The acute effect of a single very high dose of N-3 fatty acids on coagulation and fibrinolysis.

The objective of the study was to investigate the acute effect of a single very high dose of n-3 PUFA on coagulation and fibrinolysis. Forty healthy volunteers were randomized into two groups to receive either 20 grams of n-3 PUFA or 20 grams of n-6 PUFA as a single dose at 6 p.m. with their evening meal. Coagulation and fibrinolysis were evaluated in the fasting state at 8 a.m. the next morning and compared to values obtained at 8 a.m. the day before, when the participants were on their habitual diets. PAI-1 activity in plasma increased by a mean of 62% in subjects randomized to receive n-3 PUFA despite that no changes could be demonstrated in t-PA antigen levels. PAI-1 activity was unaltered in the 20 controls receiving n-6 PUFA. Plasma fibrinogen, coagulation factor VII, thrombin-antithrombin complexes and D-dimer did not significantly change after either supplement. The substantial increase in levels of PAI-1 activity in plasma after a single very high dose of n-3 PUFA may limit the usefulness of single very high doses of n-3 PUFA in acute clinical conditions.

The acute effects of a single very high dose of n-3 fatty acids on plasma lipids and lipoproteins in healthy subjects.

Forty healthy volunteers were allocated in a double blind, randomized study to receive either 20 g of n-3 polyunsaturated fatty acids (PUFA) or 20 g of n-6 PUFA at their evening meal. The effect on plasma lipids and lipoproteins of this single dose of fish oil vs. corn oil was studied the next morning, 14 h after ingestion. Plasma triglycerides and very low density lipoprotein-cholesterol significantly decreased (33%) after n-3 PUFA (P < 0.001), and significantly (P < 0.01) more than after intake of n-6 PUFA. The decrease in plasma triglycerides after n-3 PUFA ingestion was more pronounced in subjects with higher baseline levels of triglycerides (P < 0.001). Total cholesterol decreased after both supplements, but did not differ between the supplements. Low density lipoprotein-cholesterol did not change, and high density lipoprotein-cholesterol significantly decreased in subjects given n-3 PUFA compared to baseline, but not when compared to subjects receiving n-6 PUFA. In conclusion, we have shown that a single very high dose of n-3 PUFA has a pronounced hypotriglyceridemic effect, which is directly related to the initial plasma level.

n-3 polyunsaturated fatty acid supplementation (Pikasol) in men with moderate and severe hypertriglyceridaemia: a dose-response study.

The effect of n-3 fatty acids in 11 men with hypertriglyceridaemia was investigated. The subjects were given daily supplements with three different doses of n-3 fatty acids for 8-week periods. The supplements given were 2, 4 and 9 g of n-3 fatty acids/day, respectively. Total cholesterol, triglycerides and the ratio of total cholesterol to HDL-cholesterol significantly decreased with all three doses in a dose-dependent way. HDL-cholesterol increased in a dose-dependent fashion, while apolipoproteins A1 and B were unaltered by the supplements apart from a small increase in apolipoprotein A1 after the lowest dose of n-3 fatty acids. The greatest effect was observed after 2 g of n-3 fatty acids/day.

The effect of low-dose supplementation with n-3 polyunsaturated fatty acids on some risk markers of coronary heart disease.

Epidemiological data have suggested that a low dose of dietary n-3 polyunsaturated fatty acids from seafood may protect against coronary heart disease. We studied the effect of supplementation with a low dose of very long-chain n-3 fatty acids (0.65 g day-1) on plasma lipids, haemostasis, and neutrophil aggregation. Twenty-four healthy subjects were randomized to supplementation with very long-chain n-3 fatty acids or a control oil for 8 weeks. Laboratory analyses were done twice before and twice at the end of the supplementation period. The supplement with n-3 polyunsaturated fatty acid did not significantly affect plasma lipids or plasma levels of fibrinogen, factor VII, plasminogen activator inhibitor, whole blood aggregation or aggregability of neutrophil leukocytes. Therefore, the potential beneficial effect of very long-chain n-3 fatty acids in coronary heart disease is likely to be mediated through other mechanisms.

The effect of n-3 fatty acids on neutrophil chemiluminescence.

The effect of dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) on the production of free oxygen radicals from activated neutrophils was investigated in healthy subjects, using chemiluminescence. In the first study 22 persons were give 4 g n-3 PUFAs daily for 6 weeks. There was a median reduction of chemiluminescence from neutrophils stimulated with opsonized zymosan of 37% (p < 0.001). The median content of eicosapentaenoic acid in platelets, used as an indicator for cellular fatty acid profile, increased from 0.70 to 2.80% (p < 0.001), and there was a significant negative correlation between the chemiluminescence signal and the content of eicosapentaenoic acid in platelets (p < 0.001). In a second, low-dose study 24 persons were allocated to daily supplementation with either 0.65 g n-3 PUFAs or with a control oil for 6 weeks. Compared to the control group there was a median reduction of 38 and 44% in chemiluminescence from neutrophils stimulated with opsonized zymosan and phorbol,12-myristate,13-acetate (PMA), respectively. Neither of these differences, however, was statistically significant. These findings lend support for a possible role of n-3 PUFAs in the management of inflammatory disorders.