Supplementation with saury oil, a fish oil high in omega-11 monounsaturated fatty acids, improves plasma lipids in healthy subjects.

Background: Fish oil enriched in omega-11 long-chain monounsaturated fatty acids (LCMUFAs; C20:1 and C22:1 isomers combined) have shown lipid-lowering and atheroprotective effects in animal models.

Objective: To perform a first-in-human trial of LCMUFA-rich saury fish oil supplementation to test its safety and possible effect on plasma lipids.

Methods: A double-blind, randomized, crossover clinical trial was carried out in 30 healthy normolipidemic adults (BMI <25 kg/m; mean TG, 84 mg/dL). Treatment periods of 8 weeks were separated by an 8-week washout period. Subjects were randomized to receive either 12 g of saury oil (3.5 g of LCMUFA and 3.4 g of omega-3 FAs) or identical capsules with control oil (a mixture of sardine and olive oil; 4.9 g of shorter-chain MUFA oleate and 3 g of omega-3 FAs).

Results: Saury oil supplementation was safe and resulted in LDL particle counts 12% lower than control oil (P < .001). Saury oil also had a minor effect on increasing HDL particle size (9.8 nm vs 9.7 nm; P < .05) based on a linear mixed effect model. In contrast, control oil, but not saury oil, increased LDL-C by 7.5% compared with baseline (P < .05). Saury oil had similar effects compared with control oil on lowering plasma TG levels, VLDL, and TG-rich lipoprotein particle counts (by ∼16%, 25%, and 35%, respectively; P < .05), and increasing HDL-C and cholesterol efflux capacity (by ∼6% and 8%, respectively; P < .05) compared with baseline.

Conclusion: Saury oil supplementation is well tolerated and has beneficial effects on several cardiovascular parameters, such as LDL particle counts, HDL particle size, and plasma TG levels.