affinity for water. We call these ingredients “humectants” and they are things like glycerin, sorbitol, and hyaluronic acid. They essentially bind water to the surface of your skin.

The best skin moisturizers use both mechanisms to moisturize skin. And the best way to do that is through an emulsion that’s a combination of oil and water.

This brings us back to Veronica’s question – what about the water that’s contained in the cream or lotion? What does it do?

There’s enough water in a lotion or cream to give your skin a little quick moisture boost which the oils and other occlusive agents can lock in your skin. Let’s be clear – most of the moisturizing effect comes from preventing the loss of what’s already in your skin, but it doesn’t hurt to add that extra little topical boost of moisture.

Right, some of that extra water will be absorbed by your skin and some of it will evaporate but that process of evaporation doesn’t cause any harm to your skin. It’s not going to cause the loss of skin’s natural moisturizing capacity in any way. So what Veronica has heard about lotions is just a myth. BUT I can see where this myth may have got its start.

It could have come from the fact that soaking your skin in water is not good for it. That swells the skin cells and does allow leaching out of some water soluble moisturizing components like urea and sodium PCA. But that only happens when your skin is submerged in water for a considerable period of time.

So I could see some clever marketer taking this little half truth and then saying that skin care products that contain water are bad for skin so they can sell you their special oil based product that doesn’t contain water. But it just doesn’t work that way. So, Veronica there’s nothing to worry about from using skin lotions that contain water.

Is air drying hair more damaging than blow drying?

DaniD in our Forum says…I recently came across this article claiming that air drying is actually bad for your hair. “The reason? When hair comes into contact with water, it swells which damages the protein. The longer your hair is wet, the longer it swells and the greater the chance for damage.” Is this true? I also wonder if all the extra tugging from brushing during blow drying could add additional damage as well.

We wrote about this a couple of years ago. I think the post was lost when our server crashed. I can’t remember if we ever talked about it on the show before or not. But, yes, there is showing that air drying your hair does cause some damage. The mechanisms is exactly as you explained.

That swelling and shrinking process she described is actually called “Hygral Fatigue.”

Exactly. But the study that we found didn’t compare this damage to the damage caused by blow drying, so we don’t have data to say which is worse. If I had to choose, I’d say that blow drying is more damaging for 3 reasons:

1. You still get some fiber swelling whether your blow drying or air drying.

2. The additional heat from blow drying can be damaging by itself.

3. The tugging that she described does cause additional damage.

I think it’s really interesting, and kind of counter-intuitive, that air drying causes any damage at all but it’s probably still better than blow drying. But you know what doesn’t blow…the fans who review us on iTunes.

Can tomatoes really shrink your pores?

Renee asks…According to, rubbing tomatoes on your face is a good way to shrink your pores, is that true?

Let’s take a look and see exactly what Easyhacker says about using tomatoes on your face. According to the video on their website: “Tomatoes are rich in vitamin C and acids, both of which are effective at reducing the appearance of pore size.”

There is a kernel of truth to this: In the video the author mentions that the acid in tomatoes is salicylic acid. Salicylic acid is a keralytic agent which means it can loosen dead skin cells. This is one way to keep pores clear of debris and keep them from appearing larger. So yes, sal acid is good for minimizing pores. But do tomatoes contain enough of it?

Tomatoes contain about 1mg of sal acid per 100 gr which about 0.01%.
Salicylic acid products that are effective against acne need to contain about 3% sal acid. So tomatoes are about 300 times weaker than a product that you can buy over the counter. I really can’t see how that small of an amount of sal acid would have much effect.

You can do the same kind of calculation for vitamin C. Tomatoes contain about 23 mg of ascorbic acid per 100 gr of the fresh fruit. That’s about 0.23%. We know from previous research that the most effective level of vitamin C is somewhere between 15% and 20%. That’s almost 100 times too low.

The bottom line: Tomatoes do contain natural chemicals that can help keep your pores clean. However, they contain FAR less than products that are optimized for this purpose.

Beauty science news

FDA Recommends Limiting Lead In Cosmetics


Lead is NOT a cosmetic ingredient that is added to the product for any reason whatsoever. Rather it is a contaminant that occurs naturally in the environment that comes in in trace amounts with certain ingredients.

It’s difficult if not impossible to remove all lead from any given product depending of course on what ingredients you’re using.

This hit the news pretty hard a few years ago when I believe there were two studies showing that many brands of lipstick, especially those with red colors, do contain small amounts of lead.

The amount of lead ranges from a couple of parts per million two up to about 9 ppm.
We’ve also said before that such small amounts don’t seem to really present much of a risk because your body can process these. Now for very young children or pregnant women even smaller amounts do raise some concerns but remember that small amounts of lead are approved even in drinking water and candy. So limiting lead to very low levels is a prudent thing to do and it should be done but getting to absolute zero doesn’t always seem to be necessary or feasible.

