The Influence of Different Types of n-3 Polyunsaturated Fatty Acids on Blood Lipids and Platelet Function in Healthy Volunteers.
The Influence of Different Types of n-3 Polyunsaturated Fatty Acids on Blood Lipids and Platelet Function in Healthy Volunteers.
Year: 1983
Authors: T A B Sanders, F Roshanai.
Publication Name: Clin. Sci.
Publication Details: Volume 64; Page 91
Abstract:
In this early study, the investigators were interested in determining the effects on blood lipids and platelet function of various oils containing ALA, EPA and DHA. Two experiments were conducted. In the first experiment, five healthy subjects took a daily supplement of 20 ml of flaxseed oil (containing 9.38 g of ALA) for 2 weeks. After a washout period of at least 6 weeks, the same subjects took a similar amount of MaxEPA (18% EPA, 3.03 g and 12% DHA, 2.93 g) for 2 weeks. The effects of the supplements on plasma lipid concentrations and on the FA composition of platelet PLs were studied. In a second experiment, five male subjects took 5, 10 and 20 g of MaxEPA/day in random order for 3 week periods with each experimental period separated by a washout period of at least 6 weeks. These doses of MaxEPA provided 0.83, 1.67 and 3.33 g of EPA and 0.80, 1.61 and 3.22 g of DHA, respectively. Effects on plasma lipid concentrations, the FA composition of platelet PLs, bleeding time and platelet aggregation induced by collagen and the prostaglandin analogue compound, U46619, were assessed. The results showed that the proportion of EPA in platelet lipids was increased by the flaxseed oil, although the enhancement was smaller than following the MaxEPA supplement. The ratio of AA:EPA decreased from 50:1 following the control periods to 20:1 following the flaxseed oil supplementation period. The proportion of AA was significantly decreased by the MaxEPA supplement and slightly lowered by the flaxseed oil supplement. The ratio of AA:EPA decreased from 31:1 following the control periods to 11:1 with 5 g, 7:1 with 10 g and 5:1 with 20 g of MaxEPA/day. The MaxEPA supplement also led to increases in the proportions of DPA and DHA and decreases in 20:3n-6. Bleeding times tended to be prolonged with the MaxEPA supplement but did not follow a dose-dependent trend. The authors attributed enhanced bleeding times to alterations in eicosanoid synthesis, in particular reductions in platelet aggregator agents such as PGE2 and TXB2. Unlike previous studies with n-3 oil supplements, platelet aggregation induced by collagen and U46619 was not inhibited in vitro by either the flaxseed oil or MaxEPA supplements. Plasma TG concentrations were significantly decreased by 10 g and 20 g of MaxEPA/day. Plasma TC concentrations were slightly lowered, and HDL-C concentrations were slightly increased, by 20 g of MaxEPA/day. No other significant differences were noted. The authors concluded that n-3 PUFAs can significantly influence blood lipid patterns and haemostatic function.
