Seed Oil Fatty Acids in Skincare
Oils extracted from plant seeds have been used since ancient times for a variety of purposes, including cosmetic applications . Seed oils are therapeutic because of their high fatty acid content, which accounts for the “oily” or “waxy” nature of the extracts.
Fatty acids help restore natural oils in the skin . The moisturizing, softening, and anti-inflammatory properties of fatty acids are important for maintaining the stratum corneum, the outermost layer of the skin that protects it from the environment . People with fatty acid deficiencies often have scaly, itchy skin, hair loss, poor wound healing, loss of moisture, and tend to get more skin infections [6, 11].
Fatty acids are divided into two categories: saturated and unsaturated. Saturated fatty acids have no double bonds in their chemical structure, while unsaturated have at least one . There are two types of essential fatty acids [EFAs], omega 6 and omega 3, with omega 6 being more prevalent in the body . Essential fatty acids are considered “essential” because our bodies can’t make them on their own—they need to be supplemented . Both types of EFAs are polyunsaturated fatty acids, meaning they have more than one double bond in their structures. The two types of EFAs can have various functions.
One of the most important and widely supplemented EFA is linoleic acid, an omega 6 fatty acid . Linoleic acid is the most abundant fatty acid in the skin . This fatty acid is a structural precursor for cermaides that compose the stratum corneum . Supplementation of this fatty acid moisturizes the skin, heals sunburn, and treats acne . Decreased amounts of linoleic acid are found in the sebum [oil] of people with severe acne .
Α-linoleic acid, an omega 3 fatty acid, modulates the immune response of the skin . This fatty acid has effects on acne, psoriasis, eczema, and skin cancer . Another important fatty acid is oleic acid, an omega-9 fatty acid. Oleic acid is not an essential fatty acid because it can be synthesized by the body, but it is a fatty acid in many seed oils and has therapeutic effects. Oleic acid has been shown to increase the absorption of drugs such as anti-inflammatory NSAIDs by enhancing skin permeability . This fatty acid also has anti-oxidant activity . Another important fatty acid called punicic acid, an omega-5 fatty acid structurally similar to α-linoleic acid, has anti-inflammatory and anti-oxidant effects [2, 8].
Fatty acids have a variety of therapeutic effects. High amounts of oleic and linoleic fatty acids have been shown to aid wound healing and reduce scar appearance in a clinical study . They have also been shown to reduce inflammation and increase collagen formation when applied to the skin of rats . In-vitro
[outside the body] experiments with both fatty acids show they promote migration of fibroblasts [cells that make collagen], a step important to increasing the elasticity and wound healing capabilities of the skin . Linoleic acid and γ-linoleic acid [a product of linoleic acid breakdown] have been shown to improve eczema in clinical studies [5, 6]. Topical application of high amounts of linoleic fatty acids restored skin barrier function in mice after only one application . Additionally, linoleic acid was shown to have anti-fungal properties when applied to the skin of mice .
Fatty acids also have permeation enhancing affects. Of the unsaturated fatty acids, Oleic acid is reported to be an effective percutaneous absorption enhancer, while amongst the saturated fatty acids, palmitic acid had the most potent skin permeation enhancing effect. Skin permeation enhancement effects have also been recorded for linoleic, lauric, myristic and stearic acids. 
Key Benefits of Seed Oil Fatty Acids on Skin Care:
- Moisturizing and hydration [1, 3, 6, 10, 11]
- Restore barrier function [1, 3, 7]
- Anti-inflammatory [1, 2, 4, 5, 7, 8]
- Wound healing support [1, 4, 6, 7]
- Anti-acne [6, 7, 10]
- Anti-oxidant [2, 4, 8, 10]
- Increase skin elasticity [3, 4]
- Stimulate collagen production 
- Sun damage repair 
- Anti-fungal 
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 I.L.P Melo, E.B.T Carvalho, and J. Mancini-Filho, “Pomegranate Seed Oil [Punica Granatum L.]: A Source of Punicic Acid [Conjugated α-Linolenic Acid],” J Hum Nutr Food Sci
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