Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil

Abstract

Background: Due to structural differences, bioavailability of krill oil, a phospholipid based oil, could be higher than fish oil, a triglyceride-based oil, conferring properties that render it more effective than fish oil in increasing omega-3 index and thereby, reducing cardiovascular disease (CVD) risk.

Objective: The objective was to assess the effects of krill oil compared with fish oil or a placebo control on plasma and red blood cell (RBC) fatty acid profile in healthy volunteers.

Participants and methods: Twenty four healthy volunteers were recruited for a double blinded, randomized, placebo-controlled, crossover trial. The study consisted of three treatment phases including krill or fish oil each providing 600 mg of n-3 polyunsaturated fatty acids (PUFA) or placebo control, corn oil in capsule form. Each treatment lasted 4 wk and was separated by 8 wk washout phases.

Results: Krill oil consumption increased plasma (p = 0.0043) and RBC (p = 0.0011) n-3 PUFA concentrations, including EPA and DHA, and reduced n-6:n-3 PUFA ratios (plasma: p = 0.0043, RBC: p = 0.0143) compared with fish oil consumption. Sum of EPA and DHA concentrations in RBC, the omega-3 index, was increased following krill oil supplementation compared with fish oil (p = 0.0143) and control (p < 0.0001). Serum triglycerides and HDL cholesterol concentrations did not change with any of the treatments. However, total and LDL cholesterol concentrations were increased following krill (TC: p = 0.0067, LDL: p = 0.0143) and fish oil supplementation (TC: p = 0.0028, LDL: p = 0.0143) compared with control.

Conclusions: Consumption of krill oil was well tolerated with no adverse events. Results indicate that krill oil could be more effective than fish oil in increasing n-3 PUFA, reducing n-6:n-3 PUFA ratio, and improving the omega-3 index.

Trial registration: ClinicalTrials.gov, NCT01323036.

Figure 1

Schematic representation of the experimental protocol. B - 12 h fasted blood collection; AN - Anthropometric measurements; IE - Inclusion and Exclusion criteria; PE - Physician examination; AE - Adverse events; CD - Capsule dispensation (KO or FO or corn oil capsules); CR - Left over capsules return; Q - Questionnaires (Fish and sea food consumption, concomitant medications); GI - Gastro intestinal questionnaires.