So the new news is the FDA has said they want to limit the amount of lead in cosmetics to 10 ppm. What does this mean?

Since the highest amount of lead that was found in the study a lipsticks was 9 ppm the FDA is really just saying make sure you don’t go any higher than what we’re already finding in your products.

The bottom line is that’s a good safeguard but it really doesn’t change much in terms of what’s already in the products you’re using.

Dumpster diving for luxury makeup


Have you heard about the latest strategy for getting beauty products? It’s dumpster diving. According to a story in Marie Claire, Beauty bloggers, and other motivated people I suppose, are heading out to the dumpsters behind stores like Sephora and Ulta and finding discarded beauty products. These stores probably have to throw away old product and testers to make way for the new stuff and some less-than-squeamish beauty aficionados are diving into those dumpsters to retrieve what they see as perfectly fine products.

One beauty vlogger posted a video in which she found nearly $2000 worth of product in an Ulta dumpster. And since the video has over a million views no doubt this will inspire some other people to take the dive.

In the story they also got quotes from a guy in New Jersey who has been reselling found make-up since the 1970’s. He says he makes 100 percent of his income from beauty product dumpster diving. So, if you’re buying things on eBay or Craigslist, well…sometimes a good deal might not be such a good deal.

So you might be wondering whether this is safe. It really depends on the product and the risk you’re willing to take.

Aloe free aloe


I just talked about lead, a contaminant you don’t want to have in your products but it’s there. Here’s a story about an ingredient that you DO want in your products but it seems to have gone missing.

Bloomberg News reported that some private label brands of aloe vera skin care lotions that are sold by Walmart, Target, and CVS didn’t actually contain any aloe vera. Bloomberg commissioned a lab to test samples of these products and low and behold, they couldn’t find any traces of aloe. Which makes me think…Bloomberg has got a LOT of time on its hands.

If you go back to episode 156 you’ll find out why this is kind of much ado about nothing because except in a few rare cases aloe doesn’t really do anything in the skin lotion anyway so if you’re missing it you’re not missing much.

Still, no one likes to be deceived. Companies should be held responsible for deceptive advertising. If they’re selling you an aloe lotion you should expect to find aloe in it. (Unless it’s just aloe scented which we’ll get to in a second.)

But here’s the piece that makes no sense to me. It’s very common in the beauty industry to sell a product with a featured ingredient in this case aloe and that product only contains a very small amount of aloe or maybe it only smells like a aloe. There is no law on how much you have to put in your product so you put in a small dusting of aloe you call it an aloe product and you’re done. That’s perfectly legal. Why would you risk a lawsuit and even action by the government by lying on your label and saying it contains aloe and it doesn’t. You’re not saving any time or money. It makes no sense!

Now I should point out that the test method used by the lab to measure aloe is a bit controversial it’s not 100% accurate so it’s possible these results could just be a fluke.

Taking more selfies makes you happier


According to a study published by researchers at the University of California-Irvine, they tested forty-one students who were instructed to take selfies for four weeks straight. They also had to share the selfies with others. They then reported their moods over that time. Researchers found that this group of people were happier and more confident over the course of the study. Just smiling (even fake smiling) made people feel better.

Now, I had to dig a little deeper because the report on this study was pretty weak and left open a lot of questions. Like did it have to be selfies or could just any picture do? Also, was there a control group.

Well, it turns out that there were actually three groups. One group took selfies, another group took pictures of things that made them happy, and the third took pictures of things that thought would make other people happy. Only the selfie takers reported feeling more confident and comfortable.

So, the bottom line is that this research suggests a good strategy for becoming more happy. Run every day and at the end take a smiling selfie. Then share it on twitter every day.

iTunes reviews

Breathe Easy 4 Once…Great fun for this med student — 5 stars. I appreciate their easy rapport, nerdball humor, and the SCIENCE. This podcast makes you a better consumer, science nerd, and human being. Okay, that last one might be a bit of a stretch but not by much. Keep it up! The world needs good podcasts like this to balance out the many shows about “Housewives of the Rich and Brainless.”

Cool Maven…5 stars. I realized that I have never before heard two highly intelligent men bicker and it’s very amusing. I’m a podcast freak and am very selective about those that I actually ‘subscribe’ to and they easily made the cut. THANK YOU, Beauty Brains — you ROCK!

Liz says… 5 stars. The Beauty Brains help you see through marketing claims and pseudoscience to make informed decisions and often save you money. Some may not like the banter at the beginning and throughout but I often laugh and enjoy it.

Look says… This is a great podcast to debunk a lot of beauty science myths and get to the truth of what’s in your bathroom. Really big fan though they tend to digress. They have a teensy blindspot about natural ingredients/ethnic hair care so I’d take their advice there with a pinch of salt.