pure vegetable/triglycerides oil function as humectant because it has high % of glycerin?

Abdullah

"Glycerol can be found in the triglyceride structure of oils/fats, and the content ranges from approximately 9 to 13.5%."

does it mean applying pure vegetable oil to skin function as a product with 13% glycerin in term of humectancy because it has this much glycerin?

Pharma

No, it's chemically bound glycerol and does not act like free glycerol. Neither do the fatty acids which make up the other part of triglycerides.

MattTheChemist

@Pharma thank you for saying this!

I see far too many people claiming benefits of plant lipids due to the FA content, but we know that very few FA's are free within the oil, and most are bound in triglyceride form.

For instance, there are data showing the benefit of Linoleic Acid for the skin barrier so the assumption is that an oil high in LA content provides the same benefit...some even saying that microbial lipase enzymes will cleave the ester bond and free the fatty acids when the oil is applied topically.

I cannot find ANY evidence of this in the literature. What are your thoughts here?

jemolian

Lab muffin as a blog post on oils & free fatty acids, not sure if it would be useful for some references that you might fine interesting. https://labmuffin.com/video-skincare-oils-free-fatty-acids-science/

Abdullah

Pharma said:

No, it's chemically bound glycerol and does not act like free glycerol. Neither do the fatty acids which make up the other part of triglycerides.

@Pharma that is interesting.

So in theory, applying which one is better on skin? A vegetable oil like coconut oil or a blend of free fatty acids at same ratio as coconut oil?

Abdullah

@MattTheChemist they free the oleic acid and cause dandruff. Not sure about others. 

Abdullah

@jemolian thanks a lot 

in this link says "lauric acid is strongly antibacterial, and works better than benzoyl peroxide against Propionibacterium acnes bacteria." is this true?

MattTheChemist

@Abdullah I believe that happens in-vivo with the triglycerides in the follicle sebum, but the question is if topically applied triglycerides (plant oils) get broken down into the FFA's when applied. 

@jemolian great article by Michelle! She seems to agree that there is little evidence to prove this. 

Pharma

It's not just microbial lipases which break down triglycerides. Living skin cells (all living cells for that matter) will do the same. Unlike microbes, skin do it in a very ordered and highly regulated way whilst microbes secrete enzymes in order to digest their environment for easier take up.

Providing omega-3 and other polyunsaturated fatty acids can have a benefit. However, good scientific evidence regarding topical supplementation is scarce and often contradictory (even oral supplementation isn't always evident).

Restoring skin barrier is a physical function as much as it's a physiological one and both are a result of many different factors. There is not one answer and the instant you apply a mixture of ingredients, things can change dramatically compared to published/scientific studies.

Abdullah

@Pharma thanks a lot

MattTheChemist

@Pharma thank you