Effect of fatty acid chain length and saturation on the gastrointestinal handling and metabolic disposal of dietary fatty acids in women

Abstract

The gastrointestinal handling and metabolic disposal of [1-13 C]palmitic acid, [1-13 C]stearic acid and [1-13 C]oleic acid administered within a lipid-casein-glucose-sucrose emulsion were examined in normal healthy women by determining both the amount and nature of the 13 C label in stool and label excreted on breath as 13 CO 2 . The greatest excretion of 13 C label in stool was in the stearic acid trial (9 . 2 % of administered dose) whilst comparatively little label was observed in stool in either the palmitic acid (1 . 2 % of administered dose) or oleic acid (1 . 9 % of administered dose) trials. In both the palmitic acid and oleic acid trials, all of the label in stool was identified as being present in the form in which it was administered (i.e. [13 C]palmitic acid in the palmitic acid trial and [13 C]oleic acid in the oleic acid trial). In contrast, only 87 % of the label in the stool in the stearic acid trial was identified as [13 C]stearic acid, the remainder was identified as [ C]stearic acid within the gastrointestinal tract. Small, but statistically significant, differences were observed in the time course of recovery of 13 C label on breath over the initial 9 h of the study period (oleic acid ¼ palmitic acid > stearic acid). However, when calculated over the 24 h study period, the recovery of the label as 13 CO 2 was similar in all three trials (approximately 25 % of absorbed dose). These results support the view that chain length and degree of unsaturation may influence the gastrointestinal handling and immediate metabolic disposal of these fatty acids even when presented within an emulsion. Fatty acids: Postprandial lipid metabolism: Stable isotopes

Effect of dietary fatty acids on the postprandial fatty acid composition of triacylglycerol-rich lipoproteins in healthy male subjects

“…We therefore believe that the contamination is small. Our results of the postprandial TAG responses are in accordance with a number of studies (de Bruin et al, 1993;Muesing et al, 1995;Gatto et al, 2003), partly in line with Jones et al (1999), Sanders et al (2000), and Hunter et al (Salomaa et al, 1993;Mero et al, 1998;Roche et al, 1998;Zampelas et al, 1998). For further discussion of these responses see Tholstrup et al (2001).…”

Gender influence on plasma triacylglycerol response to meals with different monounsaturated and saturated fatty acid content

“…This could be attributed to differences in the processing of fatty acids within the gastrointestinal tract and/or effects on lipoprotein metabolism in plasma. The possible mechanisms include less efficient and slower rate of absorption and intestinal resecretion of palmitic and stearic acid, in addition to direct transport of short-and mediumchain fatty acids to the liver escaping from being transported in chylomicrons (Jones et al, 1999;van Greevenbroek et al, 2000;Mekki et al, 2002). Data from in vitro studies in Caco-2 cell line, an established model of the human enterocyte, indicate that the basolateral secretion of TAG and the TAG/ apolipoprotein B ratio are higher with oleic acid treatment compared to palmitic acid (van Greevenbroek et al, 1998).…”

The metabolism of linoleic acid in healthy subjects after intake of a single dose of 13C-linoleic acid

“…This may thus suggest that these tissues contain part of the tracer as well. Furthermore, one third of the 13 CO 2 derived from tracer oxidation may not be excreted in breath (Jones et al, 1999). Part of the tracer may be incorporated into products of the tricarboxylic acid cycle or ®xated in the bicarbonate pool (Sidossis et al, 1995;Leijssen & Elia, 1996).…”