Comparison of the clinical and biochemical effect of increased alpha-linolenic acid in a safflower oil intravenous fat emulsion.

We report the results of a randomized comparison of two intravenous safflower oil (fat) emulsions in neonates who required total parenteral nutrition. The fat emulsions differed only in their content of alpha-linolenic acid: in one emulsion the alpha-linolenic acid content of the oil was 0.1% of fatty acids, while in the other emulsion the alpha-linolenic acid content of the oil was 3.0 +/- 1.5% (SD) of fatty acids. Group 1 and 2 patients received the "low" and "high" alpha-linolenic acid emulsions, respectively. Ten patients were studied in each group. The mean daily fat dosage was 1.70 g/kg in patients of Group 1 and 1.56 g/kg in those of Group 2. No significant difference in the clinical effects of either fat emulsion could be detected between the two study groups. Both emulsions prevented or corrected biochemical signs of essential fatty acid deficiency. The major statistically significant difference between study groups was in the level of alpha-linolenic acid and its metabolite, eicosapentaenoic acid. After 2 weeks of fat therapy, these fatty acids were increased in the high alpha-linolenic acid group; however, another metabolite of linolenic acid, docosahexaenoic acid, decreased during intravenous fat therapy in both study groups. Both study groups had significantly decreased arachidonic acid levels and increased linoleic to arachidonic acid ratios.