Krill oil is an oil component derived from Antarctic krill (a type of zooplankton) that contains three important nutrients in abundance:
① EPA & DHA (Omega-3 fatty acids)
② Lecithin (phospholipids)
③ Astaxanthin
EPA & DHA are also found in fish oils, and there are products available that contain salmon oil, tuna oil, and carp oil. There is a difference in the composition of EPA & DHA in fish oil and krill oil.
Fish Oil: Triglyceride-type EPA/DHA
Krill Oil: Phospholipid-type EPA/DHA
Because phospholipids are components of cell membranes, phospholipid-type EPA & DHA are easily absorbed by the body, can pass through the blood-brain barrier (BBB), and are advantageous for brain function, aiding in the improvement of the nervous system.
In addition, krill oil contains the powerful antioxidant astaxanthin, which helps to prevent the oxidation of omega-3 fatty acids and maintain high-quality stability.
監修獣医師：林美彩 所属クリニック：chicoどうぶつ診療所
代替療法と西洋医学、両方の動物病院での勤務経験と多数のコルディの臨床経験をもつ。 モノリス在籍時には、一般的な動物医療（西洋医学）だけでは対応が困難な症例に対して多くの相談を受け、免疫の大切さを痛烈に実感する。
ペットたちの健康維持・改善のためには薬に頼った対処療法だけではなく、「普段の生活環境や食事を見直し、自宅でさまざまなケアを取り入れることで免疫力を維持し、病気にならない体づくりを目指していくことが大切である」という考えを提唱し普及活動に従事している。
所属：
Benefits of Krill Oil
・Prevents brain aging
・Improves hyperlipidemia
・Enhances liver function
・Boosts reproductive function
・Prevents myocardial infarction
・Reduces inflammation from arthritis
・Lowers blood glucose levels
For more information on krill oil, please refer to this article:
◆Krill Oil’s Anti-inflammatory and Dementia Prevention Effects
Below is a summary of research papers on krill oil.
Research on Krill Oil
1. The Effect of Neptune Krill Oil on Clinical Course of Hyperlipidemia
Source: Alternative Medicine Review, Vol9, No.4, 420-428(2004)
It was found that consuming 1-3g of krill oil per day effectively reduced blood pressure, total cholesterol, triglycerides, LDL (bad cholesterol), and increased HDL (good cholesterol).
2. Krill Oil Reduces Left Ventricular Hypertrophy in Rats Post Myocardial Infarction
Source: Lipids in Health and Disease, 10:245(2011)
The effect of krill oil was investigated on left ventricular remodeling (a condition of the heart where the left ventricle becomes enlarged) post-experimental myocardial infarction. The group pretreated with krill oil showed significant reduction in left ventricular hypertrophy compared to the untreated group.
3. Intake of Krill Oil-Supplemented Diet Suppresses Fatty Liver in Rats on a High-Fat Diet
Source: PLoS ONE 7(6), e28797(2012)
Krill oil supplementation led to significant activation of carnitine palmitoyltransferase I (CPT-I, which facilitates the binding of L-carnitine and fat) and an increase in carnitine levels, promoting fatty acid oxidation in the liver. Krill oil inhibited the uncoupling effect of high-fat diets, maintained mitochondrial oxidative phosphorylation, suppressed weight gain, and reduced oxidative damage of lipids and proteins typically observed in animals fed a high-fat diet.
4. Potential of Fats and Health – Krill Oil and Cardiovascular Health
Source: Food Style 21, Vol.16, 49-51(2012)
Feeding superba krill oil (extracted only from Antarctic krill rich in omega-3 fatty acids EPA and DHA) to Zucker obese rats and heart failure model rats showed beneficial effects on cardiovascular health.
5. Comparison of Inflammation and Lipid Regulation Between Krill Oil and Fish Oil in TNF-α Gene-Introduced Mice
Source:
The effects of fish oil and krill oil on lipid homeostasis and inflammation were investigated in model animals chronically exposed to low levels of human tumor necrosis factor (hTNF-α).
Administering krill oil was found to not only reduce plasma triacylglycerol and total cholesterol levels and promote β-oxidation in mitochondria and peroxisomes but also regulate lipid metabolism by improving overall carnitine turnover. In the case of fish oil, although it did not exhibit as significant an effect on reducing plasma triacylglycerol as krill oil, it significantly improved total cholesterol levels. There was no prominent difference between the krill oil and fish oil groups concerning inflammatory cytokine values.
