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Does silk protein really help your hair?


Ligirl217 says: I use Rusk’s smoother shampoo and calm conditioner. I would not buy my hair products at a drug store because they are loaded with stuff that makes you feel like your hair is silkier but it actually does nothing to solve the problem with keeping your hair in good condition. I use a deep conditioner by the brand Italy which makes hair dye and is sold at my salon…this thing is god sent because my hair is AMAZING after I use it (once a week). Here’s a trick: when shopping for both shampoo and conditioner, make sure to read the ingredients and look for silk or wheat proteins…it’s the key to healthy hair!

The Right Brain Responds:

We’d love to find out exactly which “Italy” deep conditioner you’re using, we’re not very familiar with that brand. However, we are very familiar with conditioner formulations so here’s the real scoop. First of all, from a scientific standpoint, there’s nothing inherently different about drug store conditioners. It is NOT true that they use ingredients that are very different than most of the salon or department store brands. There are good and bad products in drug stores and there are good and bad products in salons. Where you buy the product doesn’t tell you ANYTHING about how good it is!

Protein power

Now let’s address your second point about looking for silk or wheat proteins because they are the key to healthy hair. Although your hair is made of protein, protein doesn’t do much when added to your hair from shampoo or conditioner. That’s because to be made soluble, proteins have to be broken up into tiny pieces (called hydrolized proteins). These little protein fragments are not very effective and forming the kind of films your hair needs to more conditioned. Therefore, it’s the other conditioning agents in the formula that are really smoothing the cuticle and protecting your hair from damage.

The Beauty Brains bottom line

There’s nothing wrong with using expensive salon brands and looking for ingredients that you like. But just remember, there’s a lot of advertising hype in this industry so be careful. The more you know the truth about your products, the better shopper you’ll be!

{ 9 comments… add one }

  • slender January 2, 2014, 11:36 am

    Thanks for the clarification. I use sensai/kanebo who claims that silk is the key ingredient in making its products effective. Actually, I have never believed this for an instant. (I assumed it is just marketing nonsense.) I just like the moisturizing effects of the liquid face creams. Yet, they have become very expensive, don’t contain any sort of sun screen and constantly try to insist that has to buy the lotion as well, which looks basically like coloured water but costs almost the same as the creams. I am starting to think I ( or my bank account) may be better off using Olay or Olaz (different spelling in Europe).

  • Rebecca June 10, 2016, 3:40 pm

    Actually too much protein can make your hair so brittle it snaps, you need a good protein and moisture balance for healthy hair and especially if you have naturally curly/wavy hair moisture is a must, I’m a hairdresser and don’t recommend a lot of salon shampoos and conditioners unless I know the ingredients and the sulphates have to be derived from coconut and I never ever recommend shop ones as i personally find them to be nasty and don’t get me started on Pantene!!!!!! but I think coconut oil would be a better deep conditioning,moisturising and smoothing treatment than most well know brands, all the different products bamboozle my brain! So many chemicals!

    • Randy Schueller June 10, 2016, 10:00 pm

      Thanks Rebecca. If you can direct us to any evidence that too much protein makes your hair brittle, we’d love to share that with our readers. From a scientific perspective we’ve never seen proof of that and so we’re understandably skeptical. Thank you!

      • Calie Nicole March 9, 2017, 11:08 pm

        Hi there! I know this is a relatively old post, but I just randomly stumbled upon it today. The commenter is correct in stating that too much protein is indeed bad for your hair. Known as a protein overdose/overload-it can cause your hair to become very dry and brittle and shed/break off. I believe this is due to an imbalance in the protein pH as well as protein vs moisture level. Strength and moisture, in terms of hair, are 2 different things. Moisture makes it soft, protein gives it strength. Many protein treatments (ApHogee 2 Step Treatment, for example) will stress the importance of making sure the hair is moisturized well afterwards, and that the protein treatment is very thoroughly rinsed. Again, that treatment as an example, literally makes your hair rock hard as it’s drying/processing.

