Written by Marcia J. Egles, MD. Participants receiving krill oil had an overall 10.2% reduction in serum triglyceride levels.
A recent study reports that daily supplementation with krill oil may lower serum triglyceride levels in Americans with elevated serum triglycerides (1). As with high cholesterol, high triglyceride levels are associated with increased risk of cardiovascular disease (2, 3). As many as a third of American adults have elevated levels (serum levels greater than 150 milligrams per deciliter) of this fatty particle in their blood (4).
Appropriate exercise and diet can improve high triglyceride levels. Dietary supplementation with fish oil has been shown to lower triglyceride levels by decreasing triglyceride production and increasing triglyceride clearance (5). Though not as well-studied as fish oil, krill oil has similarities to fish oil in that it too is rich in long-chain omega-3 polyunsaturated fatty acids. The polyunsaturated fatty acids in krill oil occur mainly in a phospholipid form rather than the triglyceride form found in fish oils (1).
The researchers of the krill study examined the efficacy of krill oil in lowering serum triglycerides. Krill oil is obtained from shrimp-like Antarctic krill. Prior studies done in rodents have shown that krill oil supplementation can reduce serum triglyceride levels (1).
The twelve-week study examined the effect of daily krill oil supplementation on the fasting triglyceride levels of 300 men and women with high triglyceride levels. The study participants were from two research centers, one in St. Charles, Missouri and the other in Fargo, North Dakota. To be included, the subjects were required to have fasting triglyceride levels in the range of 150 to 499 mg/dl (borderline high to high), be 21 to 79 years of age, and to consume relatively little seafood (not to exceed two servings per month). They had to be drug and alcohol-free on screening, and have body mass indices less than 35 kilogram per meter squared. Men comprised 69% of the group. Additionally, those with shellfish allergies were excluded, as they were presumed to be allergic to krill.
The subjects were randomly divided into five groups. One group was to receive daily olive oil placebo. The other four groups were assigned different daily doses of krill oil (0.5, 1.0, 2.0, and 4.0 grams). The study included a total of five visits for each participant: one for screening, one for collection of baseline information, one at day 7 to aid compliance, and two efficacy visits at weeks 6 and 12 to obtain blood samples after overnight fasting.
Because of variability in triglycerides levels in individuals over the twelve weeks, the study was underpowered to evaluate krill oil dosages as initially planned. Instead, all the krill oil subgroups were combined into one group for comparison against the placebo group. Relative to the placebo group, those who received the krill oil had an overall 10.2 per cent reduction (p=0.0389) in serum triglyceride levels at the end of 12 weeks. Total cholesterol, LDL cholesterol, HDL cholesterol, body weight and blood pressure remained unchanged relative to baseline in both the placebo and krill groups. No serious adverse side-effects were reported.
The researchers concluded that krill oil is a promising intervention for the reduction of triglyceride levels.The optimum daily dose and how its efficacy might compare to fish oil have yet to be determined.
Note: Krill oil should not be used in persons with shellfish allergy.
Source: Berge, Kjetil, et al. “Krill oil supplementation lowers serum triglycerides without increasing low-density lipoprotein cholesterol in adults with borderline high or high triglyceride levels.” Nutrition Research 34.2 (2014): 126-133.
© 2014 The Authors. Published by Elsevier Inc. Open access under CC BY-NC-ND license.
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Posted April 3, 2014.
References:
- Berge, Kjetl et al. Krill oil supplementation lowers serum triglycerides without increasing low-density lipoprotein cholesterol in adults with borderline high or high triglyceride levels, Nutrition Resesarch, vol. 34 (2014) P.126-133
- Assmann G. et al. New and classical risk factors- the Munster heart study (PROCAM). Eur J Med Res 1997: 2: 237-42.
- Assmann G, Schulte H, Funke H, von Eckardstein A. The emergence of triglycerides as a significant independent risk factor in coronary artery disease. Eur Heart J. 1998;19(suppl M):M8–M14.
- Ford E, Li C, Zhao G, et al. Hypertriglyceridemia and its pharmacologic treatment among US adults. Arch Intern Med. 2009;169:572-578.
- Shearer GC, et al. Fish oil- how does it reduce plasma triglycerides? Biochim Biophys Acta 1821: 2012: 843-51.
