Acute Effect of Dietary Fats on Postprandial Vascular Function in Healthy Individuals: A Randomized, Controlled Trial

Abstract

IntroductionResearch has shown an association between fat consumption and vascular function. Recent evidence suggests that a high saturated fat meal may impair vasodilatory mechanisms post‐ingestion, while other types of dietary fats, depending on chain length, saturation and omega 3:6 ratio may potentially improve vascular function. There have been no head to head comparisons of postprandial effects on commonly consumed sources of dietary cooking oils on vascular function.ObjectivesThe purpose of the study was to assess the effects of 5 different dietary fat sources of varied fatty acid profiles (coconut oil, canola oil, grapeseed oil, Salba‐chia seed oil, and butter) on indices of vascular function and the glycemic response in a healthy adult population.MethodsThe study recruited 15 healthy individuals (10F:5M; age 29±8; SBP/DBP: 121±10/82±4 mmHg) in a double blind, randomized, crossover, controlled design. Participants visited the clinic at St. Michael's Hospital 5 different times following an overnight fast. At each visit, following collection of anthropometric data and baseline outcome measures, 1 of 5 500ml study shakes were consumed containing 50g of fat (from either: coconut oil, canola oil, grapeseed oil, chia oil or butter) and 50g of available carbohydrate. Over a 3 hour period following intake of study interventions, vascular measures were obtained at hourly intervals and fingerprick blood samples at 0,15, 30, 45, 60, 90 and 180min. The primary outcome was a change in pulse wave reflection (augmentation index‐AIx (%)). Secondary outcome measures included postprandial blood glucose area under the curve (AUC), peripheral and central systolic and diastolic blood pressures.ResultsIntervention high in omega‐3 fatty acids (Salba‐chia seed oil) produced a reduction in pulse wave reflection relative to the butter control (1h AIx:−5.9±6%, p=0.041; 3h AIx: −3.8±7% p=0.048). All study beverages resulted in a similar acute blood pressure response (−1.2±3mmHg, p=0.25), independently of the type of oil ingested. No significant differences in blood glucose AUC (p=0.69) to the 5 fat‐rich glucose beverages were observed.ConclusionsNo difference was found in the acute effect of the ingestion of different vegetable oils on hemodynamic indices. All vegetable oils produced a postprandial decrease in hemodynamic indices in healthy participants.Support or Funding InformationInternal