        Coconut oil can also be damaging to people’s hair, as some of the fatty acids in it are too big to penetrate the hair follicle, causing overload and breakage as well. Overdoing it with any oils can be detremental to your hairs integrity. Going back to strength vs. moisture- for hair to be soft and healthy, water needs to penetrate the shaft/follicle. It’s especially important to keep in mind when washing your hair- if your hair is coated in oils before it’s wet, or even during washing, it doesn’t give your hair the chance to soak up/”fill” itself with those water molecules, as we all know water and oil don’t mix. If you coat your hair in any oil before washing, or if it’s got lots of product build up, you can notice how it takes your hair a bit longer than usual to get super wet.

        Lots of people out there associate oils and protein with healthy hair, focusing on strength, without taking into account that they need to use simple moisturizing products/ingredients as well. Brand and cost doesn’t matter so much as what’s on the actual ingredient label.

        You can find lots of information on what I’ve pointed out online, there’s more and more of it coming out daily, I think it would be good for more beauty-centric websites to make it clear that too much of a good thing is totally possible.

        I hope this helped give you guys some insight!!!! 🙂

        • Randy Schueller March 10, 2017, 6:10 am

          Hi Calie. Thanks for taking the time to leave a thoughtful comment! I’d love to learn where you’re getting your information on “protein overload.” I haven’t been able to find any scientific basis for this problem. In fact, we talked about why this is a myth in a previous podcast. Here’s the link: http://thebeautybrains.com/2016/06/can-hair-really-be-sensitive-to-protein-episode-139/

          • Julia Kontis April 20, 2017, 4:45 am

            There are some statements in literature mentioning some observed effects of protein over-saturation, but they lack explicit explanations.
            For example in Goddard, E. Desmond, and James V. Gruber, Principles of polymer science and technology in cosmetics and personal care. CRC Press, 1999, p. 441 (subsection: Proteins in Cosmetics) or in a article by the same author:
            “Role of protein in cosmetics.”, Secchi, G., Clinics in dermatology 26.4 (2008): 321-325.
            I quote: „Accumulation of peptides on hair surface after repeated protein applications could theoretically occur over the saturation level through the binding of new peptides to those previously attached to hair fibers. This normally brings unwanted effects (hair heaviness, stiffness and bad texture).“

            I have two explanations for the assumption, that protein hydrolyzates sometimes seem to dry out hair, or rather give the impression of dryness.
            The first explanation for the impression, that protein hydrolyzates seem to be drying is due to a swelling of the hair shaft caused by water absorption and scale lifting as a crucial consequence. By using high concentrations of humectants, the hair shaft attracts more water, hence, swells more than usual at a given humidity. If the hair shaft swells too much, cuticle scale lifting occurs.
            It is to be assumed, that protein hydrolyzates behave the same way, since they are humectants as well and therefore attract water. Especially those with small moleular weight have hydrophilic properties: Free amino acids and small peptides of a few amino acids.
            If the hair shaft is swollen and cuticles are raised, inter-fiber friction, therefore combing forces increase, whereas the tensile strength and force to break decrease slightly due to the softening effect of water – I often recognize, that consumers sometimes wrongly confound or equate tensile strength with elasticity of hair fibers, although hair fibers with higher moisture contents actually have lower tensile strength values.

            The statement, that dry feeling hair actually comprises an higher moisture content, sounds contradictory, but it has been shown that the haptic perception of moistured hair obviously does not depend on the real water content of hair. The perception depend mainly on a smooth (good conditioned) hair surface, ergo flat, structurally intact cuticle scales. Thus, an uneven surface caused by scale lifting lead to the perception of dryness.
            Therefore the consumer perception of moistured hair is not congruent with the real water content of hair. This discrepancy has been shown by Davis and Stofel in consumer panel studies:
            MG Davis and S Stofel, Consumer perception versus single and bulk fiber technical measurements, Proc 16th International Hair Science Symposium, Weimer, Germany (2009). There is an article on cosmetics and toiletries (Water Content and Moisturization), which summarize their findings. These findings are also mentioned in Clarence R. Robbins, Chemical and Physical Behavior of Human Hair, 5 Edt., Springer, 2012, p.643 f.

