PATIENTS WITH ANOREXIA-NERVOSA DEMONSTRATE DEFICIENCIES OF SELECTED ESSENTIAL FATTY-ACIDS, COMPENSATORY CHANGES IN NONESSENTIAL FATTY-ACIDSAND DECREASED FLUIDITY OF PLASMA-LIPIDS

The objective of this study was to assess the essential fatty acid sta tus of patients with anorexia nervosa. Blood was collected from eight fasting female anorexia nervosa patients with a mean of 81% ideal body weight. Fatty acid composition of phospholipids, nonesterified fatty acids, triglycerides and cholesteryl esters of plasma were determined by capillary gas chromatography to indicate polyunsaturated fatty acid s status compared with 19 healthy female adults <25 y old. Subjects wi th anorexia nervosa showed polyunsaturated fatty acid deficiencies in plasma phospholipids different from simple nutritional essential fatty acid deficiency or chronic malnutrition. The phospholipid profile sho wed significantly lower (n-6) and (n-3) elongation and desaturation pr oducts, and elevated short-chain saturated, short-chain monounsaturate d, branched-chain and odd-chain fatty acids. These elevations indicate enhancement of biosynthesis of alternative fatty acids that only part ially compensated for the loss of polyunsaturated fatty acids in provi ding membrane ''fluidity.'' Calculated mean melting point of the fatty acids of phospholipids in patients with anorexia nervosa was elevated 7.7 degrees C above normal values. These results demonstrate that pat ients with anorexia nervosa have deficiencies of selected essential fa tty acids, compensatory changes in nonessential fatty acids decreased fluidity of plasma lipids.