If you’ve heard about fish oil supplements for your heart health and as an anti-inflammatory, start getting excited about krill oil.
Krill oil is an omega-3 fatty acid supplement that contains the same omega-3 fatty acids as fish oil supplements, but with some additional antioxidants and phospholipids that may make it superior to fish oil.
Dietary guidelines recommend eating at least eight ounces of fatty fish per week[*]. And studies show that taking omega-3 supplements containing EPA and DHA can improve your health and prevent disease, especially if you don’t eat enough seafood[*][*][*].
Taking krill oil supplements may help:
- Prevent heart disease
- Promote healthy brain function
- Reduce inflammation
- And more
In this article, you’ll learn how krill oil works, its many health benefits, how to take it, and other essential information that will help you decide whether to take this supplement.
Krill oil is a marine oil sourced from tiny, shrimplike crustaceans. You’ll recognize krill as the main food source for larger sea creatures, from fish to whales.
Krill oil contains the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Unlike fish oil, krill oil also provides antioxidants and phospholipids, which enhance its stability and bioavailability.
The word “krill” means “whale food” in Norwegian. While there are at least 85 known species of krill, most krill oil is harvested from Euphausia superba (Antarctic krill), a small, reddish-pink, shrimp-like crustacean about two inches in length found in the Antarctic ocean.
Krill are an essential component of marine ecosystems; they feed on microscopic, single-celled phytoplankton, and in turn provide nourishment to birds, squid, fish, and whales.
Because krill are smaller and lower in the food chain than most fish, they contain less mercury and other contaminants than larger marine species — a huge reason more people are looking to krill over fish oil for their omega-3s[*].
When you eat seafood or take omega-3 supplements like krill oil, the omega-3 fatty acids can decrease systemic inflammation, lower your cholesterol, and reduce the risk of your blood platelets forming dangerous clots.
Along with EPA and DHA, krill oil contains other fatty acids including:
- Arachidonic acid
- Behenic acid
- Lignoceric acid
- Ln-9 neuronic acid
- Linoleic acid
- Ln-9 oleic acid
- Stearic acid
- Pentadecanoic acid
- Palmitic acid
- Myristic acid[*].
Phospholipids like phosphatidylcholine in krill oil not only improve the bioavailability of EPA and DHA, they also have brain and cellular health benefits thanks to their anti-inflammatory and antioxidant properties[*][*][*][*].
Krill oil contains vitamins A, vitamin E, B12, and folate, all of which are great for inflammation and brain health[*].
And because krill feed on marine phytoplankton, krill oil also contains astaxanthin, an antioxidant that can cross the blood-brain barrier and protect your brain and central nervous system from oxidative stress[*][*].
#1: Improves Heart Health
Heart disease is the number one killer of adults in developed countries, but taking omega-3 supplements like krill oil supports heart health and may reduce your risk of heart disease[*].
Krill oil does this in a couple of ways. Krill oil has been shown to increase HDL (“good”) cholesterol levels in people with high cholesterol, which is associated with a lower risk of heart problems[*].
Some rodent studies also show how krill oil may affect heart health and blood pressure in humans.
In a mouse study of atherosclerosis (inflammation and narrowing of the arteries) the addition of krill oil to mouse diets inhibited plaque development and reduced the incidence of atherosclerosis.[*] Another rodent study showed that krill oil reduced blood pressure[*].
#2: Promotes Healthy Brain Function
The omega-3 fatty acids, antioxidants, and phospholipids in krill oil may enhance brain function and protect your brain and central nervous system from harm.
Of the two primary omega-3 fatty acids found in krill oil, docosahexaenoic acid (DHA) is essential for brain development and regeneration, while eicosapentaenoic acid (EPA) helps regulate mood and behavior[*].
The phospholipids in krill oil have additional antioxidant and anti-inflammatory benefits[*].
Phospholipids like phosphatidylcholine can reduce damage from oxidative stress and may prevent depression, dementia, and other forms of mental and cognitive dysfunction[*].
In a double-blind, randomized controlled trial of 45 men aged 61-72, taking two grams of krill oil per day for twelve weeks improved their performance of mental calculations as well as working memory tasks[*].
A study of the effects of dietary krill oil in aging mice found that the supplement enhanced task performance, protected against oxidative damage, and helped prevent neurodegenerative disease[*].
#3: Reduces Inflammation
Inflammation normally happens when your body releases chemical messengers and immune cells to aid in the healing process after an injury.
However, low-grade inflammation occurs when your body releases these same chemicals in response to inactivity, obesity, high levels of blood sugar, or stress.
Chronic inflammation is linked to arthritis, heart disease, dementia, and other health issues, but taking omega-3 fatty acid supplements like krill oil can reduce inflammation in your body.
In a study of 90 patients with heart disease or arthritis, taking krill oil reduced their inflammatory markers compared to placebo and also reduced their stiffness, impairment, and pain[*].
A separate study found that krill oil reduced inflammatory markers after exercise in rowers[*].
#4: Lowers Cholesterol and Triglycerides
Taking krill oil supplements can improve your blood lipid levels by lowering LDL (“bad”) cholesterol, raising HDL (“good”) cholesterol, and decreasing triglyceride levels[*][*][*][*][*]. Krill oil may even be more effective at increasing good cholesterol, compared to fish oil[*].
