The effect of feeding fish oil (Menhaden) on the progression of rhesus monkey atherosclerosis was determined by feeding diets containing 2% cholesterol and either 25% coconut oil (Group I), 25% fish oillcoconut oil (1:1) (Group II), or 25% fish oillcoconut oil (3: 1) (Group III) for 12 months (n =8/group). The average serum cholesterol levels were 875 mg/dl for Group I, 463 mg/dl for Group II, and 405 mg/dl for Group III. HDL cholesterol levels were 49 mgldl for Group I, 29 mg/dl for Group II, and 20 mg/dl for Group III. An average of 79% of the aortic intima was involved with atherosclerosis in Group I, 48% in Group II, and 36% in Group III. The aortas of both fish-oil groups (II or 111) contained significantly less cholesterol (total, free, and esterified), as well as less acid lipase, cholesteryl esterase, and ACAT activities when compared to the coconutoil group (I) (p< 0.05). Microscopically, the aortic and carotid artery lesions were smaller in cross-sectional area and in thickness, and contained less macrophages in the fish-oil groups (II and 111) when compared to the coconut-oil group (I) (p< 0.05).This protective effect was not consistently enhanced by increasing the proportion of fish oil to 3: 1 (Group III) over 1:1 (Group II). The results indicate that fish oilcontaining diets reduce serum cholesterol levels and inhibit atherosclerosis even in the face of lowered HDL cholesterol levels when compared to a pure coconut oillcholesterol diet in rhesus monkeys. Therefore, fish-oil diets exert effective protective control of progression of atherosclerosis during severe atherogenic stimuli.
Arteriosclerosis – Wolters Kluwer Health
Published: Sep 1, 1987