            These interrelationships explain two symptoms for „protein overload“, which are mentioned above: hair heaviness and bad texture. More breakage might be observed, because of higher combing friction and because hair is weakend due to the softening effect of water. Unfortunately, I can not find any microscopic studies to confirm the assumption that an overdose of protein uptake can cause cuticle scale rising. Moreover, this approach does not explain the described stiffening of hair fibers.

            My second approach to explain the perception of dry hair after „protein overload“ is totally different but it explains the stiffening of hair. Stiffness has been stated as a symptom for protein over-saturation by Secchi et al. and I often observe this phenomenom in my hair community.
            It is important to mention that in general stiffening of hair is associated with drying action, too. Dry hair fibers, for example in very low humidities, become stiffer.
            But in which way proteins may cause a stiffening of hair fibers?

            The cortex cells of hair consists of keratin filaments and an amorphous matrix of globular proteins. Water can interpenetrate the latter and thereby effects the physical properties of the whole fiber.
            The strength of hair (tensile strength) is not only caused by covalent bonds – coulombic forces and hydrogen bonds are also envolved. Hydrogen bonds can be formed between two matrix protein chain residues or between protein residues and interpenetrated water molecules. Because hydrogen bonds between protein and water molecules are weaker than those between two protein chains, water decreases the tensile strength of hair fibers (the actual molecular mechanism for the softening effect of water). Therefore water is deemed to be a plasticizer for hair. This is why wet hair is weaker than dry hair in relation to its tensile strength.
            Even at moderate and low humidities water molecules are attached to the protein chains in that way giving the fiber its mechanical properties.

            Possibly, amino acids and very small peptides are able to occupy the space between globular matrix proteins and able to replace water molecule and even to prevent water molecules from replenish the narrow spaces between the matrix protein chains. As a result they form stronger hydrogen bonds between the surrounding matrix protein chains and because these new bonds are stronger than water-protein bonds, an higher force to rearrange and unfold the protein structure during stretching and deformation is required. This molceular mechanism apparently refers to the promised strengthening effect of protein hydrolyzates (aside from possible disulfide interchange reactions). But these molecular interactions also cause a stiffening effect, which is not as easy to reverse by rewetting, because moisture uptake may be precluded by steric factors. Thus, moisture uptake of the protein matrix in fact may decrease in relation to the usual uptake. If small protein fragments and amino acids interact with the protein matrix in that way, the effect could be considered as a dehydrating effect.

            The following excerpt is another hint in literature for these molecular interactions:
            I quote: „The nature of the wet matrix has been further elucidated by the results of a number of workers who have studied the changes of water sorption and mechanical properties of different a-keratin fibers with change in the proteins content of the matrix. The results of this work can be summarized as follows (7,8): (a) Increase of matrix protein reduces the water sorption of the matrix. (b) Concomitant with the reduction of water content of the matrix is an increase in the mechanical stiffness of the matrix. […] With the distance between microfibrils fixed for the fiber in the wet state an increase of high sulfur protein (or any other material) into the matrix space between the microfibrils reduces the space available for water. Simultaneously this would increase the effective mechanical stiffness of the matrix, a matrix that must be considered to be matrix protein plus water.“
            Johnson, Dale H., ed. Hair and hair care. CRC Press, 1997, p. 15f.

            Alternatively, this statement can be found in “Feughelman M., Mechanical properties and structure of alpha-keratin fibres: wool, human hair, and related fibres. 1997, Sydney, Australia: University of New South Wales Press”, p. 26.
            There are some other publications dealing with impacts of other organic molecules on hair properties with similar described effects:

            Orfanos, Constantin E., W. Montagna, and G. Stüttgen. Hair Research. Berlin Heidelberg New York: Springer, 1981.
            Chapter: The Binding of Small Molecules and Polymers to Keratin and Their Effects on the Physicochemical and Surface Properties of Hair Fibers, M. M. Breuer Gillette Research Institute, Rockville, Maryland, USA; subsection: The Binding of Organic Materials to Hair and The Effect of Absorbed Molecules on the Mechanical Properties of Hair.

