Holli Ryan RD, LD/N
Krill oil and fish oil are both healthful, omega-3 fatty acid containing marine oils derived from ocean-dwelling animals. Krill (Euphausia superba) are shrimp-like crustaceans that have gained in popularity as a means of omega-3 supplementation in recent years. Omega-3 containing fish oils are sourced from a variety of fatty fish such as anchovy, pollock, cod, or salmon. Let’s compare and contrast the two sources and determine if one is better than the other.
Pros of Fish Oil
- Cost and Availability – fish oil is generally more widely available and cost effective.
- Amount of Omega-3 Fatty Acids – fish oil offers more EPA and DHA compared to the same amount of krill oil. While some research suggests that the triglyceride (TAG) form may be better absorbed, the ethyl ester (EE) form offers the best value at the highest concentration of omega-3 fatty acids.
- More, long-term scientific studies (especially the EE form) – Fish oil even has pharmaceutical-funded clinical trials behind it that proved its efficacy and as a result, is available as a prescription medication called Lovaza.
Pros of Krill Oil
- Unique Chemical Structure – the omega-3 fatty acids are primarily bound to phospholipid
- Absorption – phospholipids may improve absorption
- Additional Benefit – Studies show that the fatty acids found in krill oil are particularly effective for joint health.
- Antioxidant – contains astaxanthin (reddish pigment) which may benefit cognitive health, skin health, and more.
Why supplement with omega-3 fatty acids at all? Many typical modern diets do not provide enough omega-3 fatty acids. Whether you choose fish, krill, or both as your source of omega-3, both will provide the benefits listed below if taken in the right amounts. Life Extension recommends 1400 mg of EPA and 1000 mg of DHA daily to support optimal health.
Related Article: Dangers of an Omega-6 to Omega-3 Imbalance
Benefits of Omega-3 Fatty Acids: EPA & DHA
- The omega-3 fatty acids EPA and DHA work together to promote a healthy inflammatory response to support whole-body health.1
- Eicosapentaenoic acid (EPA) is especially important for healthy inflammatory pathways and for cardiovascular health.2-4
- Docosahexaenoic acid (DHA) is the predominant fatty acid in retinal, neuronal and brain cell membranes; it is especially important for visual and neurological (brain and nervous system) health.5-7
- Together, EPA and DHA support cardiovascular health, heart function and normal heart rhythm.8,9
- Omega-3 ethyl esters (EE) have been shown to lower triglyceride levels.10-12
- Omega-3 fatty acids are important for healthy brain function and cognitive development throughout the lifespan.13-15
Benefits of Krill Oil
- Krill is a natural source of the antioxidant carotenoid astaxanthin and EPA and DHA that are mostly bound to phospholipids (like phosphatidylcholine).
- Approx. 60-70% of the omega-3 fatty acids in krill oil are bound to phospholipids.16
- Phospholipid-bound omega-3s may be more efficiently absorbed than unbound.16
- Like fish oil, krill offers benefits for cardiovascular (possibly to a greater extent than fish) and brain health.17-19
- Krill oil may provide more targeted support for the nervous system because the omega-3s it provides are more rapidly taken up into red blood cells (RBCs) which may then be quickly incorporated into brain cells.20
- Krill has been shown to benefit joint health.21
The Bottom Line: Krill or Fish Oil?
Combining traditional fish oil with krill oil may offer additional health benefits beyond supplementing with either alone. The two sources complement each other and offer a person more comprehensive health benefits.22 The ideal supplementation strategy would be to combine the various fish oil forms (EE and TAG) along with krill oil (phospholipid). This combination allows one to receive optimal amounts of EPA and DHA while taking advantage of the full spectrum of benefits from these three unique omega-3 forms, in addition to the antioxidant astaxanthin from krill. More studies are needed to confirm the absorption characteristics of phospholipid bound omega-3 in krill and how this relates to increasing EPA and DHA blood levels. Lab testing is a good way to determine if the type/form you are taking is raising your blood levels.
- Calder PC. Omega-3 fatty acids and inflammatory processes: from molecules to man. Biochemical Society transactions. 2017;45(5):1105-1115.
- Ohnishi H, Saito Y. Eicosapentaenoic acid (EPA) reduces cardiovascular events: relationship with the EPA/arachidonic acid ratio. J Atheroscler Thromb. 2013;20(12):861-877.
- Bhatt DL, Steg PG, Miller M, et al. Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia. N Engl J Med. 2019;380(1):11-22.
