FORMULA ALPHA-LINOLENIC (18/3(N-3)) AND LINOLEIC (18/2(N-6)) ACID INFLUENCE NEONATAL PIGLET LIVER AND BRAIN SATURATED FATTY-ACIDS, AS WELL AS DOCOSAHEXAENOIC ACID (22/6(N-3))

Saturated fatty acids can be synthesized de novo and play a role in determining properties of structural membranes. The effect of dietary essential fatty acids, linoleic acid (18 : 2 (n - 6)) and alpha-linolenic acid (18 : 3 (n - 3)), on the saturated fatty acid content of membrane phospholipid has not previously been considered in newborn nutrition. The studies report the effect of low (1% fatty acids) or high (4%) formula 18 : 3 (n - 3) with low (16%) or high (30-35%) formula 18 : 2 (n - 6) on the saturated and unsaturated fatty acid composition of liver and brain structural lipid of piglets fed formula from birth for 15 days. A significant inverse relationship between the formula % 18 : 3 (n - 3), but not 18 : 2 (n - 6), and the liver phospholipid palmitic acid (16 : 0) was found. This may indicate a possible effect of dietary 18 : 3 (n - 3) on de novo synthesis of 16 : 0 and requires further investigation. Monounsaturated fatty acids in both liver and brain were significantly lower in response to high 18 : 3 (n - 3) and to high 18 : 2 (n - 6) plus low 18 : 1 (n - 9) in the formula. Liver phospholipid and brain total lipid % docosahexaenoic acid (22 : 6 (n - 3)) were significantly higher when formula containing 4% rather than 1% 18:3 (n - 3) was fed, suggesting that 1% 18 : 3 (n - 3) may limit tissue (n - 3) fatty acid accretion. These results suggest that future studies of essential fatty acid requirements, specifically 18 : 3 (n - 3), should consider possible influences on the saturated fatty acids which also play a functional role in tissue structural lipids.