            This section describes some effects of phenols in hair. Phenols are also expected to compete with water for the binding sites. Their large aromatic rings attached to the protein chains instead of mobile water molecule reduce the ability of two opposite protein chains to move relativ to each other. As a consequence the hair fiber becomes stiffer.
            It can be assumed, that this concept of molecular interaction is transferable to amino acids or very small peptides (dipeptides). Perhaps, the described effects on fiber properties might be typical for certain amino acids, maybe aromatic amino acids.

            Additionally, I have found a publication investigating the effects of organic acids in hair.
            Itou, Takashi, and Masayoshi Nojiri. “Study of the interaction between hair protein and organic acid that improves hair-set durability by near-infrared.” J. Cosmet. Sci 57 (2006): 139-151. Figure 8 is a very expressive drawing. Citric acid or organic acids in general can displace water molecules between the protein chains in an analogous manner.
            These molecular interactions may explain some consumer perceptions regarding frequently used products or rinses with organic acids: A stiffening of hair and as a consequence the observation that frequently or intensive treatments with citric acid result in stiff (dry) hair. The drying effect of citric acid is also mentioned in the article of on cosmetics and toiletries (Water Content and Moisturization).

            The following publication might be interesting, in so far it compares hydrolyzed wheat proteins and silk amino acids.
            Gomez-Garcia, M. “Effects of some oils, emulsions, and other aqueous systems on the mechanical properties of hair at small deformations.” Journal-society of cosmetic chemists 44 (1993): 69-69.

            Additionally, a stiffening of hair fibers can be provoked by other mechanisms, for example crosslinking of protein side chains caused by tanning processes in natural hair dyes (tannin molecules would form a large number of hydrogen bonds; naphthoquinones are expected to bind even covalent via michael addition), crosslinking agents like formaldehyd, or by natural radiation etc. All these processes are associated with dehydrating effects.
            Furthermore, there are several in situ condensed (co-)polymer networks. They promise or perhaps in fact provide more strength by building up a stabilizing polymer networks within the hair fiber, but these networks stiffen the fibers. For this product concept, mainly reactive silylated proteins or reactive monomers like aminopropyl triethoxysilane (APTES) are used in some hair cosmetics nowadays. It is assumed that the oligomers undergo a condensation process. The process of the latter can be found under the heading „sol-gel process“:
            Hallegot, P., et al. “Discovery of a sol–gel reinforcing the strength of hair structure: mechanisms of action and macroscopic effects on the hair.” Journal of Sol-Gel Science and Technology 79.2 (2016): 359-364.
            Products containing these reactive silicone precursors are often facing critism, because they are said to be drying out. It is probable that this perception is likewise caused by the stiffening effect due to rigid polymer networks formed in situ.

            I bring this up, because Aphogee mentioned here includes several compounds which may induce stiffening of the hair via some of my discussed mechanisms: a formaldehyde-releasing agent – formaldehyde crosslinks some protein chains; citric acid, which replace water molecules between the matrix protein chains; and silylated proteins, which may form a rigid protein/ siloxane copolymer network within the hair. I guess the collagen hydrolysate is used for film forming purposes.

            In summary, it can be said that strengthening effects are normaly accompanied by stiffening of hair fibers and this stiffening is accociated with dry hair, whether it is caused by reduction of water content of the protein matrix or whether it is caused by crosslinking of hair proteins or by interpenetrating (Co-)polymers.

          • Randy Schueller April 20, 2017, 7:22 am

            Excellent review of the literature! I learned a lot. Thanks for taking the time to put this together.

          • Julia Kontis April 29, 2017, 7:30 am

            Thanks!
            Well, this is just an attempted explanation for some observations. I tried to explain the effects on hair based on evidences from the literature.
            What do you think? Is it worth to pursue this approach? After all, there is no direct link to protein hydrolyzates and the supposed effects on the matrix proteins.

          • Randy Schueller April 29, 2017, 8:19 am

            I’d love to see someone conduct experiments to validate your hypotheses. The first one (about the proteins attracting so much moisture to the hair shaft that it swells) is very interesting but I’m skeptical that the effect would be that pronounced.

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