Scand says…Could you please explain the benefits and structure of using real silk by products in hair and skin care? ….and what might a substitute be?
The Left Brain responds:
If popularity is any indication of efficacy , then silk must really kick ass because there are 42 different silk-based ingredients that are used in well over 1000 different beauty products. (1) If only it worked like a popularity contest.
Silk on hair
Silk protein is widely used in hair care formulations as a supplemental conditioning agent. If it’s properly derivatized (i.e., chemically modified so it sticks to hair) I’ve seen evidence that it can help repair damage. Some reference to protecting hair from exposure to alkaline processing such as you’d encounter during hair coloring or relaxing. Presumably it works because of it’s ability to form a protective film on hair. There’s plenty of research by the raw material manufacturers that silk has conditioning benefits when delivered from the right vehicle, but it’s impossible to tell which finished goods manufacturers are using the silk at the required levels to deliver that benefit.
Sadly, in most hair products, silk protein in all it’s various forms is only used at token amounts to provide a label claim. The rest of the ingredients in the formula are much more impactful in terms of providing conditioning benefits.
Silk on skin
Since skin, unlike hair, is a living organ, I’m always hopeful that certain ingredients may be able to provide more of a beneficial effect. In the case of silk, I was able to find one reference that indicates a specific type of silk (Sericin from the middle silk gland of the Bombyx mori silkworm) has antioxidant properties that are beneficial to skin. It can also inhibit lipid per oxidation and is able to reduce UVB-induced symptoms in both short and long term treatments. Interestingly it can also chelate with copper.
Once again, however, the challenge is to know which products contain the right kind of silk at efficacious levels. That’s difficult, if not impossible, to ascertain without detailed information from the manufacturer. Looking at the list of ingredients can be directionally helpful but there’s not way to tell for sure how much of a given ingredient is present. If the company is using patented technology, there may be a patent disclosure which reveals how much silky goodness the product contains.
The Beauty Brains bottom line
Despite its popularity, for the most part silk is used as a “feel good” ingredient in cosmetic products. There is some research that it can protect skin from UV damage which makes me hopeful that someone will market an efficacious silk-based product.
2. S Zhaorigetu, Inhibitory effects of silk protein, sericin on UVB-induced acute damage and tumor promotion by reducing oxidative stress in the skin of hairless mouse, J Photochem and Photobiology Biol 71(1–3) 11–17 (2003) (via Cosmetics & Toiletries)
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