The active molecules that make up avocado oil.

The avocado tree is a member of the Lauraceae family, originating from Central America. It produces a fruit rich in fatty matter, boasting numerous nutritional benefits, but also cosmetic ones. Obtained by first cold pressing of the fruit kernels, it presents itself as a thick oily liquid ranging from yellow to brown in colour, with a characteristic mild scent and a rather rich feel. When the temperature drops (< 20°C), the oil solidifies and becomes almost solid.

Avocado vegetable oil has been used since the Middle Ages, and was notably employed by the Aztec populations. They used it in skin application to protect themselves from dryness, but also in hair application, for its nourishing and protective virtues. The various properties of avocado vegetable oil come from its biochemical composition, which we invite you to discover.

Avocado oil contains monounsaturated fatty acids such as oleic acid, at approximately 55%. Belonging to the omega-9 family, it can be synthesised by the body from other fatty acids. Oleic acid is naturally present in the hydrolipidic film of the skin. This is found on the surface of the epidermis and acts as a shield to keep the skin hydrated and protected from external aggressions (wind, cold, pollution...).

This fatty acid has beneficial properties for skin protection, as it helps to strengthen the hydrolipidic film. We also find palmitoleic acid in avocado vegetable oil, present at approximately 10%. This molecule is an omega-7, like oleic acid, it is a component of sebum.

Avocado vegetable oil is composed of approximately 10% linoleic acid. This essential unsaturated fatty acid belongs to the omega-6 family and cannot be synthesised by the body. From an epidermal perspective, linoleic acid indirectly contributes to the formation of the skin barrier by triggering a cascade of biochemical reactions that ultimately lead to the stimulation of cellular renewal.

It also plays a role in the synthesis process of ceramides. Indeed, ceramides result from an amidation reaction between a sphingoid base and a fatty acid. Those carrying a linoleic acid are referred to as acylceramides. Ceramides are lipids naturally present in the skin and ensure good cohesion between the cells of the stratum corneum. They play an important role in protecting the skin from external aggressions and dehydration.

A deficiency in linoleic acid leads to the weakening of the epidermal barrier and an increase in the transepidermal water loss (TEWL). As a result, the skin becomes drier, rougher and more prone to irritation. The loss of skin hydration also promotes the appearance of wrinkles and fine lines, making them more visible.

Avocado vegetable oil also contains saturated fatty acids such as palmitic acid, at approximately 20%. These active ingredients have a film-forming effect on the skin and contribute to the maintenance of the hydrolipidic film. Moreover, these compounds have a structure similar to that of the molecules structuring the horny layer, allowing them to integrate into it and facilitate its restoration. Skincare products containing avocado vegetable oil are therefore recommended for dry or atopic skin. They also help the skin to restore its lipid composition after prolonged exposure to the sun or pollution.

Tocopherols (vitamin E) are natural antioxidants. They protect skin cells from free radicals, reactive oxygen species responsible for premature skin ageing. In the case of avocado oil, tocopherols work by transforming hydrogen peroxide (H₂O₂), which causes damage to DNA and proteins, into water (H₂O). These active ingredients are therefore excellent allies for preventing the appearance of wrinkles, fine lines and other signs of skin sagging. Furthermore, tocopherols help to limit the oxidation and rancidity of avocado oil, providing it with a better stability over time.

Phytosterols are also found in avocado vegetable oil. More specifically, these are sitosterols at 90% and campesterols at 10%. These compounds contribute to maintaining the skin's barrier function and have soothing properties. They also have anti-inflammatory activity and regulate certain inflammation processes. However, the mechanism by which these molecules act has not yet been fully elucidated and further research is still required. Avocado oil can thus be used to relieve itching and certain redness.

Avocado oil is also enriched with alpha- and beta-carotenes, carotenoids. These compounds are potent antioxidants, capable of trapping free radicals in cells. They thus help to slow down skin ageing. In addition, beta-carotene is one of the main precursors of vitamin A, also known as retinol, meaning it has the ability to transform into vitamin A, according to the body's needs. Vitamin A contributes notably to the maintenance of healthy skin, mucous membranes and hair, as well as to the normal functioning of the immune system. Retinol is also known for its beneficial properties on skin ageing as it is capable of stimulating the synthesis of collagen and elastin.

In order to restore the shine and softness of dry and damaged hair, Typology has developed a repairing hair mask. This treatment is enriched with biomimetic ceramides (INCI name: Behenyl/Stearyl Aminopropanediol Esters) and avocado oil (INCI name: Persea Gratissima (avocado) Oil) which deeply repair and nourish the hair fibre to soften the hair and prevent the appearance of split ends. Indeed, the richness of avocado oil in fatty acids allows it to restore the cuticle, the protective layer of the hair fibre, and to tighten its scales. Moreover, the hair ends are less likely to get damaged quickly thanks to its antioxidants.

This mask is to be used 1 to 2 times per week. Its creamy texture instantly coats the hair fibre and softens the hair without weighing it down. It should be applied to washed and towel-dried hair from mid-lengths to ends. Allow it to work for 5 to 10 minutes before rinsing thoroughly.

• HAUSER M. & al. In vivo investigations on the penetration of various oils and their influence on the skin barrier. Skin Research and Technology (2012).

• ORTIZ-VIEDMA J. & al. Avocado oil: characteristics, properties, and applications. Molecules (2019).

• HEREDIA J. B. & al. Fatty acid profile, total carotenoids, and free radical-scavenging from the lipophilic fractions of 12 native mexican avocado accessions. Plant Foods for Human Nutrition (2019).