Essential fatty acids in the liver and adipose tissue of genetically obese mice: effect of supplemental linoleic and gamma-linolenic acids.

Genetically obese mice (ob/ob) and their lean litter-mates were given diets iso-energetically supplemented with sucrose, hydrogenated coconut oil, safflower oil or evening primrose (Oenothera biennis) oil. Weight gain over 15 weeks was significantly greater in the evening primrose oil-supplemented obese mice than in the other groups. In all the groups of obese mice, liver total phospholipids contained proportionally less linoleic acid and more dihomo-gamma-linolenic acid and arachidonic acid than did the lean controls. As a percentage of total fatty acids, n-3 essential fatty acids (EFA) in liver and adipose tissue lipids were significantly lower in the obese mice than in the lean controls. Supplementation with EFA-rich oils (safflower and evening primrose oil) increased the proportional composition of n-6 EFA and decreased the n-3 EFA more in the liver total phospholipids of the lean than the obese mice.