If you've been a long-time reader of my site, then you probably know just how much I value getting sufficient omega-3 fats in your diet. In a perfect world, you can get all the omega-3s you need from fish, but because a majority of the fish supply is now contaminated with heavy metals like mercury,1 then you'll have to resort to other sources to provide you with this valuable nutrient.
One of my personal favorites for omega-3 supplementation is high-quality krill oil. In this article, you'll discover the wealth of benefits you can get from krill oil and why it's a hundred times better than typical fish oil.
What Is Krill Oil and Where Does It Come From?
Krill oil is a marine oil that is known for providing animal-based omega-3 fats, antioxidants and beneficial substances known as phospholipids2,3 – this last item is particularly important, as it plays a significant role in the absorption of these nutrients (more about this later). It is harvested from krill (Euphausia superba), a small shrimp-like crustacean.4
The humble krill measures only about 2.4 inches in length — but don't let its size fool you. Krill is a crucial component of the global food chain, as it serves as the fuel that keeps the Earth's marine ecosystems consistently running. While it feeds on microscopic, single-celled plants called phytoplankton, hundreds of different creatures — birds, squid, other fish and even whales — feed on krill in turn.5
There are 85 known krill species, and in Antarctica, their biomass is said to be around 379 million metric tons.6 Krill are also found in oceans off Japan and Canada.7 Interesting trivia from National Geographic: "During certain times of year, krill congregate in swarms so dense that they can be seen from space!"8
Aside from being highly sustainable, krill are also known for their longevity — they can live from five to 10 years,9 which is amazing, considering they're very heavily hunted. This makes Antarctic krill oil a good and eco-friendly choice for an omega-3 supplement.
Krill Oil Versus Fish Oil: Which One Is Better?
As opposed to krill oil, fish oil is extracted from oily, cold-water fish, particularly their liver. Common examples of fish oil sources are herring, halibut, mackerel, salmon, albacore tuna and cod, which may be deep-ocean farmed or wild-caught. In some instances, fish oil is extracted from seal or whale blubber.10
While often interchanged, there are notable differences between the two, and if you thoroughly examine them, you'll note that krill is the superior option. Here are some reasons why krill oil is better than fish oil:
• Has a higher potency — Krill oil not only has 48 times the antioxidants as fish oil, but also has a higher potency in its metabolic effects, meaning you need far less to reap the benefits. One study published in the Lipids journal confirms this, wherein subjects taking krill oil only required 63 percent of what those taking fish oil had to consume to achieve the same results.11
• Is free of contaminants — The fish from which fish oil is extracted are often contaminated with heavy metals and mercury.12 Krill does not pose this risk because of their small size and due to the fact that they're at the bottom of the food chain.
• Has phospholipids — As mentioned, the phospholipid factor plays a significant role in how krill oil is absorbed by your body.13 Omega-3 fatty acids are water-soluble but cannot be transported in your blood while in their free form. Thus, they need phospholipids — something that krill oil readily has, but fish oil doesn't.
• Contains phosphatidylcholine — Composed partly of choline, a precursor for acetylcholine that sends nerve signals to your brain,14 and trimethylglycine, which has liver-protective effects,15 phosphatidylcholine is necessary for better absorption of omega-3 nutrients.16
If you opt for fish oil, your liver still needs to find and attach it to phosphatidylcholine, so it can be better utilized. But since krill oil already has phosphatidylcholine, it's then more superior in terms of bioavailability.
• Is less prone to oxidation — Krill oil has astaxanthin, making it more stable and less likely to oxidize in your body. Fish oil, which does not have astaxanthin, is more prone to oxidation, leading to the formation of free radicals, and increasing your need for antioxidants.17
• More environmentally sustainable — Krill harvesting is a stringently monitored process, and while there are claims saying that krill oil supplements are depleting the ocean's supply, the fact is that only a small percent of the overall krill biomass is harvested per year. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) notes that "the actual annual catch is around 0.3 percent of the unexploited biomass of krill."18
Other research also found that krill is superior to fish oil in terms of its influence on genetic expression and metabolism. A 2011 study published in the journal Frontiers in Genetics took a look at the livers of mice given krill oil versus those fed fish oil.19 The researchers found that krill oil enhances glucose metabolism in the liver, promotes lipid metabolism and helps regulate the mitochondrial respiratory chain — all of these effects are not seen in the fish oil group.