6. Effects of Krill Oil Intake on Blood Lipid Levels
Source: Pharmacology & Therapeutics, Vol. 43 No. 5, 679-685 (2015)
A study involving 166 Japanese individuals investigated the effects of krill oil (1g/day) on lipid metabolism, particularly its impact on plasma triglyceride levels. Although most indicators showed no significant changes before and after krill oil intake, a notable decrease in triglyceride levels was observed in subjects who initially exhibited above-normal triglyceride levels, whereas those with normal triglyceride levels did not show any effect.
7. Science of Blood Vessels: Potential of EPA and DHA Derived from Krill Oil – Current Status and Challenges
Source: Food Style 21, Vol. 20, No. 10, 50-52 (2016)
In Japan, a report from the “Functional Food Evaluation Model Business” has given the highest scientific evidence level “A” to EPA and DHA for cardiovascular risk reduction and lowering plasma triglyceride levels, including a well-established mechanism of action. Unlike fish oil, where EPA and DHA are components of triglycerides, in krill oil they are incorporated into phospholipids, offering superior acute effects and no fishy aftertaste. Furthermore, krill oil contains the antioxidant astaxanthin, which prevents fatty acid oxidation and helps maintain product quality and stability.
8. Evaluation of Neptune Krill Oil on Chronic Inflammation and Osteoarthritis
Source: Journal of the American College of Nutrition, Vol. 26, No. 1, 39-48 (2007)
A randomized double-blind placebo-controlled trial was conducted to evaluate the effect of Neptune krill oil on CRP (C-reactive protein, an inflammation marker) in patients with chronic inflammation. Seven days after initiating intake, the placebo group showed an increase in CRP, while the Neptune krill oil group saw a 19.3% decrease. This reduction continued at 14 and 30 days (p<0.001). Furthermore, the WOMAC score (a measure of knee function: higher scores indicate worse function) was significantly reduced. While the placebo group showed an increase in CRP until day 14, it saw a 25.1% reduction by day 30. These results indicate that daily intake of 300mg/day Neptune krill oil can suppress inflammation and alleviate arthritis symptoms within 7-14 days.
9. Krill Oil Improves Mild Knee Pain: A Randomized Controlled Trial
Source: PLOS ONE 11(10): e0162769 (2016)
To determine the effect of krill oil on mild knee pain, a six-month randomized double-blind placebo-controlled trial was conducted from September 2014 to March 2015 with 50 adults (ages 38-85) experiencing mild knee pain. Participants received either 2g of krill oil or placebo. Improvements were observed in both groups using the JKOM (Japanese Knee Osteoarthritis Measure) and JOA (Japanese Orthopedic Association) standards, but the krill oil group showed significant improvements in knee pain and stiffness on two JKOM items, as well as notable reductions in sleep-related and standing knee pain, and increased knee range of motion. These findings suggest that krill oil intake (2g/day for 30 days) can improve self-reported symptoms of mild knee pain in adults.
10. Effects of Krill Oil and n-3 Polyunsaturated Fatty Acids on Proliferation and Migration of Human Osteosarcoma Cells
Source: Current Drug Targets, Vol. 19, No. 5, 479-486 (2018)
An experiment was conducted on the proliferation inhibition of human osteosarcoma cells exposed to krill oil, fish oil, EPA, and DHA for 72 hours. Although there was no significant change 24 hours after exposure to fish oil, krill oil showed 23% inhibition of proliferation after 24 hours, 50% after 48 hours, and 64% after 72 hours. The inhibitory effect of krill oil was equivalent to 0.5 and 1 µM of doxorubicin, commonly used for osteosarcoma treatment. This suggests that krill oil, when used in combination with standard clinical treatments, may control the growth of primary tumors and more severe metastasis.
Next-Generation Omega-3 Material – Krill Oil ③: Liver Function Protection and Brain Function Improvement Effects of Nissui Krill Oil
Source: Food Style 21, Vol. 15, No. 12, 27-31 (2011)
Animal experiments using Nissui krill oil demonstrated its inhibitory effect on alcohol-induced liver damage. Additionally, an experiment using phospholipids isolated and purified from the same product indicated possible protection of nerve cells and promotion of hippocampal neurogenesis.
Krill Oil Shows Metabolic Effects Equivalent to Fish Oil at Low Doses in Healthy Volunteers
Source: Lipids, Vol. 46, No. 1, 37-46 (2010)
113 subjects with normal or slightly elevated total cholesterol and/or triglycerides were given either 6 capsules of krill oil (3g/day, EPA+DHA=543mg) or 3 capsules of fish oil (1.8g/day, EPA+DHA=864mg) for 7 weeks. Although there was no statistical difference between the krill oil and fish oil groups, it was demonstrated that the EPA and DHA in krill oil, even at 62.8% of the amount found in fish oil, can serve as an equivalent source of n-3 polyunsaturated fatty acids.
