Concentration and ratio of essential fatty acids influences the inflammatory response in lipopolysaccharide challenged mice.

The goal of this study was to evaluate the role of both the % of dietary, 18-carbon PUFA (2.5%, 5% and 10%) and the n-6:n-3 ratio (1:1, 10:1 and 20:1) on the acute inflammatory response. Mice were fed diets for 8 weeks and injected intraperitoneally with LPS to induce acute inflammation. After 24h mice were sacrificed and plasma cytokines measured. Diets significantly affected the erythrocyte PUFA composition and the effect of PUFA ratio was more prominent than of PUFA concentration. The % dietary PUFA affected feed efficiency (p<0.05) and there was a PUFA×ratio interaction with body fat (p<0.01). In mice fed high %kcal from PUFA, those given a low n-6:n-3 ratio had more body fat than those fed a high ratio. Of the twelve cytokines measured, eleven were significantly affected by the % PUFA (p<0.05), whereas five were affected by the ratio (p<0.05). For seven cytokines, there was a significant PUFA×ratio interaction according to a two way ANOVA (p<0.05). These data indicate that dietary polyunsaturated fatty acids can affect LPS induced-inflammation.