Furthermore, krill oil decreases cholesterol synthesis, while fish oil increases it. This means that krill oil will help lower your cholesterol and triglyceride levels and increase energy production, but fish oil does not offer either of these benefits.20,21
Also a cause for concern is fish oil's current processing practices. This is deeply problematic, as the final product rendered is very, very different from the natural oils you acquire from the whole fish. Read more about it in my article, "Are Many Fish Oils Synthetic?"
How Does Your Body Use the Omega-3s From Krill Oil?
What primarily gives krill oil its many health advantages is its omega-3 fatty acids. Omega-3s are polyunsaturated fatty acids (PUFAs) that are used by your body for various functions, such as digestion, blood clotting, muscle activity, memory and cognitive function, visual acuity and much more.22 They are also particularly important for proper cell division and bind to cell receptors to help regulate genetic function.23
However, your body cannot produce omega-3s, hence, they need to be acquired from your diet. Most people would contest that omega-3s can be derived from plant sources too, like chia, hemp and flaxseeds, but the omega-3s that you get from krill oil and fish are far more beneficial.
This is because the omega-3s in plant foods are in the form of alpha-linolenic acid (ALA). ALAs are short-chained PUFAs that need a particular enzyme24 for them to be converted to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — long-chain PUFAs that are more bioavailable and beneficial.
Norwegian scientist Nils Hoem, PhD., who specializes in omega-3 phospholipids, explains it further. According to him, short-chain fatty acids are simply food that provide a source of energy for the body. Meanwhile, long-chain PUFAs like EPA and DHA are structural elements that are the building blocks of your cells. This is the most significant difference between these two types of omega-3s. You can read more about my interview with Hoem in this article.
EPA and DHA are known for their numerous biological effects, particularly their anti-inflammatory benefits.25 Plus, they play a role in communication within the cell and between the cells. DHA in particular is very essential, since it's a component of every cell in your body and is crucial to brain health.26
Please take note that I'm not vilifying plant-based omega-3s. ALA is a very healthy fat with its own useful purpose. Your body needs it — but not in excessive amounts and not as crucially as EPA and DHA, which come from krill and other marine sources.
Krill Oil's Many Health Benefits
So what exactly does krill oil do for your health? For starters, it may help with at least two dozen diseases and health issues, such as:
- Cardiovascular disease and hyperlipidemia — Krill oil may help lower blood pressure, triglyceride levels and LDL (bad) cholesterol levels, while raising HDL (good) cholesterol levels27,28
- Neurological/cognitive dysfunction — This includes brain aging, memory loss and learning disorders.29 The omega-3 fats in krill oil may also be helpful for ADHD, dyslexia and autism,30 as well as Parkinson's disease31
- Inflammation — It also helps reduce C-reactive protein32
- Oxidative stress33
- Osteoarthritis and rheumatoid arthritis (RA)34,35
- Metabolic syndrome,36 which includes obesity, Type 2 diabetes and fatty liver
- Crohn's disease and other inflammatory bowel diseases (IBD)37
- Dysmenorrhea and premenstrual syndrome (PMS)38
- Kidney disease39
- Colon cancer40
- Preventing premature delivery41 and promoting brain development in infants42
- Autoimmune diseases like nephropathy43 and lupus44
Of course, if you include omega-3 fats in the equation, then this list would greatly expand. In particular, omega-3s may help:
- Improve endothelial function (which helps promote growth of new blood vessels)45
- Boost your mood46
- Reduce your risk of Alzheimer's disease47
- Maintain bone health48
- Reduce your risk of death from all causes49
Studies on Krill Oil Confirm Its Potency
Many of the mentioned benefits above have been well-backed by scientific research. Here are a few notable examples:
- Reduced cholesterol levels — An animal study published in the Journal of Animal Physiology and Animal Nutrition found that rats given krill oil supplements for six weeks reduced their cholesterol levels by 33 percent.50 In a separate study,51 this time conducted on patients taking statins, taking krill oil along with statins and a low-fat diet reduced cholesterol levels by 20 percent.
