Long-chain unsaturated oxygenated compounds and their use in the therapeutical, cosmetic and nutraceutical field. Use of compounds of formula R—X wherein X is a primary alcoholic functional group —CH20H, a carboxylic functional group —COON or a C1-C4 alkyl ester group, and of mono-, di- and tri-glycerides of acid compounds R—COON and of pharmaceutically acceptable salts of those acids, wherein R is a hydrocarbon chain having from 19 to 35 carbon atoms, which is saturated or unsaturated, including from one to five ethylenic or acetylenic unsaturations, linear or branched, including from one to five methyl branches, and optionally substituted by from one to three hydroxyl groups, for the preparation of pharmaceutical or nutraceutical compositions useful for the treatment and prevention of pathologies related to a high concentration of cholesterol and lipids, pathologies associated with an increased ability of the blood platelets to aggregate and with a reduced concentration of oxygen, in the treatment of ageing processes, for the preparation of compositions of nutritional integrators aimed at weight loss and cosmetic compositions useful in the treatment and prevention of skin damage caused by free radicals.