Quick Summary

Krill oil is a marine-derived supplement extracted from Antarctic krill (Euphausia superba), rich in omega-3 fatty acids, primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), mainly in phospholipid form. It is being studied for potential effects on omega-3 fatty acid status, inflammation, lipid metabolism, and cardiovascular health. However, current research is ongoing, and evidence remains limited and not definitive.

What Is It?

Krill oil is an oil derived from Antarctic krill (Euphausia superba), small crustaceans found in the Southern Ocean. This oil contains omega-3 polyunsaturated fatty acids (PUFAs), notably EPA and DHA, which are important components of human nutrition. Additionally, krill oil includes phospholipids, the antioxidant astaxanthin, and other lipid molecules.

How It May Work in the Body

Krill oil may influence health primarily through the provision of bioavailable omega-3 fatty acids EPA and DHA. These fatty acids are recognized for their role in modulating inflammation, supporting lipid metabolism, and maintaining cell membrane integrity. Krill oil’s omega-3s are largely bound to phospholipids, which could affect their incorporation into cellular membranes.

  • EPA and DHA in phospholipid form may enhance their uptake and incorporation into cell membranes compared to other forms such as triglycerides.
  • Omega-3 fatty acids can modulate inflammatory pathways, potentially leading to reduced markers of inflammation.
  • The astaxanthin content may confer antioxidant properties, helping to reduce oxidative stress.

Limitations: Most proposed mechanisms are based on knowledge of omega-3 fatty acids generally rather than krill oil specifically. Human evidence directly confirming these mechanisms for krill oil’s unique composition is limited, and precise pathways remain to be fully established in clinical studies.

Common Supplement Forms

  • Softgel capsules containing krill oil are the most common form available on the market.

Typical Dosage and How It Is Used

Recommended dosages of krill oil vary widely between products and in clinical studies. Currently, there is no official recommended daily intake (RDA) or adequate intake (AI) established specifically for krill oil or its constituents.

Since dosage ranges in research vary and no consensus exists, users should follow product labeling and consult healthcare professionals as needed.

Natural Sources

  • Antarctic krill (Euphausia superba) is the natural source of krill oil.

Absorption and Bioavailability

One distinguishing feature of krill oil is that its omega-3 fatty acids are predominantly bound to phospholipids, unlike fish oil where these fatty acids are mainly in triglyceride form. This difference may influence absorption and bioavailability, potentially allowing more efficient incorporation of EPA and DHA into cell membranes.

However, evidence comparing absorption of omega-3s from krill oil versus other sources is limited, and further studies are needed to clarify any clinical significance.

Potential Benefits: What Does the Evidence Say?

Omega-3 Fatty Acid Status and Lipid Profile

Krill oil supplementation has been explored for its effects on blood levels of EPA and DHA, as well as on lipid parameters (such as cholesterol and triglycerides). Human clinical studies exist but are often small and heterogeneous, leading to mixed outcomes. While some findings suggest potential improvements in omega-3 status and lipid profiles, these results are not yet conclusive.

Limitations: Small sample sizes, variable study designs, and methodological differences limit the strength of conclusions. More large-scale, high-quality trials are needed.

Inflammation Modulation

Due to its EPA and DHA content, krill oil has also been investigated for possible effects on inflammatory markers. Some preliminary studies indicate a possible role in reducing inflammation. However, evidence is inconsistent and insufficient to confirm benefits conclusively.

Limitations: Direct, well-controlled human studies with sufficient power are currently lacking.

Side Effects and Safety

Krill oil is generally considered safe for most people when taken at typical supplement doses. Current evidence does not list common side effects or specific contraindications; however, safety and interaction data specific to krill oil remain incomplete.

As with any supplement, quality and purity can influence safety.

Drug and Supplement Interactions

No specific interactions involving krill oil are well documented; however, due to its omega-3 fatty acid content, theoretical interactions with blood-thinning medications or other drugs affecting coagulation may exist. Consultation with a healthcare provider is advised if you take medications or other supplements.

Who Should Be Careful?

People who:

  • Are pregnant, breastfeeding, or planning pregnancy
  • Have medical conditions or take prescription medications
  • Are preparing for surgery or have bleeding disorders

Should consult a healthcare professional before using krill oil supplements.

Pregnancy, Breastfeeding and Special Populations

There is insufficient evidence regarding the safety and efficacy of krill oil supplementation during pregnancy and breastfeeding. Therefore, it is recommended that these populations seek medical advice before use.

Quality, Standardization and What to Look For

Quality varies between krill oil supplements. Look for products that:

  • Are from reputable manufacturers with third-party testing
  • Provide clear information on EPA and DHA content
  • Ensure freshness and protection from oxidation (e.g., antioxidant inclusion)

Standardization of active ingredients may help ensure consistency, but no universal standards exist for krill oil supplements.

Frequently Asked Questions

  • Is krill oil better than fish oil? Krill oil contains omega-3s in a phospholipid form, which may influence absorption, but current evidence does not conclusively show that krill oil is superior to fish oil.
  • Are there any official health claims for krill oil? There are no authorized health claims for krill oil currently in the EU.
  • Can krill oil cause side effects? Side effects are uncommon, but comprehensive safety data are limited.
  • How much krill oil should I take? There is no official recommended daily intake. Dosages vary, so follow product recommendations and seek medical advice if uncertain.
  • Is it safe during pregnancy? Safety during pregnancy or breastfeeding is not established. Consult a healthcare professional before use.

Evidence Limitations

  • Lack of consistent, high-quality randomized controlled trials.
  • Small sample sizes and heterogeneity in study designs.
  • Insufficient specific safety and interaction data for krill oil.
  • No official authorized health claims by the EU for krill oil.

References

Last Reviewed

June 2024

Disclaimer: This page is for informational purposes only and is not intended to provide medical advice. Always consult a qualified healthcare professional before starting any new supplement, especially if you are pregnant, breastfeeding, have a medical condition, or take medications.