- Improvements in osteoarthritis and RA patients — A study conducted on patients with these ailments found that those who took 300 milligrams of krill oil daily had reduced pain, inflammation, stiffness and functional impairment after just seven days. Better improvements were seen after 14 days.52
- Metabolic syndrome — A rat study looked at the risk factors linked to metabolic syndrome, particularly endocannabinoids, which stimulate your cannabinoid receptors and produce a variety of physiologic processes. The researchers found that mice that had increased endocannabinoid levels (after being fed an unhealthy diet) had a significant reduction after taking krill oil.53
Krill Oil May Have Some Side Effects
One of the most common complaints against fish oil is that it leaves behind a fishy aftertaste or results in reflux or belching of fishy flavors.54 However, this effect is significantly reduced in krill oil, as long as you purchase a high-quality brand. Even so, take note that some krill oil brands (particularly poor quality ones) may also cause side effects like heartburn, upset stomach, bad breath, nausea and loose stools.55
While krill oil is generally safe for most people, it is still important to consult your physician if you are suffering from any illness or taking any medication before taking this supplement (or any dietary supplement). If you are pregnant or breastfeeding, consult your physician prior to taking krill oil.56
If you are taking anticoagulants like warfarin or any other blood thinners, have a blood coagulation disorder, do not take krill oil, as it may slow down blood clotting. There may be dangers as well for people who have allergies to seafood who take krill oil.57
The Best Sources of Krill Oil: Here's What to Look for When Buying This Supplement
When looking for a krill oil supplement, I advise that you only purchase one that has been certified by the Marine Stewardship Council (MSC). This nonprofit organization aims to transform the seafood market to a sustainable basis and it does this by recognizing and rewarding fisheries that follow sustainable fishing practices.
When the krill oil is MSC-certified, it means that every part of the manufacturing process — from the krill harvesting to how it is manufactured — has gone through a high global standard, ensuring that the product is truly sustainable. The MSC also has a chain of custody traceability program, which seafood providers can renew on a yearly basis.58 Keep an eye out for these other factors as well:
- The krill oil must be produced using Antarctic krill, which is the most abundant.
- It should be free of heavy metals, dioxins, PCBs and other contaminants.
- It should be cold-processed, which preserves its biological benefits. Avoid krill products that use hexane to extract the oil — unfortunately, many popular krill oil brands use this dangerous chemical agent.
- The krill oil should be encased in hard capsules instead of soft gels. Soft gels allow more oxygen to enter, promoting oxidation. Even if krill oil naturally contains astaxanthin that can reduce oxidation, hard capsules add another protective layer, giving you a product that's optimally fresh and effective.
Krill Is King When It Comes to Omega-3s, but Here's Another Great Choice You Can Try
A high-quality krill oil supplement outperforms fish oil in terms of efficiency, sustainability and cost. However, you may also want to get this valuable nutrient from certain types of seafood, particularly those that have not been contaminated with heavy metals and other pollutants.
One of the best sources is wild-caught Alaskan salmon. Small fish types like anchovies and sardines are also wonderful options, and is highly recommended for those who truly need an omega-3 boost.
Frequently Asked Questions (FAQs) About Krill Oil
Q: Is krill oil safe?
A: Yes, krill oil is generally safe for most people. However, certain individuals, such as those who have seafood allergies, have a blood clotting disorder or are taking anticoagulants must refrain from using this supplement, as it may lead to unpleasant or even serious effects.59
Q: What is krill oil used to treat?
A: Over two dozen health conditions are said to benefit from krill oil, including cardiovascular disease, osteoarthritis and rheumatoid arthritis, kidney disease, cognitive or neurological dysfunction and autoimmune diseases.
Q: Can krill oil cause heartburn?
A: Some krill oil brands may cause heartburn. To avoid this, take krill oil along with a full meal. If this does not work, try reducing the dose or stop taking the product for a while.60
Q: Is there mercury in krill oil?
A: There is no mercury in krill oil. This is because krill, which is at the bottom of the food chain, feeds on phytoplankton. It does not consume mercury-contaminated fish.
Q: Is krill oil the same as omega-3?
A: Krill oil is a marine oil extracted from krill, a shrimp-like crustacean, while omega-3s are polyunsaturated fatty acids (PUFAs) that are used by your body for various functions. Hence, krill oil is not directly synonymous to omega-3s, technically speaking, but it does contain these beneficial fatty acids, particularly DHA and EPA.