Krill oil as a dietary supplement
Krill oil is a dietary supplement derived from tiny crustaceans found in the Antarctic Ocean, often marketed as an alternative to fish oil. It is rich in omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), along with omega-6 fatty acids, the antioxidant astaxanthin, and phospholipids. Proposed health benefits of krill oil include support for cardiovascular health, management of high cholesterol and blood pressure, and relief from dysmenorrhea and premenstrual syndrome. Some studies suggest that krill oil may be more effective than fish oil for these conditions, as well as for potential inflammation reduction and improved cholesterol profiles.
Therapeutic dosages typically range from 1 to 3 grams per day, with various studies indicating positive effects on cholesterol and blood sugar levels. While generally considered safe, krill oil may cause mild digestive issues and allergic reactions, particularly in individuals allergic to seafood. There are also concerns about its blood-thinning properties, indicating that those at risk for bleeding should consult a healthcare professional before use. Ongoing research suggests krill oil may also contribute to cognitive health and skin benefits, though further studies are needed to confirm these effects.
Krill oil as a dietary supplement
- DEFINITION: Natural food product promoted as a dietary supplement for specific health benefits.
- PRINCIPAL PROPOSED USES: Dysmenorrhea, cardiovascular health (high cholesterol and high blood pressure), premenstrual syndrome
- OTHER PROPOSED USES: Allergies, Alzheimer’s disease, angina, ankylosing spondylitis, anti-cancer, anti-inflammatory, arthritis, asthma, attention deficit disorder, bipolar disorder, borderline personality disorder, cancer treatment support, chronic fatigue syndrome, cognitive health, congestive heart failure, Crohn’s disease, depression, diabetic neuropathy, eczema prevention, epilepsy, eye health, gout, heart disease prevention, human immunodeficiency virus infection, hypertension, kidney stones, liver disease, lupus, macular degeneration, male infertility, mental health, migraine headaches, multiple sclerosis, osteoporosis, postpartum depression, pregnancy support, prevention of premature birth, prostate cancer prevention, psoriasis, Raynaud’s phenomenon, retinitis pigmentosa, rheumatoid arthritis, schizophrenia, sickle-cell anemia, skin health, stroke prevention, surgery support, ulcerative colitis, undesired cancer-related weight loss
Overview
Krill are tiny, shrimp-like crustaceans that flourish in the Antarctic Ocean and provide food for numerous aquatic animals. Oil made from krill appears on the market as an alternative to fish oil. Like fish oil, krill oil contains the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. Krill also contains omega-6 fatty acids, an antioxidant in the carotenoid family called astaxanthin, and substances called phospholipids.
Sources
Many grains, fruits, vegetables, sea vegetables, and vegetable oils contain significant amounts of essential fatty acids, but krill oil is an especially rich source. Carotenoids are also found in many foods, especially yellow-orange and dark-green fruits and vegetables. Carotenoids are not essential nutrients (with the exception that some can be converted to vitamin A), but they might offer some health benefits. Phospholipids are utilized in the body for numerous purposes, but they are not essential nutrients.
Therapeutic Dosages
A typical recommended dose of krill oil is 1 to 3 grams (g) daily.
Therapeutic Uses
Based on its omega-3 fatty acid content, krill oil would be expected to have many of the same effects as fish oil. A few studies have evaluated krill oil specifically. In one double-blind, placebo-controlled study, 120 people with high cholesterol were given krill oil, fish oil, or placebo. The three-month study showed that krill oil (taken at a dose ranging from 1 to 3 g daily, depending on body mass and what group the participants were assigned to) improved all aspects of the cholesterol profile compared with placebo. It was more effective than fish oil (taken at a fixed dose of 3 g daily). Krill oil also reduced blood sugar levels. In a large double-blind, placebo-controlled study published in 2022, researchers found krill oil lowered cholesterol and improved cardiovascular health.
Another double-blind study compared krill oil with fish oil for the treatment of symptoms of premenstrual syndrome and dysmenorrhea (menstrual cramps). This study had many problems in design and reporting, but it appeared to show that krill oil was more effective than fish oil for treating both of these conditions. One study conducted in the early twenty-first century hinted that krill oil might be helpful for both osteoarthritis and rheumatoid arthritis. Further study of krill oil continued to reveal its health benefits, including fighting inflammation and lowering the risk of heart disease by raising good, high-density lipoprotein (HDL) cholesterol levels and lowering blood lipids.
As the twenty-first century progressed, research on krill oil and its therapeutic benefits continued. Preliminary studies suggested krill oil might provide cognitive health benefits because it is rich in Omega-3 fatty acids. Animal studies indicated krill oil could be a vital adjuvant therapy for treating depression. One double-blind, placebo-controlled study found that krill oil supplementation may improve the symptoms of dry eye disease because of its anti-inflammatory properties. Preliminary studies indicated the astaxanthin found in krill oil could offer benefits for the skin by protecting from the sun and improving skin's elasticity. Although these suggested uses were promising, additional scientific study was necessary.
Safety Issues
Based on its known constituents, krill oil would be expected to have little to no toxicity. Side effects seen in studies are limited to occasional digestive distress and allergic reactions. The only known potential concerns relate to possible blood-thinning effects: fish oil is known to decrease blood coagulation, and in one case report, it increased the effect of the blood-thinning medication warfarin (Coumadin). People who are at risk of bleeding complications for any reason should consult a physician before taking krill oil. Maximum safe doses in young children, pregnant or nursing women, and people with severe liver disease have not been established. Individuals with a known allergy to seafood should not take krill oil.
Bibliography
Buckley, M. S., et al. "Fish Oil Interaction with Warfarin." Annals of Pharmacotherapy, vol. 38, 2004, pp. 50-52.
Bunea, R., et al. "Evaluation of the Effects of Neptune Krill Oil on the Clinical Course of Hyperlipidemia." Alternative Medicine Review, vol. 9, 2005, pp. 420-428.
Deinema, Laura A., et al. "A Randomized, Double-Masked, Placebo-Controlled Clinical Trial of Two Forms of Omega-3 Supplements for Treating Dry Eye Disease." Ophthalmology, vol. 124, no. 1, 2017, pp. 43-52, doi.org/10.1016/j.ophtha.2016.09.023. Accessed 8 Oct. 2024.
Deutsch, L. "Evaluation of the Effect of Neptune Krill Oil on Chronic Inflammation and Arthritic Symptoms." Journal of the American College of Nutrition, vol. 26, 2007, pp. 39-48.
Jones, Taylor. "6 Science-Based Health Benefits of Krill Oil." Healthline, 19 Aug. 2020, www.healthline.com/nutrition/krill-oil-benefits. Accessed 8 Oct. 2024.
"A Look at Krill Oil's Benefits." Cleveland Clinic Health Essentials, 17 Nov. 2021, health.clevelandclinic.org/krill-oil-vs-fish-oil. Accessed 8 Oct. 2024.
Sampalis, F., et al. "Evaluation of the Effects of Neptune Krill Oil on the Management of Premenstrual Syndrome and Dysmenorrhea." Alternative Medicine Review, vol. 8, 2003, pp. 171-179.
Zhang, Hao, et al. "Krill Oil Treatment Ameliorates Lipid Metabolism Imbalance in Chronic Unpredicted Mild Stress-induced Depression-like Behavior in Mice." Frontiers in Cell and Developmental Biology, vol. 11, 2023, p. 1180483, doi.org/10.3389/fcell.2023.1180483. Accessed 8 Oct. 2024.