Thursday, November 19, 2009

Gamma linolenic acid

Gamma linolenic acid (C18:3) is another essential fatty acid, one our bodies can't produce. It has three double bonds, meaning it is a fatty acid that is going to oxidize quickly, so we need to combine it with some good anti-oxidants or use it quickly in our lotions. It is found in small quantities in the ceramides in our skin.

GLA can have anti-inflammatory effects on our body and skin. It helps with the conversion of linoleic acid into arachidonic acid (if you want to know more about this, check out the Wikipedia entry) and helps with the anti-inflammatory and immune systems in our bodies. In animal studies, GLA in the form of borage oil was effective in reversing epidermal hyperproliferation (skin cells proliferating too quickly) and increasing ceramide synthesis in guinea pigs (although they ate it, rather than slathering on a decadent lotion!) Evening primrose was not as effective. Ironically, in human studies, ingesting evening primrose oil shows good signs of treating eczema and skin irritation, although similar studies of borage with eczema didn't show the same results.

Applied to our skin, GLA can be a great anti-inflammatory, improving skin's protective qualities and helping repair the skin barrier faster than linoleic acid. Like the oils containing linoleic acid, GLA will help with itchy dry skin, act as a moisture retainer, and helps with acne prone skin. And GLA containing oils are absorbed quickly into the skin, increasing skin's flexibility and suppleness.

Evening primrose oil specifically has been found to reduce transepidermal water loss (TEWL) and increase stratum corneum hydration in normal skin, but it doesn't seem to help as much as borage oil with atopic dermatitis (chronic inflammation of the skin that causes an itchy, swollen, red rash).

GLA is found mostly in what I have called exotic oils - oils we don't tend to use in great quantities like we do the carrier oils mainly because they are freakin' expensive! Evening primrose, borage, rosehip, and blackcurrant oils are filled have good levels of GLA from 15 to 23%.

How much GLA should we use in our products? Unfortunately, this information is sketchy at best with no consensus. We have suggestions from manufacturers to use up to 10% evening primrose and 10% borage oil, but the studies just aren't there to suggest these amounts are correct.

Join me tomorrow for a few ideas on how to use GLA in your lotion recipes.

3 comments:

Gold prices said...

Well this sounds interesting and it is best to follow natural care. Natural or herbal products are always better in comparison to chemical based products.

Susan Barclay-Nichols said...

Everything is composed of chemicals - water, air, my dog, calendula oil, beeswax - so, by definition, everything is a chemical based product. Natural doesn't necessarily mean good, and "chemical" or synthetic doesn't necessarily mean bad. Botulism, poison ivy, and mosquitoes are natural, but they can cause severe reactions and death in most (if not all) people. (Although having said that, a lot of women are quite grateful for small doses of Botox, so it just goes to show you it's all about the dosage!)

My philosophy on ingredients in my products is this - if I like it, I use it. I do my research and make sure I know as much as I can about the ingredient. If it seems like a good ingredient, it goes into my product. Then I consider the skin feel, the cost, possible substitutions for it, and so on. I may consider the origin of the ingredient, but for the most part, my main concerns are the quality, skin feel, and what the ingredient brings to the party!

If you want to stick with all natural or herbal ingredients, have fun! Know your ingredients well and ensure you preserve them properly.

Please don't use the word "chemical" to imply a product is bad. Every product contains chemicals - the question is whether those chemicals are beneficial for us or not.

Thus endeth the rant...

Jodi said...

Hi Susan,

You listed Rosehip oil as one of the oils that has GLA in it. The research I've read says that rosehip oil contains alpha-linolenic oil - not gamma-linolenic oil. As you know, they are both "18:3" but the ALA is (n-3) and the GLA is (n-6).

The only other oil I have found, so far, that has a significant amount of GLA (other than Borage, Evening Primrose & Black Currant oils) is Hemp Seed Oil.

Thank you for your obsession with cosmetic chemistry! I like to think of it as skin health chemistry!