Alpha-Linolenic Acid and Marine Long-Chain n-3 Fatty Acids Differ Only Slightly in their Effects on Hemostatic Factors in Healthy Subjects.
Alpha-Linolenic Acid and Marine Long-Chain n-3 Fatty Acids Differ Only Slightly in their Effects on Hemostatic Factors in Healthy Subjects.
Year: 1997
Authors: R Freese, M Mutanen.
Publication Name: Am. J. Clin. Nutr.
Publication Details: Volume 66; Number 3; Page 591.
Abstract:
The protective effect of ALA on coronary heart disease risk factors appears to include a reduction in thrombogenesis but few studies have directly studied this relationship. In this study, the effects of ALA, EPA and DHA on hemostatic factors including platelet function, factor VIIc, fibrinogen, antithrombin III (AT-III) activity, and plasminogen activator inhibitor 1 (PAI-1), were assessed. Healthy subjects (29 women and 17 men, aged 20-44 years) consumed their habitual diets to which a supplement of either flaxseed oil (average ALA intake: 5.9 g/day) or fish oil plus sunflower oil (average EPA + DHA intake: 5.2 g/day) was added for 4 weeks. The supplemented fat amounted to 1 g/200 kcal calculated energy expenditure. Blood samples were collected at baseline, at the end of the experimental period, and after a 12 week follow-up period. Differences between the two groups were noted only in TC and TGs, platelet FA composition, and ADP-induced platelet aggregation. Supplementation flaxseed oil increased the level of ALA in platelet lipids. Significant reductions in platelet levels AA of 4% in the flaxseed oil group and 16% in the fish oil group were noted. EPA levels increased by 17% and 115% in the flaxseed oil and fish oil groups, respectively. DPA levels were 18% higher in the flaxseed oil group and 43% higher in fish oil group. The flaxseed oil supplement did not significantly increase DHA levels whereas an increase of 39% was noted following the fish oil supplement. TC and TG levels were reduced by the fish oil supplement only. The treatments did not differ in their effects on collagen-induced platelet aggregation and TXB production, aggregation to the TXA2 mimic I-BOP, urinary excretion of 11-dihydro-thromboxane B2 and beta-thromboglobulin, bleeding time, plasma fibrinogen concentration, antithrombin III activity, factor VII coagulant activity, or activity of PAI-1. Bleeding time reflects the function of primary hemostasis, mainly platelet function. In this study, bleeding time was enhanced similarly by supplementation with ALA and EPA plus DHA. The authors concluded that ALA from flaxseed oil has similar effects on various hemostatic factors as do EPA and DHA from marine sources. They indicated that vegetable oils rich in ALA are valuable sources of n-3 PUFAs and more controlled studies are needed to establish the effects of ALA on hemostatic factors.
