Do bath soaks really detox your skin? Episode 120

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Do bath soaks really detox your skin?bath-988502_960_720

Allison says… I have a question about bath soaks. I’ve heard a lot of buzz about mustard seed baths, epson salt baths, Dead Sea mineral baths, etc. Can taking a bath with any of these ingredients really help with detoxing your skin or absorbing nutrients?

Thanks for the question Allison first of all let’s get one thing clear: taking a bath in anything is not going to detox your body. That’s because your body doesn’t cleanse itself of toxins through the skin. That’s a popular misconception but it just doesn’t work that way.

Now having said that let’s look for evidence that a bath soak provides any benefit to your skin.

Let’s start with mustard seed oil. Mustard seed oil is rich in some essential fatty acids that are good for moisturizing skin. But A bath soak is a pretty poor way to deliver these kinds of ingredients. First, all that bathwater just dilutes them down and second the bath and only provides temporary exposure. That may not be enough time for the ingredients to penetrate into your skin. Essential fatty acids like the ones found in mustard seed oil would be more effective when delivered from a leave on cream.

So what about salts? Actually, this is a case where soaking in a tub MAY be best. At least according to a paper titled “Dead Sea Bath Salt for the treatment of psoriasis vulgarism.” The researchers treated 30 patients with psoriasis vulgaris, a condition involving rapidly dividing, over active cells that causes patchy, scaley skin. The patients were first evaluated using the Psoriasis Area and Serverity Index (PASI), a scale that indicates the intensity of the condition.
The patients were then divided into two groups: The control group were treated with common salt and the test group were treated with a Dead Sea salt mixture. The treatment for both groups involved soaking in warm, salty bath water for 20 minutes each day for a period of 3 weeks. At the end of the treatment, patients were assessed using the PSAI scale again.

The results showed that both types of salt water baths significantly reduced the extent and the severity of the psoriasis. However, the Dead Sea salt soak reduced the psoriasis a bit more. (However, the researchers point out that not all measurements reached a statistically valid level.) Still, this is some evidence that the Dead Sea salt mixture is better at reducing the effects of psoriasis. Why is this the case? No one knows for sure, but it apparently is related to proportion of magnesium, bromide and other counter ions contained in Dead Sea salt.

So, the bottom line is that soaking in bath salts can benefit certain dry skin conditions, such as psoriasis. But it won’t “detox” your skin.

Is this BB cream a good sunscreen?

Sarah says…I discovered a BB cream that’s a tinted primer with SPF 30. It would save me a step because I could use it as sunscreen and makeup in one. Do you think it could cover me enough for UVA damage?

The good news is the SPF for this product is based on titanium dioxide and zinc oxide so it will provide broad spectrum coverage and protect you from UVA. The issue is whether or not you would apply enough of the product to get the full SPF effect.

Most recommendations for sunscreen use that come from legitimate sources, like dermatologists, say you should use about an ounce to cover your entire body. This value is an extrapolation of the FDA’s guideline which says to use 2 mg per square centimeter of skin. Actually in 2011 the FDA revised their guideline and now they say to use two applications of 0.75mg of sunscreen per square centimeter of skin. But, everyone I’ve seen still references the single application of 1 ounce. If you break down that 1 ounce over your entire body it equates to about 1/4 tsp just for your face. (You’ll need to use about 1/2 tsp if you’re covering your ears and neck as well.)

This BB cream that Sarah asked about sells for $34 for 1 ounce. There’s about 30 mLs in an ounce and about 2.5 mLs in a 1/2 tsp. That means you’ll get somewhere between 10 and 20 applications out of a tube depending on if you’re covering your neck as well as your face. That breaks down around $1.75 to about $3.50 per use. That sounds really expensive to me! But if you really like the product that much, go for it as long as you apply enough.

Should you buy a hair steamer?

Meteor asks….I was looking online for a hair steamer. I did some research and found a site that said there are not many studies for hair steaming. Is this true?

