Acute Effects of a High-Fat Meal Enriched with Pomegranate Seed Oil on Postprandial Lipemia and Endothelial Function in Postmenopausal Women: a Randomized Controlled Crossover Trial

TL;DR

A meal enriched with pomegranate seed oil reduced post-meal fat levels and improved blood vessel function in postmenopausal women, suggesting heart benefits.

Contribution

This study is the first to show that pomegranate seed oil acutely improves endothelial function and reduces postprandial lipemia in postmenopausal women.

Findings

A PSO-rich meal significantly reduced postprandial triacylglycerol (TAG) levels compared to a control meal.

The meal improved endothelium-dependent vasodilation and lowered systolic blood pressure.

Plasma nitrite concentrations increased, and adhesion molecule responses decreased after the PSO meal.

Abstract

Postprandial elevation of triacylglycerol (TAG) is associated with endothelial dysfunction and represents an important independent cardiovascular disease (CVD) risk factor in women. Although daily intakes of pomegranate seed oil (PSO, 80% conjugated α-linolenic acids) reduce fasting lipids, little is known about the acute effects on postprandial CVD risk markers.

This study compared the impact of a PSO-rich meal with those of a control meal on postprandial TAG (primary outcome measure), lipids, glucose, insulin, microvascular function, and cell adhesion molecule responses in postmenopausal women.

In a single-blind, randomized controlled postprandial crossover study, 16 postmenopausal women aged ≤65 y were assigned to consume either a PSO-rich or a control meal on 2 separate occasions, 4 to 6 wk apart. A high-fat mixed meal (50 g fat) was provided at breakfast (0 min), and blood samples collected until 480 min postprandially to assess CVD risk markers. Specific time points were selected for blood pressure (BP) (0, 120, 240, 360 and 480 min) and microvascular reactivity (0, 180, 300, and 420 min). Postprandial data were analyzed using linear mixed models.

Compared with the control meal, the PSO-rich meal significantly reduced the postprandial TAG response but glucose, insulin, apolipoprotein B, and non-esterified fatty acid responses were similar. The AUC and incremental AUC (iAUC) for the postprandial acetylcholine (endothelium-dependent vasodilation) induced reactivity response were greater (P ≤ 0.04), and systolic BP lower after the PSO-rich meal than the control meal. Additionally, the iAUC for the pulse wave velocity and AUC/iAUC for the soluble intercellular adhesion molecule-1 responses were lower, whereas plasma nitrite concentrations were higher after the PSO-rich than control meal (P ≤ 0.037).

A PSO-rich meal significantly reduced the postprandial TAG response and enhanced endothelial function compared with a control meal, suggesting a potential cardioprotective effect in postmenopausal women.

This study was registered at clinicaltrials.gov as NCT06042673 (https://clinicaltrials.gov/study/NCT06042673).

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