Replacement of Linoleic Acid with Alpha-Linolenic Acid does not Alter Blood Lipids in Normolipidaemic Men.
Replacement of Linoleic Acid with Alpha-Linolenic Acid does not Alter Blood Lipids in Normolipidaemic Men.
Year: 1998
Authors: D Pang, M A Allman-Farinelli, T Wong, R Barnes, K M Kingham.
Publication Name: Br .J. Nutr.
Publication Details: Volume 80; Number 2; Page 163.
Abstract:
Previous studies have shown that the type of dietary fat ingested is a major factor influencing plasma lipid profiles. Interest in increasing the consumption of the n-3 family of PUFA has grown since studies of Greenland Eskimos showed low incidence of coronary heart disease, despite high fat intakes which included large amounts of the very-long-chain n-3 fatty acids, eicosapentanoic (EPA) and docosahexanoic (DHA) acid. Research involving the effects of the n-3 PUFA a-linolenic acid (ALA) on blood lipids have been reported but are difficult to interpret because other factors such as OA intake have not been well controlled. OA has been shown to lower blood cholesterol levels. The objective of this study was to establish the precise effects of ALA on blood lipids. In part, this research was deemed necessary because of the marked reduction in myocardial infarction that has been shown following high ALA intakes. After a 2-week stabilization period, 29 healthy young men were randomly assigned to either an ALA-rich group (mean of 10.1 g of ALA and 12.1 g of LA/day) or a LA-rich diet group (1.0 g ALA and 21.0g LA/day). ALA and LA were manipulated by replacing safflower oil (LA-rich) with flaxseed oil (ALA-rich). Subjects consumed 32% energy as fat with 10% as SFA and 7% as PUFA. After 6 weeks, there were no significant differences reported between the two dietary groups in plasma TC, LDL-C, HDL-C, subfractions HDL2 and HDL3, and TG. The authors postulated that the benefits of ALA are more likely to be seen in individuals with thrombotic tendency or arrythmias rather than healthy subjects. The findings suggest that in normolipidemic subjects, ALA has similar effects on blood lipids as LA. The authors indicated that this data should not be extrapolated to hyperlipidemic subjects. The authors conclude that because no deleterious effects were seen in this study, there is support to include ALA in the diet. Replacing LA with ALA in the diet of healthy males can have similar cardioprotective benefits with respect to lipid metabolism. Other studies are needed to explore the benefits of ALA on other variables that affect cardiovascular disease as many studies have demonstrated a positive association between ALA intake and reductions in coronary heart disease.
