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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 n29, n26, and n 23 fatty acids. Objective: The objective was to examine the effects of varying n29, n26, and longer-chain n 23 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; n29 rich), 2) high-oleic acid canola oil with docosahexaenoic acid (CanolaDHA; n29 and n23 rich), 3) a blend of corn and safflower oil (25:75) (CornSaff; n26 rich), 4) a blend of flax and safflower oils (60:40) (FlaxSaff; n26 and short-chain n23 rich), or 5) high-oleic acid canola oil (CanolaOleic; highest in n29). Results: One hundred thirty individuals completed the trial. At end-point, 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. [ABSTRACT FROM AUTHOR]

Existing evidence on the influence of genetic architecture on serum cholesterol responsiveness to dietary interventions focuses on individual single nucleotide polymorphisms and single nutrients. We associated the combination of ABCG5 rs6720173-C, CYP7A1 rs3808607-TT, and DHCR7 rs760241-GG genotypes with lower low-density lipoprotein cholesterol concentrations relative to the combination of rs6720173-GG, rs3808607-G, and rs760241-A genotypes (-0.37 ± 0.12 (n = 9) vs. +0.38 ± 0.14 mmol/L (n = 7), p = 0.0016) following a blended dairy (3 servings/day for 4 weeks) intervention.