Michael L. Kagan
Aharon Levyb and Alicia Leikin-Frenkelc
Long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) exert health bene
ﬁ ts which are depen- dent upon their incorporation into blood, cells and tissues. Plasma and tissue deposition of LC n-3 PUFA from oils extracted from the micro-algae Nannochloropsis oculata and from krill were compared in rats. The algal oil provides eicosapentaenoic acid (EPA) partly conjugated (15%) to phospholipids and glyco- lipids but no docosahexaenoic acid (DHA), whereas krill oil provides both EPA and DHA conjugated in part (40%) to phospholipids. Rats fed a standard diet received either krill oil or polar-lipid rich algal oil by gavage daily for 7 days (5 ml oil per kg body weight each day). Fatty acid concentrations were analyzed in plasma, brain and liver, and two adipose depots since these represent transport, functional and storage pools of fatty acids, respectively. When measuring total LC n-3 PUFA (sum of EPA, docosapentaenoic acid (DPA) and DHA), there was no statistically signi
ﬁ cant di ﬀ
erence between the algal oil and krill oil for plasma, brain, liver and gonadal adipose tissue. Concentrations of LC n-3 PUFA were higher in the retro- peritoneal adipose tissue from the algal oil group. Tissue uptake of LC n-3 PUFA from an algal oil contain- ing 15% polar lipids (glycolipids and phospholipids) was found to be equivalent to krill oil containing 40% phospholipids. This may be due to glycolipids forming smaller micelles during ingestive hydrolysis than phospholipids. Ingestion of fatty acids with glycolipids may improve bioavailability, but this needs to be further explored.