Trans monounsaturated fatty acids and saturated fatty acids have similar effects on postprandial flow-mediated vasodilation

Abstract

Objective: Several studies suggest that a fatty meal impairs flow-mediated vasodilation (FMD), a measure of endothelial function. We tested whether the impairment was greater for trans fats than for saturated fats. We did this because we previously showed that replacement of saturated fats by trans fats in a controlled diet decreased FMD after 4 weeks. Design: We fed 21 healthy men two different test meals with 0.9 -1.0 g fat=kg body weight in random order: one rich in saturated fatty acids (Sat), mainly from palm kernel fat, and one rich in trans fatty acids (Trans) from partially hydrogenated soy bean oil. The study was performed in our metabolic ward. We had complete data for both diets of 21 men. Results: FMD increased from a fasting value of 2.3 AE 2.0% of the baseline diameter to 3.0 AE 1.7% after the Sat test meal (95% CI for change 7 0.33, 1.70) and from 2.7 AE 2.3 to 3.1 AE 2.0% after the Trans test meal (95% CI for change 7 0.57, 1.29). The increase after the Sat meal was 0.22 ( 7 1.18 -1.61) FMD% higher than after the Trans meal. Serum triacylglycerols increased by 0.46 AE 0.36 mmol=l after the Sat test meal and by 0.68 AE 0.59 mmol=l after the Trans test meal; a difference of 0.23 (0.07, 0.39) mmol=l. Serum HDL-cholesterol was hardly affected by the test meals. The activity of serum paraoxonase, an esterase bound to HDL, increased slightly after the two test meals but the difference between meals was not significant. Conclusion: FMD was not impaired and not different after test meals with saturated or trans fatty acids. Thus, differences in long-term effects of these fats are not caused by differences in acute effects on the vascular wall.

Health effects of trans-fatty acids: experimental and observational evidence

“…In generally healthy men, five weeks of TFA consumption (8%E) increased levels of E-selectin, a circulating biomarker of endothelial dysfunction, by 10, 14, 6 and 6% compared with equivalent calories from carbohydrate, MUFA, stearic acid or shorter-chain (12:0-16:0) SFA, respectively (Baer et al, 2004). Consumption of a single meal enriched with TFA or SFA showed similar acute adverse effects on postprandial flow-mediated vasodilatation of the brachial artery, a functional measure of endothelial health (de Roos et al, 2002). A longer duration (4 weeks) of TFA intake (9.2%E) significantly lowered HDL-C (21% reduction) and impaired brachial artery flow-mediated vasodilatation (29% reduction) compared with equivalent calories from SFA (de Roos et al, 2001).…”

Confiabilidade da medida da dilatação fluxo-mediada da artéria braquial pela ultra-sonografia

“…Variation coefficients (VC) reported in literature, were extremely inconsistent, with a mean of 1.8% for same and separate day measurements 11 and values as high as 84% between the separate day measurements 12 . It should be noted that different measurement techniques were used in the available studies.…”

“…For the most part, the studies available in literature obtain the measurements from VHS tape recordings 10,12,19,23 or semiautomatic measurements using computer programs developed for this purpose 17,26 . These procedures reduce an important source of measurement error, which is the experience of the ultrasonographer 9 , making comparison with the results of the present study more difficult.…”

Calidad de grasa, arterioesclerosis y enfermedad coronaria: efectos de los ácidos grasos saturados y ácidos grasos trans

“…Roos et al 48 observaron que el consumo de una comida enriquecida con AGT o AGS tuvieron efectos adversos similares sobre vasodilatación posprandial mediado por fl ujo (VMF) de la arteria braquial.…”