DHA-enriched high–oleic acid canola oil improves lipid profile and lowers predicted cardiovascular disease risk in the canola oil multicenter randomized controlled trial

Background: It is well recognized that amounts of trans and saturated fats should be minimized in Western diets; however, considerable debate remains regarding optimal amounts of dietary n−9, n−6, and n−3 fatty acids. Objective: The objective was to examine the effects of varying n−9, n−6, and longer-chain n−3 fatty acid composition on markers of coronary heart disease (CHD) risk. Design: A randomized, double-blind, 5-period, crossover design was used. Each 4-wk treatment period was separated by 4-wk washout intervals. Volunteers with abdominal obesity consumed each of 5 identical weight-maintaining, fixed-composition diets with one of the following treatment oils (60 g/3000 kcal) in beverages: 1) conventional canola oil (Canola; n−9 rich), 2) high–oleic acid canola oil with docosahexaenoic acid (CanolaDHA; n−9 and n−3 rich), 3) a blend of corn and safflower oil (25:75) (CornSaff; n−6 rich), 4) a blend of flax and safflower oils (60:40) (FlaxSaff; n−6 and short-chain n−3 rich), or 5) high–oleic acid canola oil (CanolaOleic; highest in n−9). Results: One hundred thirty individuals completed the trial. At endpoint, total cholesterol (TC) was lowest after the FlaxSaff phase (P < 0.05 compared with Canola and CanolaDHA) and highest after the CanolaDHA phase (P < 0.05 compared with CornSaff, FlaxSaff, and CanolaOleic). Low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were highest, and triglycerides were lowest, after CanolaDHA (P < 0.05 compared with the other diets). All diets decreased TC and LDL cholesterol from baseline to treatment endpoint (P < 0.05). CanolaDHA was the only diet that increased HDL cholesterol from baseline (3.5 ± 1.8%; P < 0.05) and produced the greatest reduction in triglycerides (−20.7 ± 3.8%; P < 0.001) and in systolic blood pressure (−3.3 ± 0.8%; P < 0.001) compared with the other diets (P < 0.05). Percentage reductions in Framingham 10-y CHD risk scores (FRS) from baseline were greatest after CanolaDHA (−19.0 ± 3.1%; P < 0.001) than after other treatments (P < 0.05). Conclusion: Consumption of CanolaDHA, a novel DHA-rich canola oil, improves HDL cholesterol, triglycerides, and blood pressure, thereby reducing FRS compared with other oils varying in unsaturated fatty acid composition. This trial was registered at www.clinicaltrials.gov as {"type":"clinical-trial","attrs":{"text":"NCT01351012","term_id":"NCT01351012"}}NCT01351012.