HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 296/1/E64    most recent 90730.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Hodson, L. Articles by Fielding, B. A. Search for Related Content PubMed PubMed Citation Articles by Hodson, L. Articles by Fielding, B. A.

Differences in partitioning of meal fatty acids into blood lipid fractions: a comparison of linoleate, oleate, and palmitate

¹Oxford Centre for Diabetes, Endocrinology, and Metabolism and ²National Institute of Health and Research, Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, United Kingdom

Submitted 1 September 2008 ; accepted in final form 10 October 2008

There has been much interest in the health effects of dietary fat, but few studies have comprehensively compared the acute metabolic fate of specific fatty acids in vivo. We hypothesized that different classes of fatty acids would be variably partitioned in metabolic pathways and that this would become evident over 24 h. We traced the fate of fatty acids using equal amounts of [U-¹³C]linoleate, [U-¹³C]oleate, and [U-¹³C]palmitate given in a test breakfast meal in 12 healthy subjects. There was a tendency for differences in the concentrations of the tracers in plasma chylomicron-triacylglycerol (TG) (oleate > palmitate > linoleate). This pattern remained in plasma nonesterified fatty acid (NEFA) and very low-density lipoprotein (VLDL)-TG (P 0.01 and P 0.02 for [U-¹³C]oleate vs. both [U-¹³C]palmitate and [U-¹³C]linoleate for NEFA and VLDL-TG, respectively). There was significantly more [U-¹³C]linoleate than the other two tracers in plasma cholesteryl ester and phospholipid (PL). Using the values for isotopic enrichment in the different lipid fractions compared with the test meal, we calculated the contribution of meal fatty acids to the respective fractions. At 24 h, 10% of plasma PL-linoleate originated from the breakfast test meal. This was significantly greater than for oleate and palmitate (both 3 ± 0.3%; P < 0.05). This pattern was also true for erythrocyte PL fatty acids. The marked rapid incorporation of linoleate from a single meal into blood PL fractions may have functional consequences such as maintenance of membrane fluidity and may explain why linoleate is a useful biomarker of dietary intake.

chylomicrons; nonesterified fatty acids; very low-density lipoprotein; stable isotopes; postprandial metabolism