Fish Oil Vs Krill Oil

Difference between fish and krill oilOmega-3 essential fatty acids include two major therapeutic acids – eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA shift the body’s balance of inflammation to reduce pain, cholesterol levels and risk of heart disease. Fish oil is the most popular supplemental form of omega-3 fats but a new shrimpy guy has recently hit the scene – krill.

Krill oil is extracted from a tiny crustacean that hangs around the icy waters of the Antarctic. Krill are on the bottom tier of the food chain – fish, whales, seals, penguins, squid and now humans are all competing for these nutrient-dense shrimp-like creatures.

Most fish oil is derived from salmon, anchovies, herring, tuna, cod, blue grenadier and menhaden – basically any oily, fatty fish. Each fish has a different concentration of EPA and DHA, resulting in a variety of concentrations within oil blends. Sardines and anchovies are particularly high in omega-3 fatty acids so they are often used to improve the concentration of EPA and DHA in high quality fish oil supplements.

Krill & Fish Omega-3 Differences

Both krill oil and fish oil are rich in EPA and DHA omega-3 fatty acids. What sets krill apart is that these omega-3s are packaged into phospholipids – a form that is easy for the human body to absorb and integrate. In fact, studies suggest that taking a lower dose of krill oil can yield the same therapeutic results as taking a high dose of fish oil [1]. Krill oil also contains choline and antioxidants which fish oil does not.

The concentration of EPA and DHA in fish oil is higher than krill oil, but is less absorbable and does not contain any antioxidants.

The ratio of EPA to DHA in a supplement can determine its effects. They work together to reduce cellular inflammation, but higher amounts of EPA will reduce inflammation throughout the skeletal muscles and joints while DHA has a higher affinity for the brain.

Both EPA and DHA from fish oil and krill oil have been shown to:

  • Reduce inflammation throughout the body
  • Alleviate symptoms of rheumatoid arthritis
  • Lower total and “bad” LDL cholesterol levels
  • Raise “good” HDL cholesterol
  • Severity of symptoms with depression, ADHD and anxiety
  • Relieve pain associated with many conditions including painful menstrual periods[2] [3] [4]

What The Evidence Says

Fish oil has been extensively researched over the last two decades and has strong evidence backing its use for lowering cholesterol, pain and inflammation [2][3][4].

  • An in-depth review in 2017 suggested that the most recent and thorough studies call into question the common belief that fish oil can prevent cardiovascular disease – it appears that it isn’t as effective as we once thought.

However, the researchers continue to recommend fish oil for people with coronary heart disease and those who have had a recent heart attack – even the most modest research shows a 10% reduced risk of death from a heart attack when taking fish oil [5]. Worth a shot, right?

There is no compelling evidence that fish oil can prevent a stroke, atrial fibrillation, or coronary heart disease in the face of other risk factors like poor diet and lifestyle choices, genetic influences, and co-morbidities [5].

Evidence for krill oil is still growing.

This is a polite way of saying that there is hardly any out there. One study showed that krill oil has the same effect as fish oil, but at a lower dosage meaning you don’t need to take as much to experience the benefits of omega-3 supplementation [1]. However, this study was performed on healthy young people with no risk of heart disease, arthritis or chronic inflammation – it may not produce the same effects for people not in good health.

A few more studies show that a particular brand of krill oil could reduce inflammation, arthritic symptoms and high cholesterol – however, the validity is slightly questionable as two of the authors of the studies were employees of the brand being tested [6] [7]. Unfortunate, as the results look really promising. Stay tuned for more research on krill – we have a feeling this little crustacean will attract more attention from the scientific community soon.

fish vs krill oil supplementsEnvironmental Considerations

Krill populations have dropped as much as 80% since the 1970s. Krill harvesting is increasing while their breeding ground, the Antarctic Peninsula, is warming faster than any other region on Earth and starving them of their food source – algae that grows beneath the ice. Declining numbers of krill mean less food for other species, particularly penguins, seals and whales. Some believe that increasing demand for krill oil supplements could contribute to the decline in krill and the animals that feed on it.

Fish oil has major environmental impacts as well. Over 90% of the world’s fisheries have become exploited or collapsed in the last 10 years [8], despite sustainable fishery guidelines setting catch limits for each species of fish [9]. Add to this the destruction of endangered and near-extinct species such as the whale shark – the increasing demand for fish oil in the US is driving up the slaughter of the rare whale shark by fish oil refineries in China [10]. Buying sustainable fish oil is one way to reduce environmental impact, but note that manufacturers do not have to disclose all the source of oils included in the supplement if they come under the banner of “fish oil”.

In conclusion: both krill oil and fish oil take their toll on the environment. Krill populations replenish much faster than fish and haven’t been declared as “overfished” – but that doesn’t mean it won’t happen. Whichever you choose, opt for a product with sustainable harvesting methods. Check for certification from the Krill Oil Standards Program (IKOS) and buy from reputable fish oil brands who disclose their harvesting practices.

How To Take Fish Oil and Krill Oil

Fish and krill oil supplements come in capsules, chewable tablets and liquids. All forms are bioavailable and have similar absorption rates. Pick what works for you. Take with food for best absorption and to reduce fishy breath.

Dosage: An average therapeutic dose is 1g – 3g of fish oil per day. Krill oil may exert the same benefits at 500mg – 1g. Speak to a qualified nutritionist for personal advice.

NOTE: Do NOT cook with fish or krill oil – the omega-3 fatty acids are degraded in heat. Don’t take fish or krill oil if it has a strong “fishy” odour – chances are it’s gone rancid and will contribute to more inflammation throughout the body.

CAUTION! It’s important to inform your doctor that you take fish oil or krill oil. These supplements can interact with some drugs, including blood thinners. Stop taking krill or fish oil at least 1 week before any kind of surgery.

Which Should You Supplement With?

In terms of availability and sheer concentrations, fish oil is everywhere and often dosed high. However there is no denying that Krill is more effective, potent, and contains added benefits.

You can view our top Fish and Krill Oil Omega Supplements here.

Alternatively, Vegans can view the best plant-based vegan friendly omega 3 supplements here.

Further Reading:

About James Lyons

James Lyons (BHSc Nutritional Medicine) is a clinical nutritionist, medical writer, and educator. He specialises in plant-based nutrition and is passionate about improving public access to reliable and accurate health information.

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