Palmitic Acid-Rich Oils With And Without Interesterification Lower Postprandial Lipemia And Increase Atherogenic Lipoproteins Compared With A Mufa-Rich Oil: A Randomized Controlled Trial

Background: Interesterified (IE) fats are widely used in place of trans fats; however, little is known about their metabolism.Objectives: To test the impact of a commonly consumed compared with a non-IE equivalent fat on in vivo postprandial and in vitro lipid metabolism, compared with a reference oil [rapeseed oil (RO)].Methods: A double-blinded. 3-phase crossover, randomized controlled trial was performed in healthy adults (n = 20) aged 45-75 y. Postprandial plasma triacylglycerol and lipoprotein responses (including stable isotope tracing) to a test meal (50 g fat) were evaluated over 8 h. The test fats were IE 80:20 palm stearin/palm kernel fat, an identical non-IE fat, and RO (control). In vitro, mechanisms of digestion were explored using a dynamic gastric model (DGM).Results: Plasma triacylglycerol 8-h incremental area under the curves were lower following non-IE compared with RO [-1.7 mmol/L.h (95% CI: -3.3. -0.0)], but there were no differences between IE and RO or IE and non-IE. LDL particles were smaller following IE and non-IE compared with RO (P = 0.005). Extra extra large. extra large, and large VLDL particle concentrations were higher following IE and non-IE compared with RO at 6-8 h (P < 0.05). No differences in the appearance of [C-13]palmitic acid in plasma triacylglycerol were observed between IE and nonIE fats. DGM revealed differences in phase separation of the IE and non-IE meals and delayed release of SFAs compared with RO.Conclusions: Interesterification did not modify fat digestion. postprandial lipemia, or lipid metabolism measured by stable isotope and DGM analysis. Despite the lower lipemia following the SFA-rich fats, increased proatherogenic large triacylglycerol-rich lipoprotein remnant and small LDL particles following the SFA-rich fats relative to RO adds a new postprandial dimension to the mechanistic evidence linking SFAs to cardiovascular disease risk.