Plasma Fatty Acid Pattern Including Diene‐Conjugated Linoleic Acid in Ethanol Users and Patients with Ethanol‐Related Liver Disease

The level of conjugated dienes (CO) in the serum, conjugated linoleic acid isomer in the phospholipid fraction [18:2(9,11)], and the fatty acid profile in both the serum and in the separated lipid classes were analyzed in current and previous alcohol abusers and in patients with alcoholic liver disease. None of the subjects consumed alcohol for at least 2–3 days prior to blood collection for analysis of lipids. There was no significant difference in CD or in the absolute level of 18:2(9,11) among the groups, whereas the 18:2(9,11)/ 18:2(9,12) molar ratio was significantly elevated in patients with liver disease. Fatty acid analysis of the whole plasma extract showed that the absolute level of arachidonic acid increased from 4.8 ± 3.5 mg/dl (n= 9) in lifelong abstainers to 13.4 ± 4.0 (n= 8) in current ethanol abusers, and its relative level (related to the total fatty acids) from 1.73 ± 1.34 to 4.55 ± 1.01 in the same groups. An increased proportion of linoleic acid in the triglyceride and phospholipid fractions from current abusers and patients with liver disease was also found; the percentage of 18:2 in phospholipids increased from 5.4 ± 5.0 (n = 8) in lifelong abstainers to 14.3 ± 3.9 (n = 8) in current abusers and 12.7 ± 2.2 (n = 10) in patients with Hver disease. The percentage of 16:0 was significantly lower in the phospholipids of current abusers as compared to lifelong abstainers. These data confirm earlier findings on increased free radical activity in liver diseases, and a lack of it in chronic alcoholics (unless they consume alcohol 1–2 days before the test). The fatty add profiles suggest a relative accumulation of long chain fatty acids induced by ethanol, conceivably due to a differential effect of ethanol on the β‐oxidation and esterificatjon of fatty acids according to their chain length. The observed changes may be useful in biochemical diagnosis of alcohol use.