Flaxseed dietary fibers suppress postprandial lipemia and appetite sensation in young men.
Flaxseed dietary fibers suppress postprandial lipemia and appetite sensation in young men.
Year: 2011
Authors: Kristensen, M. Savorani, F. Christensen, S. Engelsen, S.B. Bugel, S. Toubro, S. Tetens, I. Astrup, A.
Publication Name: Nutr. Metab. Cardiovasc. Dis.
Publication Details: Jul 27; Pages 1 – 8
Abstract:
Dietary fibers (DF) are linked to a reduced risk of life-style diseases, which relate to their physiological effects in the gastrointestinal tract. The aim was to examine whether flaxseed DF-enriched meals suppress postprandial lipemia and reduce appetite. Four different iso-caloric meals were tested in 18 young men in a double blind randomized crossover design. Test meals were served after an overnight fast. DF content and source were: control (C): 1.4 g/MJ; whole flaxseed (WF): 2.4 g/MJ from whole flaxseeds; low-mucilage dose (LM): 2.4 g/MJ from flaxseed DF; high-mucilage dose (HM): 3.4 g/MJ from flaxseed DF. During the 7 h test day, subjective appetite sensation was assessed using visual analogue scales and appetite-regulating hormones, and lipemia and glycemia were measured, after which ad libitum energy intake was recorded. There was a significant time meal effect on triacylglycerols (TG) (p < 0.02) and an 18% smaller area under the curve (AUC) for TG after meal HM compared to meal C was observed (p < 0.01). AUC for insulin was smaller after both LM and HM meals compared to C and WF meals. Higher mean ratings of satiety (p < 0.01) and fullness (p <0.03) was seen following the HM meal compared to meal C. AUC for ghrelin, CCK and GLP-1 and ad libitum energy intake did not differ between meals, but ghrelin response exhibited a different response pattern after the mucilage-containing meals. These findings suggest that flaxseed DF may suppress postprandial lipemia and appetite although subsequent energy intake was not affected. [Authors abstract]
Elevated postprandial triacylglycerol (TG) concentrations are being recognized as an independent predictor of heart disease. To suppress not only fasting TG concentrations but also the postprandial rise in TG may be effective to prevent the development of CVD. Some viscous DF are capable of lowering the postprandial TG response. Flaxseeds contain about 30% DF of which 70-80% is water-soluble. The majority of these are present on the outside of the seed coat (the mucilage). In this study, flaxseed DF suppressed the postprandial lipemic response, suggesting they may also be of relevance for maintenance of a healthy body weight through limited nutrient absorption. DF is helpful in in weight control because of their satiating effect thereby lowering energy intake. In this study, 2 g/MJ of flaxseed DF also induced significant effects on subjective appetite sensation. Apart from a potential direct fat-binding, apparent viscosity of flaxseed DF may also play a role in increased postmeal satiety. In the present study, the subjective measures of appetite were however not accompanied by decreased energy intake at the following lunch meal after DF consumption. The time between the test meal and the ad libitum lunch meal was 7 h, which may have limited the ability to detect differences in energy intake, as the participants were as hungry or even more so as compared to the fasted state. An inhibitory effect of flaxseed DF on the hunger-signaling hormone ghrelin was seen throughout the test day. Although no significant effect on CCK was observed, the postprandial pattern resemble that of postprandial ghrelin suggesting a prolonged effect on satiety signaling with viscous DF. Also a numerical increase in AUC for CCK with increasing fiber dose was seen, which suggests a dose-response relationship. To conclude, these results point toward a potential of purified flaxseed DF to moderate several risk factors through effects on lipid metabolism as well as appetite regulation. Further research is required to substantiate the observed effects in body weight and cardiovascular risk in the longer term. [Editors comments]
Elevated postprandial triacylglycerol (TG) concentrations are being recognized as an independent predictor of heart disease. To suppress not only fasting TG concentrations but also the postprandial rise in TG may be effective to prevent the development of CVD. Some viscous DF are capable of lowering the postprandial TG response. Flaxseeds contain about 30% DF of which 70-80% is water-soluble. The majority of these are present on the outside of the seed coat (the mucilage). In this study, flaxseed DF suppressed the postprandial lipemic response, suggesting they may also be of relevance for maintenance of a healthy body weight through limited nutrient absorption. DF is helpful in in weight control because of their satiating effect thereby lowering energy intake. In this study, 2 g/MJ of flaxseed DF also induced significant effects on subjective appetite sensation. Apart from a potential direct fat-binding, apparent viscosity of flaxseed DF may also play a role in increased postmeal satiety. In the present study, the subjective measures of appetite were however not accompanied by decreased energy intake at the following lunch meal after DF consumption. The time between the test meal and the ad libitum lunch meal was 7 h, which may have limited the ability to detect differences in energy intake, as the participants were as hungry or even more so as compared to the fasted state. An inhibitory effect of flaxseed DF on the hunger-signaling hormone ghrelin was seen throughout the test day. Although no significant effect on CCK was observed, the postprandial pattern resemble that of postprandial ghrelin suggesting a prolonged effect on satiety signaling with viscous DF. Also a numerical increase in AUC for CCK with increasing fiber dose was seen, which suggests a dose-response relationship. To conclude, these results point toward a potential of purified flaxseed DF to moderate several risk factors through effects on lipid metabolism as well as appetite regulation. Further research is required to substantiate the observed effects in body weight and cardiovascular risk in the longer term. [Editors comments]
