The invention relates to an extract of flax (Linum) originating from the hydrolysis of flax proteins and to a cosmetic composition comprising same. The invention also relates to a synergic cosmetic composition comprising a flax extract as a first active principle and coenzyme Q10 as a second active principle. The invention further relates to the use of a cosmetic composition intended to protect the skin and appendages from external aggression and to delay the visible signs of cutaneous aging.EXTRAIT DE LI