The effect of dietary alpha-linolenic acid on blood lipids and lipoproteins in humans.
The effect of dietary alpha-linolenic acid on blood lipids and lipoproteins in humans.
Year: 1995
Authors: G J Nelson, J G Chamberlain.
Publication Name: Flaxseed in Human Nutrition. ed. S.C. Cunnane and L.U. Thompson, AOCS Press, Champaign, Il.
Publication Details: Page 187.
Abstract:
Oleic acid and LA have been shown in several metabolic studies to lower serum total and LDL cholesterol in humans, whereas the effects of ALA on these lipid fractions has been inconsistent. Clinical and epidemiological evidence has established that dietary n-3 PUFA consumption is associated with reduced risk of cardiovascular disease and all-cause mortality. The ability of n-3 PUFAs to alter the production of inflammatory and aggregatory eicosanoids is well supported by both animal and human studies. Within the last few years, emphasis has been focused upon the role of n-3 PUFAs in lowering serum lipid levels. In this chapter, the authors reports that dietary supplementation of ALA in the form of flaxseed oil (six studies) and flaxseed (three studies) results in significant conversion of ALA to EPA within platelet cells. ALA and EPA levels in blood plasma or serum lipid fractions consistently increased with increasing levels and duration of flaxseed oil and/or flaxseed supplementation. In addition, decreases in LA and AA were noted in the studies conducted with flaxseed oil. These findings indicate that ALA can serve as a source of EPA in the body and therefore, can supply the precursor of the series 3 and 5 eicosanoids. The authors also review seven studies in which the effects of flaxseed and flaxseed oil on serum lipids and lipoproteins were examined in human subjects. In these investigations, flaxseed oil was shown to lower TG, but did not produce consistent changes in TC and LDL-C levels. The feeding of flaxseed was reported to decrease TC and LDL-C, affect no change in HDL-C and produced inconsistent changes in TG. flaxseed also contains fiber and mucilage and these components may have contributed to lipid lowering effects.