In case you’re not familiar with that this process, hair steaming it is exactly what it sounds like. You apply steam to your hair because it supposedly makes it smoother, softer, and more moisturized. The practice is especially popular for natural hair. Typically this is done with a bonnet like device into which steam is pumped or from a handheld device that puffs steam directly into your hair as you comb through it. I assume the practice goes back much further but I remember seeing hair steaming units for the first in the 1970s .

This has such a commonsense kitchen logic to it that I’m surprised the beauty industry hasn’t exploited this idea more. There really aren’t very many hair steamers on the market. Why is that? Probably because it doesn’t work as well as expected. The idea that “injecting” your hair with steam is good for it doesn’t hold up scientifically. If you’re trying to moisturize your hair, just soaking in water works perfectly fine. Steam doesn’t provide any additional benefit in terms of getting moisture to penetrate more deeply.

In fact, too much exposure to high temperature steam can actually damage hair. There’s some classic research done by the hair care ingredient company Croda that showed when you apply a flat iron to wet hair you get little blisters or bumps in the hair shaft from, presumably from the steam evaporating. Granted, flat irons provide a higher temperature than just exposure to steam but still this could be an indication that heat and steam are not friends of your hair.


There hasn’t been very much written about hair steaming in the scientific literature but The Natural Haven blog does reference one study from 1934 that looked at the effect of steaming on wool fibers. (X-Ray Studies of the Structure of Hair, Wool, and Related Fibres. II. The Molecular Structure and Elastic Properties of Hair Keratin) In case you didn’t know wool is a pretty good surrogate for testing human hair. It’s not exactly the same but there is some overlap.

Anyway, the study wasn’t focused on hair care benefits but rather on manipulating the fiber for using it in fabrics. In particular they look at fiber stretching. The researchers found that if you take a wool fiber put a weight on the end of it and then expose it to steam, the fiber will stretch it out longer than its original length and it won’t shrink back afterwards. In other words the fiber was permanently straightened and lengthened. They hypothesized that the combination of heat and stress severed some of the disulfide bonds that control the structure of hair.

This might lead you to think that steaming hair could help provide a straightening fact help straighten out your curls however there’s two problems with that. First of all the time of steam exposure in the study was something like 15 hours. There’s no way you’ll be able to expose your hair to steam for that period of time. And secondly they only saw a straightening result when weight was applied to the fiber. Even if you’re brushing or combing your hair while you steam it it’s difficult to reproduce the effect of applying the force of a weight to each strand of hair. Also, I would think that since you’re not re-oxidizing the bonds to lock in the new straight configuration, there could be some reversion. Hard to say, again this isn’t very well studied.

My assessment is that steaming can’t replace chemical relaxing but that it may be enough to provide somewhat of a softening effect for tightly curled hair – maybe that’s it’s so popular in the natural hair community.

Is this tumeric-papaya mask good for skin?

Dafna asks…Have you heard of turmeric and papaya being good for your face? According to my facialist if you mix turmeric with yogurt and apply it as a mask you can get a good exfoliation. Papaya by itself, she says, also works well, in particular for comedones. Is any of this true? Should I listen to her or should I get a new aesthetician?

The answer is…some of it’s true. But not much.

Let’s start by talking about turmeric which actually comes from a plant that’s part of the ginger family. The commercial variety that’s used as a spice is extracted from little nodes on the root of the plant.

This extract is rich in compounds such as turmerone and curcumin and I did find some evidence that it has anti inflammatory properties. This could explain why traditionally it’s been applied to skin to help with wound healing. There’s also data which indicates that turmeric has antibacterial properties but I couldn’t find any evidence that it’s effective against p. acne which is the bacteria that cause comedones to become infected.

There’s no theoretical mechanism that I’m aware of that would make us believe that Turmeric is good for exfoliating. And the other thing to consider is that we really have no idea how these active components hold up over time and how much are still going to present in the jar of Turmeric you get at the store. If you were going to use this in some kind of do it yourself product you may be better off getting fresh roots and grinding them yourself.