- Miller M, Ballantyne CM, Bays HE, et al. Effects of Icosapent Ethyl (Eicosapentaenoic Acid Ethyl Ester) on Atherogenic Lipid/Lipoprotein, Apolipoprotein, and Inflammatory Parameters in Patients With Elevated High-Sensitivity C-Reactive Protein (from the ANCHOR Study). The American journal of cardiology. 2019;124(5):696-701.
- Singh M. Essential fatty acids, DHA and human brain. Indian journal of pediatrics. 2005;72(3):239-242.
- Sun GY, Simonyi A, Fritsche KL, et al. Docosahexaenoic acid (DHA): An essential nutrient and a nutraceutical for brain health and diseases. Prostaglandins, leukotrienes, and essential fatty acids. 2018;136:3-13.
- Walczewska A, Stepien T, Bewicz-Binkowska D, Zgorzynska E. [The role of docosahexaenoic acid in neuronal function]. Postepy higieny i medycyny doswiadczalnej (Online). 2011;65:314-327.
- Harris WS, Zotor FB. n-3 Fatty acids and risk for fatal coronary disease. The Proceedings of the Nutrition Society. 2019;[epub ahead of print]:1-6.
- Sokola-Wysoczanska E, Wysoczanski T, Wagner J, et al. Polyunsaturated Fatty Acids and Their Potential Therapeutic Role in Cardiovascular System Disorders-A Review. Nutrients. 2018;10(10).
- Song J, Hu M, Li C, et al. Dose-dependent effects of fish oil on cardio-metabolic biomarkers in healthy middle-aged and elderly Chinese people: a double-blind randomized controlled trial. Food & function. 2018;9(6):3235-3243.
- Zulyniak MA, Roke K, Gerling C, Logan SL, Spriet LL, Mutch DM. Fish oil regulates blood fatty acid composition and oxylipin levels in healthy humans: A comparison of young and older men. Molecular nutrition & food research. 2016;60(3):631-641.
- Shearer GC, Savinova OV, Harris WS. Fish oil — how does it reduce plasma triglycerides? Biochimica et biophysica acta. 2012;1821(5):843-851.
- Zhang Y, Chen J, Qiu J, Li Y, Wang J, Jiao J. Intakes of fish and polyunsaturated fatty acids and mild-to-severe cognitive impairment risks: a dose-response meta-analysis of 21 cohort studies. The American journal of clinical nutrition. 2016;103(2):330-340.
- Amen DG, Harris WS, Kidd PM, Meysami S, Raji CA. Quantitative Erythrocyte Omega-3 EPA Plus DHA Levels are Related to Higher Regional Cerebral Blood Flow on Brain SPECT. Journal of Alzheimer’s disease : JAD. 2017;58(4):1189-1199.
- Berger ME, Smesny S, Kim SW, et al. Omega-6 to omega-3 polyunsaturated fatty acid ratio and subsequent mood disorders in young people with at-risk mental states: a 7-year longitudinal study. Translational psychiatry. 2017;7(8):e1220.
- Ramprasath VR, Eyal I, Zchut S, Shafat I, Jones PJ. Supplementation of krill oil with high phospholipid content increases sum of EPA and DHA in erythrocytes compared with low phospholipid krill oil. Lipids Health Dis. 2015;14:142.
- Ursoniu S, Sahebkar A, Serban MC, et al. Lipid-modifying effects of krill oil in humans: systematic review and meta-analysis of randomized controlled trials. Nutrition reviews. 2017;75(5):361-373.
- Konagai C, Yanagimoto K, Hayamizu K, Han L, Tsuji T, Koga Y. Effects of krill oil containing n-3 polyunsaturated fatty acids in phospholipid form on human brain function: a randomized controlled trial in healthy elderly volunteers. Clinical interventions in aging. 2013;8:1247-1257.
- Rundblad A, Holven KB, Bruheim I, Myhrstad MC, Ulven SM. Effects of krill oil and lean and fatty fish on cardiovascular risk markers: a randomised controlled trial. J Nutr Sci. 2018;7:e3.
- Lemaitre-Delaunay D, Pachiaudi C, Laville M, Pousin J, Armstrong M, Lagarde M. Blood compartmental metabolism of docosahexaenoic acid (DHA) in humans after ingestion of a single dose of [(13)C]DHA in phosphatidylcholine. Journal of lipid research. 1999;40(10):1867-1874.
- Suzuki Y, Fukushima M, Sakuraba K, Sawaki K, Sekigawa K. Krill Oil Improves Mild Knee Joint Pain: A Randomized Control Trial. PloS one. 2016;11(10):e0162769.
- Kidd PM. Omega-3 DHA and EPA for cognition, behavior, and mood: clinical findings and structural-functional synergies with cell membrane phospholipids. Alternative medicine review : a journal of clinical therapeutic. 2007;12(3):207-227.