Cholesterol lowering benefits of soy and linseed enriched foods
Cholesterol lowering benefits of soy and linseed enriched foods
Year: 2001
Authors: Ridges, L. Sunderland, R. Moerman, K. Meyer, B. Astheimer, L. Howe, P.
Publication Name: Asia Pacific J. Clin. Nutr.
Publication Details: Volume 10; Number 3; Pages 204 � 211.
Abstract:
Foods such as breads and breakfast cereals enriched with a combination of soy protein (soy grits and/or soy flour) and whole linseed are gaining popularity. Regular consumption of either whole grains or soy protein can lower risk factors for coronary heart disease. Furthermore, linseed is a rich source of the omega-3 fatty acid, α-linolenic acid (LNA), with purported cardiovascular benefits. The aim of this study was to determine the effect of daily consumption of soy and linseed containing foods and Canola (as an added source of LNA) on plasma lipid concentrations in 20 mildly hypercholesterolaemic postmenopausal women. Fasted blood samples were taken initially and after 3 and 8 weeks to assay plasma lipids and both plasma and erythrocyte membrane fatty acids. Urinary isoflavones were also measured. Data from 18 subjects were used for analysis. Plasma total, low-density lipoprotein (LDL) and non-high-density lipoprotein (HDL) cholesterol concentrations fell significantly (10, 12.5 and 12%, respectively) within 3 weeks. Although attenuated, there were still significant reductions in total and non-HDL cholesterol (5 and 6.5%, respectively) after 8 weeks of intervention. These reductions were associated with increases in urinary isoflavone excretion. This pilot study indicates that regular inclusion of foods containing soy and linseed in the diet may improve plasma lipids in subjects with hypercholesterolaemia. (Author�s abstract)
In Australia, there has been no evaluation of the potential cardiovascular health benefits of foods soy and linseed ingredients.
Epidemiological research shows that in many countries. The aim of this study was to conduct a preliminary evaluation, in mildly hyperlipidaemic postmenopausal women, of the potential lipid-lowering benefits of regular daily consumption of soy and linseed containing foods together with additional dietary sources of LNA. The primary finding of this study was that daily consumption of soy and linseed containing foods and Canola by mildly hypercholesterolaemic women resulted in clinically significant improvements of plasma cholesterol after 3 weeks. The reductions of total, LDL and non-HDL cholesterol were not transient but were still evident after 8 weeks of continuous dietary supplementation. The authors hypothesised that the flaxseed gums and components contained within the whole flaxseed may contribute to cholesterol reduction by increasing bile acid excretion with increased laxation, or through lignan modulation of cholesterol metabolising enzymes. They also attribute the change in dietary P:S ratio from the increased ALA intake as a contributing factor. This study has demonstrated the feasibility of supplementing the diet with soy and linseed containing foods to achieve clinically useful reductions of total, LDL and non-HDL cholesterol. However, the specific dietary factors and mechanisms responsible for the favourable lipid change are unclear. The results highlight the potential to design foods with appropriate combinations of active nutrients to optimise dietary prevention and treatment of cardiovascular risk factors in populations with an elevated risk of developing cardiovascular disease. (Editor�s comments)
