The Role of Linoleic Acid in Skin and Hair Health: A Review.

Lipids are intimately associated with skin condition. This review aims to discuss the function of linoleic acid (LA, 18:2, ω-6), an essential fatty acid, in skin health and hair growth. In skin, LA can be metabolized into ω-6 unsaturated fatty acid, oxidized derivatives and incorporated into complex lipid molecules, including ω-hydroxy-ceramides. Previous research has revealed that skin diseases including acne, atopic dermatitis and psoriasis are associated with disordered LA metabolism. Studies based on animal or skin cell models suggest that LA or LA-rich vegetable oils, topically applied, exhibit diverse biological activities, including the repair of the skin barrier, the promotion of wound healing, skin whitening, photoprotection, anti-inflammatory effects and the stimulation of hair growth. Moreover, the underlying mechanisms of LA's beneficial effects on skin are summarized. Further research on the correlation of LA metabolism and skin disorders, a deeper exploration of the mechanisms underlying the function of LA in skin management and more investigations of its clinical application are required to enhance the understanding and utilization of LA in cosmetics and pharmaceuticals.