Lipid-lowering and anti-inflammatory effects of omega 3 ethyl esters and krill oil: a randomized, cross-over, clinical trial
What this study found
Both supplements lowered triglycerides, and krill oil produced lipid-lowering effects comparable to the higher-dose omega-3 ethyl esters. In the omega-3 ethyl ester arm, triglycerides fell by -72.8 mg/dl (p=0.001) and hs-CRP by -0.14 mg/l (p=0.030); in the krill oil arm, triglycerides fell by -55.7 mg/dl (p=0.003), HDL-C rose by +4.5 mg/dl (p=0.039), non-HDL-C fell by -8.1 mg/dl (p=0.009), and hs-CRP fell by -0.35 mg/l (p<0.001). Overall, krill oil appeared more effective than omega-3 ethyl esters for raising HDL-C and reducing inflammation while preserving triglyceride-lowering efficacy.
- Study & population
- Randomized, crossover clinical trial in non-smoking, mildly overweight adults with hypertriglyceridemia who were not taking lipid-lowering drugs and were enrolled for primary prevention.
- Intervention
- Oral omega-3 ethyl ester PUFAs 1000 mg twice daily versus oral krill oil 500 mg twice daily, given as pills for 4 weeks per treatment period in a randomized crossover design, with a 4-week washout before crossover.
- Key limitation
- The trial was small, with only 25 participants per active arm, and each treatment period lasted only 4 weeks.
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Open PDFOriginal abstract
Introduction Polyunsaturated fatty acids (PUFAs) derived from different sources could have different lipid-lowering effects in humans. The main aim of our study was to compare the short-term triglyceride-lowering efficacy of krill oil and purified omega 3 ethyl ester PUFAs in mildly overweight hypertriglyceridemic subjects. Material and methods This double-blind, randomized clinical trial was carried out in 25 moderately hypertriglyceridemic subjects (TG = 150–500 mg/dl). After a 4-week run-in, participants were allocated to treatment with similar pills containing omega 3 ethyl ester PUFAs 1000 mg twice a day vs. krill oil 500 mg twice a day. After 4 weeks of treatment, participants were asked to observe a 4-week wash-out period, and they were then assigned to the alternative treatment for a further period of 4 weeks. Results Although both PUFA sources were able to improve TG plasma levels, esterified omega 3 PUFAs were more efficacious than krill oil (p < 0.05). Nonetheless, only krill oil treatment was able to significantly improve high-density lipoprotein cholesterol and apolipoprotein AI levels, compared to both baseline (p < 0.05) and end of treatment with esterified omega 3 PUFAs (p < 0.05) values. Both treatments were able to significantly reduce high-sensitivity C-reactive protein (hs-CRP) levels from the baseline (p < 0.05), but krill oil improved it more efficaciously than esterified omega 3 PUFAs (p < 0.05). Conclusions Krill oil has lipid-lowering effects comparable with those obtained through a 4-fold higher dose of purified omega 3 ethyl ester PUFAs in mildly overweight hypertriglyceridemic subjects, while more efficaciously reducing hs-CRP.