Essential fatty acid status in adult patients receiving soybean-base formula

Essential fatty acid (EFA) status was assessed in 48 normal Thai adults and 6 patients who required tube feeding ro 2-4 wk with commercial soybean-base formula (Sobel, Mead Johnson). Each 1000 kcal of this formula provided 40.2 g protein, 32.8 g fat, 136 g carbohydrate, 13.9 g linoleic acid, 2.9 g linolenic acid, and 0 g arachidonic acid. The linoleic acid status in these patients before receiving soybean-base formula was inadequate, as evidenced by the significantly lower serum 18:2-W6 percentage but higher serum 16:1-W7 and 18:1-W9 percentages than those in normal adults. These changes were reversed while receiving soybean-base formula. A significant positive correlation between linoleic acid intake and its serum level was demonstrated. There was a significant decrease in serum 20:4-W6 percentage while receiving soybean-base formula. This could be related to the absence of this EFA in the formula and suppression of biotransformation of 18:2-W6 to 20:4-W6 in the presence of a significant amount of 18:3-W3. None of the patients had 20:3-W9 in the serum or developed scaly dermatitis throughout the study.