EFFECTS OF 2 TYPES OF FISH OIL SUPPLEMENTS ON SERUM-LIPIDS AND PLASMA PHOSPHOLIPID FATTY-ACIDS IN CORONARY-ARTERY DISEASE

Fish oil has consistently been shown to lower triglyceride levels, but its effects on low-density lipoprotein (LDL) cholesterol remain controversial. The current study compares the long-term effects of 2 different fish oil preparations (ethyl ester and triglyceride) versus olive oil in patients with coronary artery disease. Eighty-nine subjects were randomly assigned to receive capsules containing 6 g/day (triglyceride group) or 7 g/day (ethyl ester group) of n-3 fatty acids, or capsules containing 12 g/day of olive oil for 6 months. Mean triglyceride levels decreased by 28% in the ester and 32% in the triglyceride fish oil groups (p < 0.05 for both). LDL cholesterol levels increased by 3% (difference not significant) in the ester and 12% (p < 0.05) in the triglyceride fish oil groups; in hypertriglyceridemic subjects the increase was 23% (p < 0.01) and 14% (difference not significant), respectively. Plasma phospholipid fatty acid analysis showed a fivefold increase in eicosapentaenoic acid levels in both fish oil groups (p < 0.001), and a long-term decrease in arachidonic acid levels (p < 0.001). Achieved eicosapentaenoic acid level correlated with the degree of increase in LDL cholesterol (r = 0.38, p < 0.05). These data suggest that fish oil administration is associated with an increase in LDL cholesterol levels in a diverse group of patients with coronary artery disease; this change appears to be correlated with n-3 fatty acid absorption. The impact of this increase in LDL is unknown, but should be considered as potentially adverse. © 1990.