Nutritional Attributes of Traditional Flaxseed in Healthy Young Adults.
Nutritional Attributes of Traditional Flaxseed in Healthy Young Adults.
Year: 1994
Authors: S C Cunnane, M J Hamadeh, A C Liede, L U Thompson, T M S Wolever, D J A Jenkins.
Publication Name: Am. J. Clin. Nutr.
Publication Details: Volume 61; Page 62.
Abstract:
Previous studies have assessed the effects of flaxseed oil on serum lipids, FA composition and platelet function. However, high amounts of flaxseed oil (10 – 60 g/day) were used, levels which would be difficult to incorporate into a daily diet. These studies were also of short duration, usually 2 weeks or less. Although flaxseed appears to have very beneficial health effects, its high oil content (350 – 400 g/kg flaxseed) and polyunsaturation (720 g/kg oil) may give rise to lipid peroxides and reduce antioxidants. In this study, the effects of flaxseed consumption on tissue FA composition, serum lipids, urinary lignan excretion, antioxidant and peroxide levels in plasma and laxation were assessed. The study followed a randomized design in which the typical diets of ten healthy volunteers were supplemented with 50 g of flaxseed/day in the form of muffins (total ALA of 9 g/day) for 4 weeks or with the same muffins prepared without flaxseed. For the male subjects, a washout period of 2 weeks separated the treatments. For the female subjects, the second feeding period was structured to correspond with the same phase of the menstrual cycle as during the first feeding period, resulting in washout periods of 3 to 5 weeks. Baking did not have an affect on lipid breakdown in the muffins. Control muffins and muffins containing 25 g flaxseed did not differ significantly in their content of thiobarbituric acid-reactive substances. The ALA levels of the flaxseed muffins were not significantly reduced by baking. The flaxseed diets resulted in significant increases in the levels of ALA in adipose tissue. ALA, EPA and DPA were significantly increased in plasma PLs and TGs compared to control values. Plasma TC and LDL-C decreased significantly by 6% and 9%, respectively. Plasma HDL-C and TG did not change. Total urinary lignan excretion was significantly increased more than five-fold when the subjects consumed the flaxseed diet. Antioxidant vitamins (retinol, ?- and ?-tocopherols) and lipid hydroperoxides in plasma were not significantly affected by flaxseed consumption. Lignans have been shown to have antioxidant effects that may have contributed to this result. Laxation was improved with flaxseed feeding. Bowel movements per week increased significantly by 30% during the flaxseed supplementation period. The authors concluded that traditional flaxseed has beneficial effects on several indexes of nutritional status including laxation, plasma lipids, n-3 PUFA levels in plasma and adipose tissue, and lignan concentrations. In the present study, 50 g/day of flaxseed did not compromise antioxidant status. The authors recommended further studies aimed at assessing the use of flaxseed in the management of cardiovascular risk factors.
