More and more studies are pointing to krill oil as being a superior alternative to fish oil. Both are excellent sources of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, the omega-3 fatty acids in krill oil are present in the form of phospholipids instead of triglycerides as seen in fish oil. Studies suggest that krill oil omega-3 fatty acids are more easily transported through the body because cell membranes are made up mostly of phospholipids. This may explain the higher bioavailability of krill oil compared to fish oil. The concentration of EPA and DHA in the blood was found to be higher among those taking krill oil over those taking the same amount of EPA and DHA from fish oil. This delivery through phospholipids allows for better absorption of omega-3 fatty acids in organs where they are needed the most, specifically the heart, brain and liver.

Omega-3 fatty acids from krill oil are better able to regulate blood lipids compared to fish oil. Studies have shown that krill oil can lead to a significant reduction in total cholesterol, LDL and triglycerides more effectively than fish oil. Regulation of blood lipids lowers the risk for cardiovascular disease.

Krill oil is also beneficial for brain health. A randomized, 12-week supplementation trial of elderly volunteers showed that krill oil is better able to improve cognitive function compared to those taking fish oil. This elevation in mental functioning may be attributed to the phospholipids in krill oil that help facilitate passage through the blood-brain barrier.

Krill oil can inhibit inflammation as evidenced by reduced levels of the inflammatory marker, C-reactive protein, in a randomized trial of subjects taking krill oil compared to placebo. An in vitro study of intestinal cells also showed decreased inflammation when exposed to krill oil. Arthritic symptoms such as knee pain have also been reported to improve with intake of krill oil.

Other benefits of krill oil include significant improvement of dysmenorrhea and other premenstrual symptoms as well as eye protection through better control of dry eye disease symptoms compared to fish oil. Animal studies have also shown anti-depressant-like effects of krill oil.
 
Choline
 
Krill oil has choline, a compound essential for cellular structure and function as well as various metabolic processes in the body. Although choline can be produced endogenously, dietary supplements may be necessary to meet the body’s daily requirements. A study by Aker Biomarine using Superba™ Boost krill oil supplementation resulted in increased levels of choline metabolites necessary to produce amino acids and other biochemical reactions.

Astaxanthin
 
A unique advantage of krill oil is that it has astaxanthin, a powerful antioxidant that has over 5000 times the antioxidant property of vitamins C and E. Astaxanthin acts like a natural preservative by protecting the omega-3 fatty acids in krill oil from oxidative damage. It is lipid-soluble so it is more easily absorbed through the cell membrane. It has been reported to protect the skin by reducing water loss and supporting collagen resulting in smoother, younger looking skin. Its structure allows for easier transport so that it is able to exert its antioxidant activity in all areas of the body even in the brain where it is able to cross the blood-brain barrier.

References:
 
Bunea, Ruxandra, et al. “Evaluation of the Effects of Neptune Krill Oil on the Clinical Course of Hyperlipidemia.” Alternative Medicine Review, vol. 9, no. 4, Dec. 2004, pp. 420–428. 
 
Cicero, Arrigo F.g., et al. “Lipid-Lowering and Anti-Inflammatory Effects of Omega 3 Ethyl Esters and Krill Oil: a Randomized, Cross-over, Clinical Trial.” Archives of Medical Science, vol. 12, no. 3, 1 June 2016, pp. 507–512., doi:10.5114/aoms.2016.59923. 
 
Costanzo, Manuela, et al. “Krill Oil Reduces Intestinal Inflammation by Improving Epithelial Integrity and Impairing Adherent-Invasive Escherichia Coli Pathogenicity.” Digestive and Liver Disease, vol. 48, no. 1, Jan. 2016, pp. 34–42., doi:10.1016/j.dld.2015.09.012. 
 
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:10.1016/j.ophtha.2016.09.023. 
 
Deutsch, Luisa. “Evaluation of the Effect of Neptune Krill Oil on Chronic Inflammation and Arthritic Symptoms.” Journal of the American College of Nutrition, vol. 26, no. 1, Feb. 2007, pp. 39–48., doi:10.1080/07315724.2007.10719584. 
 
Konagai, Chizuru, et al. “Effects of Krill Oil Containing n-3 Polyunsaturated Fatty Acids in Phospholipid Form on Human Brain Function: a Randomized Controlled Trial in Healthy Elderly Volunteers.” Clinical Interventions in Aging, vol. 8, 19 Sept. 2013, pp. 1247–1257., doi:10.2147/cia.s50349.