The effect of various intakes of ω3 fatty acids on the blood lipid composition in healthy human subjects

Abstract

In a study with 52 healthy volunteers, the effect of different amounts of omega 3 fatty acids on the blood lipid composition was investigated. Doses of 1.4, 2.3, 4.1, and 8.2 g of omega 3 fatty acids were administered to these subjects daily over a period of 4 wk. Total cholesterol, high-density lipoprotein cholesterol, total triglycerides, and glucose were determined in blood serum and hemoglobin in whole blood in all individuals before, during, and after the intake of omega 3 fatty acids. In pooled serum samples, the lipoprotein composition and the fatty acid composition of blood lipids were determined. All dosages caused a shift in the fatty acid composition of blood serum lipids in a favor of omega 3 fatty acids and at the expense of omega 6 and/or omega 9 acids. In the sterol esters, only the percentage of C20:5 omega 3 increased. Maximum shifts depended on the amount of omega 3 acids ingested and were evident within 1 to 2 wk. Two wk after the last ingestion of omega 3 acids, the fatty acid composition of blood serum lipids had returned to the original state. In the groups receiving 8.2 of omega 3 fatty acids, there was a significant decrease in serum triglyceride and very low-density lipoprotein levels, which is in accord with earlier observations. In the other parameters, including cholesterol and high-density lipoprotein cholesterol, no decrease or increase was observed.

Polyunsaturated fatty acids, hyperlipidemia, and thrombosis.

“…Possible mechanisms for this effect will be discussed subsequently. The fact that HDL levels were not depressed has been confirmed by others, 91 and, in some studies, HDL cholesterol levels have actually increased on the co-3 fatty acid rich diets. 90 ' T he effects of fish oils in hypercholesterolemic and hypertriglyceridemic patients have been reported in Control Salmon oil Vegetable oil Figure 2.…”

“…86 ' M In a second study, however, the addition of up to 8 g of co-3 fatty acids (from cod liver oil) did not change the plasma cholesterol levels but did result in a significant reduction in plasma triglycerides. 91 A further study showed that 4 g of co-3 fatty acids per day were able to reduce the levels of plasma triglycerides but not of cholesterol. 92 A major problem with many of these studies is that the fish oils were simply given as supplements and were not incorporated into a metabolic diet as a replacement for a portion of the customary dietary fat.…”

“…38 ' 9°. 91 • 93 The percent of total fatty acids occurring as co-3 in each class of plasma lipids (triglyceride, phospholipid, and cholesteryl esters) was 1 % to 3% on the control diet and increased to 31%, 33%, and 26%, respectively, after the co-3 diet. 93 Since these co-3 fatty acids are highly unsaturated (5 to 6 double bonds), the fluidity of the lipoprotein particles would probably be affected 6495 and the interaction between lipoproteins and lipolytic enzymes may be enhanced.…”

Evidence for altered positional specificity of LCAT in vivo

“…Because DHA is found exclusively at the sn-2 position of PC, ‫ف‬ 10% of all plasma PC molecules contained DHA after supplementation, whereas only ‫ف‬ 1.2% of CE contained DHA. Thus, there was a disproportionate increase of DHA in PC, compared with CE, as reported in other studies in humans (10,20,21) and in experimental animals (22) after fish oil supplementation.…”

Continual supplementation with n-3 fatty acids does not modify plasma lipid profile in spinal cord injury patients

“…A diet rich in n-3 PUFAs reduce the plasma concentration of VLDLc. [15][16][17] Most of the research conducted on PUFAs has focused on EPA and DHA. These PUFAs are found in varying concentrations in fish products.…”