Used since time immemorial, carrier oils are true natural treasures essential to any wellness and cosmetic routine. Equally beneficial and sometimes even complementary according to their geographical origin or biological family, each of these resources has very specific characteristics that make them unique.
Such differences are mainly explained by the composition of carrier oils, very rich in lipids (up to 99%) which correspond to the fat content of living beings (from the ancient Greek "lipos", fat). In particular, lipids themselves consist of fatty acids that form the base of these oils and determine their texture, their properties and consequently their benefits on the human body.
Covered with a hydrolipidic film, a real protective shield made of sebum (full of lipids itself), sweat and water, the skin perfectly matches with these natural oils that help moisturize, nourish, preserve and beautify it. Understanding fatty acids is therefore necessary to choose the most fitting carrier oils according to one's skin type and needs.
Those lipid molecules of different kinds are more generally classified into three major groups according to the number of carbon atoms and double bonds that constitute them and determine both their shape (short, long or very long chain) and their properties:
- Saturated: so called because of their carbon atoms totally saturated in hydrogen, these active ingredients mainly contribute to maintaining the skin's barrier function. With a rich and solid texture at room temperature, slowly absorbed, they are for example found in the Coconut carrier oil, which is highly protective, thick and semi-solid.
- Monounsaturated: these molecules whose carbon atoms have a double bond (C=C) correspond to the well-known omega-9s, with a liquid texture at room temperature. Important for the body, these fatty acids are mostly restorative and promote the skin's hydration, suppleness and elasticity. The oils of Camellia Seed (85%) or Hazelnut (70%) are especially full of them.
- Polyunsaturated: Essential for human beings who cannot synthesize them and must therefore draw them from their environment and their diet, these fatty acids whose carbon chain has several double bonds involve the omega-3s, nourishing and soothing, and the omega-6s, protective, nourishing and regenerating. The texture of these active ingredients at room temperature is also liquid. Specifically, the Hemp carrier oil is highly concentrated in omega-3 (20%) and the Evening Primrose one in omega-6s (+80%).
In particular, four main fatty acids are frequently found in the composition of carrier oils:
- The linoleic acid, grouped as polyunsaturated: this omega-6 mainly contributes to maintaining the skin's barrier function as mentioned above. Oils rich in linoleic acid, including Prickly Pear (62%), Blackberry Seed (65%) and Grape Seed (70%), are renowned for their thin texture and for being absorbed as easily as deeply by the epidermis.
- The gamma-linolenic acid, grouped as polyunsaturated: this other omega-6 is characterized by its anti-inflammatory, soothing, healing and regenerating virtues. In supplement, it allows to maintain the barrier function as well as the hydration of the skin. Fluid and liquid without leaving any oily film, the carrier oils rich in gamma-linoleic acid, such as those of Borage (20%) and Blackcurrant (15%), are also easily and deeply absorbed.
- The alpha-linoleic acid, grouped as polyunsaturated: this omega-3 has powerful soothing and anti-inflammatory properties, thus relieving skin irritations or redness. Nourishing and very thin, carrier oils with a high omega-3 composition, such as Sea Buckthorn (30%) and Camelina (30%), penetrate the epidermis very easily.
- The oleic acid, grouped as monounsaturated: By helping to reinforce the hydrolipidic layer, this omega-9 promotes the skin's elasticity, suppleness and moisturization. It is also well-known for its soothing, anti-inflammatory and regenerating virtues. Key carrier oils rich in omega-9 include Avocado (60%), Sweet Almond (70%) and Olive (60%), all of which are semi-fluid in texture and easily absorbed.
Depending on their lipid molecule composition, carrier oils will vary in texture and benefits. Generally speaking, the richer a carrier oil is in polyunsaturated fatty acids, the more penetrating it is. Those with a high and balanced content of omegas-3 and 6 are particularly anti-inflammatory and soothing, suitable for sensitive skins. The more monounsaturated fatty acids an oil contains, the more softening and soothing it is.
In light of these elements and depending on its fatty acid content, each carrier oil will be more or less adapted to each skin type. More specifically:
- Dry skins: Prefer oils very rich in monounsaturated fatty acids (omega-9), intensely moisturizing, protective, softening and soothing in order to restore the hydrolipidic film and prevent the skin from drying out.
Recommended: The Avocado, Coconut, Macadamia or Sweet Almond oils
- Normal skins: Select protective and softening oils (omegas-6 and 9) to preserve and maintain the skin in good condition.
Recommended: The Apricot Seed, Jojoba or Macadamia oils
- Oily skins: Contrary to what is usually thought, such skins need to be moisturized and nourished just as much. Preferably choose dry oils that are rich and balanced in omegas-6 and 9 to hydrate, regenerate and balance the skin by regulating excess sebum.
Recommended: The Black Cumin, Grape Seed, Hazelnut, Jojoba or Raspberry Seed oils
- Mature skins: Focus on oils with softening, firming, moisturizing and regenerating virtues in order to avoid skin slackening.
Recommended: The Argan, Camellia Seed, Rosehip or Sea Buckthorn oils
To go further, we recommend the book written by PARKER Susan, Power of the Seed, your guide to oils for health & beauty, Process Self-Reliance Series, 2014.