Krill Oil and Anti-Aging: Expectations for Chronic Inflammation and Lifestyle Disease Prevention
Source: Food Style 21, Vol. 16, No. 2, 26-30 (2012)
In obese individuals, the production of inflammatory adipocytokines (which increase the risk of hypertension, hyperglycemia, and thrombosis) is heightened, and suppressing chronic inflammation is expected to improve metabolic syndrome. In a clinical trial involving patients with moderate inflammation (myocardial infarction, rheumatoid arthritis, osteoarthritis), the intake of krill oil significantly reduced inflammation markers (CRP). Unlike fish oil, krill oil contains phosphatidylcholine, which can improve blood homocysteine—an atherosclerosis risk factor—as well as protect against alcoholic fatty liver and hepatitis B and C.
Development of Functional Food Ingredients: Functional Aspects of Krill Oil Derived from Krill
Source: Japan Food Science, Vol. 51, No. 7, 17-22 (2012)
① An alcohol administration test with Wistar rats showed liver protection effects.
② When aged ICR mice were administered krill oil, improvement in reproductive function was observed.
③ In a human clinical trial, indicators of brain function activation (oxygenated hemoglobin concentration) improved with krill oil intake, indicating enhanced brain function.
Physiological Activity of New Functional Material Krill Oil
Source: Food and Development, Vol. 49, No. 2, 8-11 (2014)
A double-blind trial was conducted over 12 weeks on 45 elderly men aged 60-72, divided into three groups: those receiving 2g/day of sardine oil (EPA 491mg + DHA 251mg = 742mg/day), those receiving 2g/day of krill oil (EPA 193mg + DHA 93mg = 285mg/day), and those receiving a placebo containing neither EPA nor DHA (2g of medium-chain fatty acids). In the krill oil group, increased concentration of oxygenated hemoglobin in the brain was noted, indicating significant brain activation.
For liver function, rats were given a single oral dose of olive oil 3mg/kg (control group), krill oil 200mg/kg (low dose group), or krill oil 1000mg/kg (high dose group), followed by a single oral dose of 12mL/kg alcohol after 1 hour to observe the effects on liver function.
In the group administered with krill oil, the increase in blood alcohol concentration, state of intoxication, and elevations in blood AST and ALT were suppressed, suggesting that krill oil has a function to mitigate liver damage. When krill oil was ingested during the creation of an alcoholic fatty liver model in rats, the formation of alcoholic fatty liver was inhibited.
16. Functionality of n-3 Polyunsaturated Fatty Acids Material Krill Oil
Source: Lipid Nutrition, Vol. 23, No. 1, 23-28 (2014)
Krill oil derived from Antarctic krill, rich in n-3 polyunsaturated fatty acids bound to phospholipids, has been confirmed through animal experiments to have effects such as liver function protection, inhibition and improvement of alcoholic fatty liver formation, and improvement of reproductive function. In human brain function improvement tests, it clearly demonstrated greater efficacy compared to triglyceride-type oil containing n-3 polyunsaturated fatty acids (fish oil).
17. Presence of Oils in the Beauty Field: Health and Beauty Benefits of Krill Oil
Source: Crebeaux, No. 83, 20-22 (2015)
Krill oil is characterized by its high content of EPA (over 13%) and DHA (over 5%) and its ease of absorption in the body. Known benefits include prevention of brain aging, improvement of hyperlipidemia, enhancement of liver function, improvement of reproductive anomalies, and prevention of myocardial infarction. Additionally, due to its content of astaxanthin, a known potent antioxidant, it is considered highly promising as an anti-fatigue food and for improving endurance.
Although research on krill oil is still ongoing globally, our laboratory is also studying the interaction between Cordy and krill oil (EPA/DHA extracted from Antarctic krill) and the effects of krill oil when administered alone.
監修獣医師：林美彩 所属クリニック：chicoどうぶつ診療所
代替療法と西洋医学、両方の動物病院での勤務経験と多数のコルディの臨床経験をもつ。 モノリス在籍時には、一般的な動物医療（西洋医学）だけでは対応が困難な症例に対して多くの相談を受け、免疫の大切さを痛烈に実感する。
ペットたちの健康維持・改善のためには薬に頼った対処療法だけではなく、「普段の生活環境や食事を見直し、自宅でさまざまなケアを取り入れることで免疫力を維持し、病気にならない体づくりを目指していくことが大切である」という考えを提唱し普及活動に従事している。
所属：