#5: May Suppress Cancer Cell Growth
In vitro (cultured cell line) experiments show that the omega-3 fatty acids in krill oil may inhibit human osteosarcoma cell proliferation and induce apoptosis (cell death) in several different types of human colorectal cancer cells[*][*].
#6: Boosts Immune Function
In addition to killing cancer cells, krill oil has also been shown to strengthen your immune system.
In a six-week trial involving 37 healthy young male and female volunteers, krill oil increased levels of natural killer cell cytotoxic activity and peripheral blood mononuclear counts of interleukin-7 (IL-7) compared to exercise with no krill oil[*].
More studies would be helpful, but these effects may point to possible anticancer activity and improved immunity to certain diseases for people who take krill oil.
A healthy gut microbiome is also good for immune health, and krill oil may help with that, too.
#7: Enhances Gut Health
Krill oil supplements may alter your gut microbiome for the better, reducing intestinal inflammation, improving wound healing, and restoring integrity to the lining of your gastrointestinal tract (GI tract).
A mouse study examined the effects of krill oil on the microbiome and other health markers. The mice in question were fed a high-fat, high-sugar diet designed to cause high triglycerides, high cholesterol, and obesity[*].
Mice that received krill oil along with their unhealthy food regimen had lower cholesterol, less weight gain, and altered gut flora compared to mice that didn’t[*].
In an in vitro model of E. coli infection, krill oil administration reduced inflammation, sped wound healing, increased cell survival, and reduced bacterial invasion[*].
#8: Increases Lean Muscle Mass
Krill oil may increase lean muscle mass gains from resistance training[*].
In a double-blind, placebo-controlled study of 21 healthy participants, three grams of daily krill oil during an eight-week resistance training program increased lean muscle mass and strength levels in participants who received the supplement[*].
#9: Eases PMS Symptoms
Multiple studies have found that omega-3 supplements containing EPA and DHA can decrease pain during women’s cycles and mitigate other premenstrual syndrome (PMS) symptoms, including depression, fatigue, bloating, and lack of focus[*].
A double-blind, randomized control with 70 female participants found that krill oil decreased their stress levels, improved their depression, lowered their irritability, and decreased their use of drugs for pain relief[*].
The same study found that compared to fish oil, women who took krill oil took significantly less medication for pain.
Premenstrual pain isn’t the only discomfort krill oil may help mitigate.
#10: Helps Dry Eyes
According to a study involving 32,470 women, diets low in omega-3 fatty acids are more likely to cause dry eye disease, a painful condition that can result in poor vision[*].
In a separate double-blind, randomized study of 54 participants, 1.5 grams of daily krill oil reduced eye inflammation, redness, and other dry eye symptoms over 90 days[*].
Taking krill oil supplements is a safe and effective way to increase your intake of the omega-3 fatty acids EPA and DHA.
Most krill oil capsules are smaller than fish oil capsules and are less likely to cause fishy aftertaste and burping.
The best time to take krill oil supplements is before meals. You can take your daily dose of krill oil in a single dose, or two divided doses.
Dosing Krill Oil
While the American Heart Association recommends 250-500 milligrams of combined EPA and DHA per day, most studies of krill oil demonstrating health benefits use between 300 milligrams and three grams of krill oil, providing approximately 45-450 milligrams combined EPA and DHA per day[*].
If you’re taking krill oil for wellness and disease prevention, try taking between one and three grams of krill oil per day.
According to one study, krill oil has anti-inflammatory benefits when taken at a relatively low dose of 300 milligrams per day[*].
If you are taking krill oil supplements for anti-inflammatory benefits, you could start with a 300-milligram daily dose to gauge the effects, then consider adding more after several weeks.
Side effects of taking krill oil supplements are rare and are usually mild. In studies, the most common reported side effects were fishy breath, headache, diarrhea, bloating, stomach cramps, and constipation[*].
If you have an allergy to seafood, shellfish, or crustaceans, don’t use krill oil without speaking to a physician first.
People with bleeding disorders, or who are taking blood thinners or other medications or supplements with blood-thinning properties like aspirin or NSAIDs, should use krill oil cautiously and with medical supervision.
Both krill and fish oil can increase the effects of blood-thinning drugs. If you have surgery coming up, stop taking krill oil for at least two weeks before and after surgery.
There is a chance that krill oil supplements could lower your blood sugar or enhance the action of hypoglycemic drugs. If you have type 2 diabetes or use drugs to manage your blood glucose, monitor your blood sugar carefully and speak to your doctor first if you want to take krill oil.
Women who are pregnant or breastfeeding should also consult their doctors before taking krill oil.
The Takeaway: Krill Oil is The New Fish Oil
Krill oil supplements can improve your heart health, enhance cognition, decrease inflammation, ease PMS symptoms, and more.
Taking krill oil provides all the same health benefits as fish oil, but krill oil has several distinct advantages.
Krill oil is also more stable at room temperature than fish oil thanks to its antioxidant content, and it also contains vitamins and phospholipids not found in fish oil.
Because the EPA and DHA in krill oil are attached to phospholipids, it’s also more bioavailable than fish oil. That means a lower dose of krill oil has equivalent effects to a higher dose of fish oil[*][*].
The takeaway? Omega-3 supplements like krill oil are an excellent idea if you don’t eat seafood often, or if you want to improve your omega-3 to omega-6 ratios for disease prevention and better health.