Ok, so what about Papaya? Actually, papaya could be an effective exfoliant. That’s because it contains an enzyme called papain which does have a keralytic effect (meaning it will help loosen the adhesion between skin cells.) I found one study that tested papain at 1% and found that it’s quite effective at breaking down the dead skin cells of the stratum corneum.

The problem is that the papain is only present in significant quantities in green, unripe papayas. There’s not much in the ripe fruit. So it’s tough to know if the fruit contains enough papain to do any good. You can buy powdered papain which would be much more potent but you have to be careful because the enzyme can be irritating to skin.
So assuming you could get enough papain on your skin, would it be effective against comedones? I can’t find any specific research on this but it does makes sense because papain sort of does the same thing as salicylic acid which does help keep pores from getting clogged.

Also, papayas cost a couple of bucks each (at least here in the US) and maybe you’d get a couple of mask treatments out of each fruit. That means at best maybe you’d be spending about $1 per application. A sal acid cream is certainly more cost effective.

What’ s the bottom line for this turmeric and papaya mask? At best you have some folkloric stories and a weak theoretical mechanism for either of these ingredients really being good for your skin. It seems like a lot of work, and expense, to go through when there are alternatives that have been proven to work.

Is it safe to use phenyl on your hair?

Christy says…I came across RAVING reviews for Naissant Argan Oil Elixir on YouTube. There is an ingredient in this called Phenyl that I haven’t been able to find much information…aside from the fact that I’m guessing it MAY be Phenol and Carbolic Acid??? Everything about that states it is horribly dangerous. Can you please help me know about the ingredients regarding these ingredients?

One of the problems of podcasting is that it can be confusing to discuss homonyms. So I have literally spell somethings out for you.

First of all there when Christy says this product contains phenyl, you might think we’re talking about the herb “fennel” but she’s actually asking about phenyl which is a benzene ring minus a hydrogen atom. Phenyl doesn’t exist on its own – it’s always attached to something else. So she guessed that the ingredient is actually phenol which is a phenyl group bonded to an OH group. That’s also known as carbolic acid and it’s very dangerous to put that on your skin because it can cause chemical burns.

Ingredient list: Phenyl, Timethiconee, Cyclopentasiloxane/Dimethiconol/Dimethicone Crosspolymer, Argania Spinosa Kernet Oil, Oley Erycate, Cocos Nucifera Oil, Triticum Vulgare Germ Oil, Dicapryl Carbonate, Cyclopentasiloxane, Parfum(Fragrance).

Actually there’s a typo mistake on the ingredient list. The chemical is actually “phenyltrimethicone” and it has nothing to do with phenol.

I don’t know if the mistake is just on the website or on the product itself but it just goes to show you the importance of proof reading your work. Also, if you see an ingredient list that just doesn’t make sense for some reason – it could be that it’s just wrong.

Do silicones build up on skin?

RJ says…I’ve noticed that you’ve often touted silicones as excellent hair conditioners. However, you haven’t talked much about the impact of silicones on skin. I assume they carry similar pros and cons to hair application; the pros being excellent occlusive properties and the cons being potential buildup. Is this a correct assumption?

First a point of clarification: silicones aren’t necessarily good for hair because of their occlusive properties. Your hair is going to equilibrate to the humidity around it. It’s not like your skin where you need to to seal in the water to keep it moisturized.

On hair, conditioning is more about smoothing the surface and evening out the cuticle to reduce friction, provide a smooth feel, and increase shine. On skin, on the other hand, it is all about occlusion. Silicone, dimethicone in particular, is such a good barrier agent that it is actually approved as an over-the-counter drug active in skin protectant products. But while we’ve all heard the complaint that silicones build up on hair I’ve never heard anyone raise that concern about skin.

I think the reason for that twofold. First I’m not convinced that silicones are as resistant to wash off as people seem to believe. I’ve looked into this in the past and never really found data showing that silicones are that hard to get off of your hair. Second, skin, unlike hair, is constantly shedding its outer layer. As the dead skin cells flake off you’re also getting rid of any thing that might have stuck to the surface.

So the quick answer is, I really don’t think this is a problem.