Postprandial Fatty Acid Profile, but Not Cardiometabolic Risk Markers, Is Modulated by Dairy Fat Manipulation in Adults with Moderate Cardiovascular Disease Risk: The Randomized Controlled REplacement of SaturatEd fat in dairy on Total cholesterol (RESET) Study

Abstract

Background Chronic consumption of dairy products with an SFA-reduced, MUFA-enriched content was shown to impact favorably on brachial artery flow-mediated dilatation (FMD). However, their acute effect on postprandial cardiometabolic risk biomarkers requires investigation. Objective The effects of sequential high-fat mixed meals rich in fatty acid (FA)–modified or conventional (control) dairy products on postprandial FMD (primary outcome) and systemic cardiometabolic biomarkers in adults with moderate cardiovascular risk (≥50% above the population mean) were compared. Methods In a randomized crossover trial, 52 participants [mean ± SEM age: 53 ± 2 y; BMI (kg/m2) 25.9 ± 0.5] consumed a high-dairy-fat breakfast (0 min; ∼50 g total fat: modified: 25 g SFAs, 20 g MUFAs; control: 32 g SFAs, 12 g MUFAs) and lunch (330 min; ∼30 g total fat; modified: 15 g SFAs, 12 g MUFAs; control: 19 g SFAs, 7 g MUFAs). Blood samples were obtained before and until 480 min after breakfast, with FMD assessed at 0, 180, 300, and 420 min. Data were analyzed by linear mixed models. Results Postprandial changes in cardiometabolic biomarkers were comparable between the different dairy meals, with the exception of a tendency for a 4% higher AUC for the %FMD response following the modified-dairy-fat meals (P = 0.075). Plasma total lipid FA analysis revealed that incremental AUC responses were 53% lower for total SFAs, 214% and 258% higher for total cis-MUFAs (predominantly cis-9 18:1), and trans-18:1, respectively, following the modified relative to the control dairy meals (all P < 0.0001). Conclusions In adults at moderate cardiovascular risk, acute consumption of sequential high-fat meals containing FA-modified dairy products had little impact on postprandial endothelial function or systemic cardiometabolic biomarkers, but a differential effect on the plasma total lipid FA profile, relative to conventional dairy fat meals. This trial was registered at clinicaltrials.gov as NCT02089035.

Effect of fat-reformulated dairy food consumption on postprandial flow-mediated dilatation and cardiometabolic risk biomarkers compared with conventional dairy: a randomized controlled trial

“…Elevated postprandial triacylglycerol (TG) concentration (an independent CVD risk factor) after high-fat meal consumption can potentiate inflammatory events and induce transient endothelial dysfunction, which is reflective of a vascular phenotype prone to atherogenesis ( 7 ). We observed a tendency for a higher AUC for the %FMD response following acute exposure to sequential FA-modified dairy fat–rich meals, relative to conventional dairy ( 8 ). However, the FA composition of the background diet can also influence postprandial cardiometabolic responses and may be of greater importance to long-term health than isolated (acute) dietary FA exposures ( 9 ).…”

“…A minimization technique that stratified by age (25.0–40.0 or 40.1–55.1 or 55.2–70.0 y), sex (male or female), BMI (19.0–26.9 or 27.0–32.0 kg/m 2 ), and fasting serum TC (≤5.9 or ≥6.0–8.0 mmol/L) was used by a single researcher (OM) to randomly allocate participants to their first treatment period, as previously described ( 5 , 15 ). A 480-min postprandial study visit was performed at the beginning [preintervention: week 0, week 20; acute study results are presented in our earlier publication ( 8 )] and end (postintervention: week 12, week 32) of each dietary period. This enabled us to examine the effect of longer-term dairy FA manipulation on postprandial endothelial function and systemic cardiometabolic responses to a sequential 2-meal dairy fat challenge (see Figure 1 ).…”

“…The sequential 2-meal dairy fat challenge was conducted using dairy products identical to those assigned in the FA-modified and conventional (control) dietary intervention periods, as described previously ( 8 ). The energy and nutrient compositions of the sequential meals (breakfast and lunch) and test meal ingredients are outlined in Table 1 .…”

“… 1 Values are total energy and macronutrient quantities of each test meal according to modified and control diet. Adapted from reference ( 8 ). FA, fatty acid; TFA, trans fatty acid.…”

“…Ultrasound assessment of FMD of the brachial artery was conducted on the uncannulated arm using a CX50 CompactXtreme Ultrasound System (Philips HealthCare, UK), in accordance with internationally accepted guidelines ( 21 ) and as described in detail elsewhere ( 5 , 8 ). In brief, a single trained researcher performed all measurements for a given participant in a quiet, temperature-controlled clinical room (22° ± 1°C), which was darkened for endothelial function assessments.…”