From the oceans of the ice-cold Antarctic, krill is making inroads into the sanctum of fish-derived fatty acids. Mark J. Tallon, PhD, investigates the state of the supply and science of this evolving market
The demand for fish oils is an interesting area. Unlike many nutraceuticals, they are not synthesized chemically, so they are not in infinite supply. From the early days of Seven Seas to industry giants such as Ocean Nutrition and Martek, the current omega-3s market has evolved significantly. In recent years, Neptune Krill Oil™ has led the way in regard to the science behind this tiny crustacean. All four peer-reviewed studies using Neptune Krill Oil revealed positive outcomes for health concerns ranging from premenstrual issues to chronic arthritis (see references at the article end).
It is possible to define the category by breaking it down into four main sources of omega-3s: fish derived, algal derived, plant derived and krill. As demand and science increase, all sources will contribute to the market for omega-3s.
Krill (Euphausia superba) is well known as a source of food for many marine animals. Recent research has highlighted the nutrient content of this shrimplike crustacean as a rich source of high-quality protein, while being lower in fat and higher in omega-3 fatty acids, antioxidants and phospholipids than other animal proteins.1
As a rich source of DHA and EPA, krill has drawn similarities with fish oils regarding potential health benefits. To date, the vast majority of inferences are based off the back of fish-derived fatty acids. However, fish-derived fish oils and krill-derived fish oils have a different nutritional composition despite both containing DHA and EPA. To really look at the potential of krill as an omega-3 source requires direct studies that demonstrate its efficacy.
Currently, there are only three direct human studies published as full papers that have assessed the health impact of krill in the form of krill oils.2,3,4 These works have examined three distinct areas of human health and provide a base of efficacy regarding product claims and a springboard for further clinical investigations.
PMS and dysmenorrhoea
Researchers from the University of Montreal's department of experimental surgery evaluated the effectiveness of krill oil on the management of premenstrual syndrome (PMS) and dysmenorrhoea (DM) compared to omega-3 fish oil.2 In a double-blind, randomised trial, 70 patients diagnosed with PMS were treated with either krill oil or omega-3 fish oils for 90 days.
Trial results support krill oil being significantly superior as a treatment intervention in those suffering from PMS and DM. A significant reduction in the number of emotional symptoms and analgesics used for DM was evident when compared to baseline and omega-3 fish oil.
The message from the authors suggests krill-based therapy is more effective than fish oil in treating PMS and DM symptoms. With the women's market for functional nutrients expanding, efficacious nutrients such as krill can offer an effective point of entry when combined with the right marketing message.
Lipid and cholesterol levels
In a randomised trial from McGill University (Canada), researchers assessed the effects of krill oil on blood lipids, including total cholesterol, triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL).3 A 90-day randomised intervention trial, with a 90-day follow-up, on 120 patients with hyperlipidemia was conducted with krill at a daily dose of 1g and 1.5g. Subjects were split into one of four groups with total cholesterol, triglycerides, LDL, HDL and glucose measured at baseline and 90 days:
Group 1: 2-3g/day krill oil
Group 2: 1-1.5g/day krill oil
Group 3: fish oil containing 180mg EPA and 120mg DHA per gram of oil at a dose of 3g/day
Group 4: placebo
Krill oil at a dosage of 1-3g/day (BMI-dependent) was found to be effective for reducing glucose and all blood-lipid parameters, compared to both fish oil and placebo. As an adjunct therapy, krill oil is significantly more effective than placebo or fish oil at reducing elevated lipid and glucose levels.3 Potential applications as a cardio and diabetic fortification and/or supplementation source are clear.
Arthritis heat and pain
In the final human study, krill was evaluated for reducing arthritic symptoms and inflammation in patients diagnosed with cardiovascular disease, rheumatoid arthritis and/or osteoarthritis.4 Patients also had increased levels of C-reactive protein (CRP). In a randomised, double-blind, placebo-controlled study of 90 patients, half received 300mg/day krill oil and half a placebo. Western Ontario and McMaster Universities (WOMAC) osteoarthritis scores and CRP levels were measured at baseline and days seven, 14 and 30.
After seven days of treatment, krill oil reduced CRP by 19.3 per cent compared to an increase of 15.7 per cent observed in the placebo group. After 14 and 30 days of treatment, krill oil further decreased CRP by 29.7 per cent and 30.9 per cent, respectively. The CRP levels of the placebo group increased to 32.1 per cent after 14 days and then decreased to 25.1 per cent at day 30. After seven days of treatment with krill oil, WOMAC pain scores were reduced by 28.9 per cent, reduced stiffness by 20.3 per cent and reduced functional impairment by 22.8 per cent. The results demonstrate that krill oil compared to placebo can significantly reduce arthritic symptoms and biological markers of inflammation within seven to 14 days.
No fish story
Despite the numerous commercial references trying to implicate studies on omega-3s and phosphatidylserine as being indicative of a krill-type effect, this is not the case. The truth is that, at present, there exists limited direct human data on the beneficial influences of krill.
However, those studies that do exist provide an excellent incentive to run more trials to highlight krill's potential across multiple health platforms. The future for krill may be beyond trying to compare and match itself to fish oil-derived omega-3s, but rather to focus on the difference, resulting in a differentiation in marketing. We are already seeing this in a small way through the development of krill-derived astaxanthin and, given its other unique nutrient matrix, new and novel health benefits are likely to be derived. In a category where supply may potentially struggle to meet demand, alternate options for clean and safe sources of omega-3s will flourish.
Mark J Tallon, PhD, is chief science officer of NutriSciences, a London-based consultancy firm. www.NutriSciences.net
1. Tou JC, et al. Krill for human consumption: nutritional value and potential health benefits. Nutr Rev 2007;65(2):63-77.
2. Sampalis F, et al. Evaluation of the effects of Neptune Krill Oil on the management of premenstrual syndrome and dysmenorrhea. Altern Med Rev 2003;8(2):171-9.
3. Bunea R, et al. Evaluation of the effects of Neptune Krill Oil on the clinical course of hyperlipidemia. Altern Med Rev 2004;9(4):420-8.
4. Deutsch L. Evaluation of the effect of Neptune Krill Oil on chronic inflammation and arthritic symptoms. J Am Coll Nutr 2007;26(1):39-48.