Greater enrichment of triacylglycerol-rich lipoproteins with apolipoproteins E and C-III after meals rich in saturated fatty acids than after meals rich in unsaturated fatty acids.
BACKGROUND
Although there is considerable interest in the postprandial events involved in the absorption of dietary fats and the subsequent metabolism of diet-derived triacylglycerol-rich lipoproteins, little is known about the effects of meal fatty acids on the composition of these particles.


OBJECTIVE
We examined the effect of meal fatty acids on the lipid and apolipoprotein contents of triacylglycerol-rich lipoproteins.


METHODS
Ten normolipidemic men received in random order a mixed meal containing 50 g of a mixture of palm oil and cocoa butter [rich in saturated fatty acids (SFAs)], safflower oil [n-6 polyunsaturated fatty acids (PUFAs)], or olive oil [monounsaturated fatty acids (MUFAs)] on 3 occasions. Fasting and postprandial apolipoproteins B-48, B-100, E, C-II, and C-III and lipids (triacylglycerol and cholesterol) were measured in plasma fractions with Svedberg flotation rates (S(f)) >400, S(f) 60-400, and S(f) 20-60.


RESULTS
Calculation of the composition of the triacylglycerol-rich lipoproteins (expressed per mole of apolipoprotein B) showed notable differences in the lipid and apolipoprotein contents of the SFA-enriched particles in the S(f) > 400 and S(f) 60-400 fractions. After the SFA meal, triacylglycerol-rich lipoproteins in these fractions showed significantly greater amounts of triacylglycerol and of apolipoproteins C-II (S(f) 60-400 fraction only), C-III, and E than were found after the MUFA meal (P < 0.02) and more cholesterol, apolipoprotein C-III (S(f) > 400 fraction only), and apolipoprotein E than after the PUFA meal (P < 0.02).


CONCLUSIONS
Differences in the composition of S(f) > 400 and S(f) 60-400 triacylglycerol-rich lipoproteins formed after saturated compared with unsaturated fatty acid-rich meals may explain differences in the metabolic handling of dietary fats.
Jackson
Kim G
KG
Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences, The University of Reading, Reading, UK. k.g.jackson@reading.ac.uk
Wolstencroft
Emma J
EJ
Bateman
Paul A
PA
Yaqoob
Parveen
P
Williams
Christine M
CM
D001056:Apolipoproteins C / Q000378:metabolism*; D001057:Apolipoproteins E / Q000378:metabolism*; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000378:metabolism*; D005227:Fatty Acids / Q000008:administration & dosage / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000378:metabolism*; D006801:Humans; D008074:Lipoproteins / Q000008:administration & dosage / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000008:administration & dosage / Q000494:pharmacology*
D001056:Apolipoproteins C; D001057:Apolipoproteins E; D004041:Dietary Fats; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008074:Lipoproteins; D014280:Triglycerides