Two Blends of Refined Rice Bran, Flaxseed, and Sesame Seed Oils Affect the Blood Lipid Profile of Chinese Adults with Borderline Hypercholesterolemia to a Similar Extent as Refined Olive Oil

Abstract

Individual vegetable oils have a characteristic fatty acids (FA) composition and unique phytonutrient profiles, enabling formulation of oil blends that may have health-promoting effects. The primary objective of this study was to investigate effects of 2 oil blends made with refined rice bran, flaxseed, and sesame oils, with distinct monounsaturated to saturated FA, polyunsaturated to saturated FA, and omega-3 (n-3) to omega-6 FA ratios and different phytonutrient concentrations on blood lipid profile, compared with refined olive oil as a control. The secondary outcomes were other markers of cardiometabolic health. A parallel-design, randomized controlled trial compared consumption of 30g of allocated intervention oil per day for a period of 8 wk. The study recruited 143 borderline hypercholesterolemic (LDL cholesterol: 3.06-4.51mmol/L) Chinese volunteers between 50 and 70 y old and with a BMI (kg/m2) ≤27.5. All outcomes were measured every 2 wk, and the time × treatment interactions and the main effects of treatment and time were analyzed using an intention-to-treat approach. Compared with baseline (week 0), there were significant reductions during the post-intervention time points in serum total cholesterol (-3.47%; P<0.0001), LDL cholesterol (-4.16%; P<0.0001), triglycerides (-10.3%; P<0.0001), apoB (-3.93%; P<0.0001), total to HDL-cholesterol (-3.44%; P<0.0001) and apoB to apoA1 (-3.99%; P<0.0001) ratios, systolic and diastolic blood pressures (-3.32% and -3.16%, respectively; both P<0.0001), and serum glucose (-1.51%; P<0.05) and a small but significant increase in body weight (+0.7%; P<0.001) for all 3 intervention oils but no effects of intervention on HDL-cholesterol or apoA1 concentration. No significant effects of treatment or time × treatment interactions were found. Using blended vegetable oils that are extensively consumed in Asia, this study found that specific oil blends can improve blood lipid profile and other cardiometabolic parameters, to a similar extent as refined olive oil, in Chinese adults with borderline hypercholesterolemia. This trial is registered at www.clinicaltrials.gov as NCT03964857.