Plasma choline, homocysteine and vitamin status in healthy adults supplemented with krill oil: a pilot study

Abstract

Plasma concentrations of metabolites along the choline oxidation and tryptophan degradation pathways have been linked to lifestyle diseases and dietary habits. This study aimed to investigate how krill oil, a source of ω-3 polyunsaturated fatty acids (PUFAs) with a high phosphatidylcholine content, affected these parameters. The pilot study was conducted as a 28 days intervention in 17 healthy volunteers (18–36 years), who received a supplement of 4.5 g krill oil per day, providing 833 mg ω-3 PUFAs, and 1750 mg phosphatidylcholine. Krill oil supplementation increased fasting plasma choline (+28.4%, p < .001), betaine (+26.6%, p < .001), dimethylglycine (+33.7%, p < .001) and sarcosine (+16.8%, p < .001), whereas no statistically significant changes were seen for plasma glycine, serine, methionine, total homocysteine, cysteine, cystathionine, methionine sulfoxide, folate, cobalamin, B₂-, B₃-, and B₆ vitamers, tryptophan, kynurenines, nicotinamide, vitamin A and vitamin E. In summary, krill oil supplementation influenced choline metabolite levels, but not plasma metabolites of the tryptophan-kynurenine-nicotinamide pathways and vitamins. These observations should be confirmed in a placebo-controlled trial, including an ω-3 PUFA supplement without phospholipids to explore the potential additive effects of the different active ingredients.

Keywords:

• Antarctic krill
• choline oxidation pathway
• dimethylglycine
• Euphausiacea
• fatty acids
• omega-3
• one-carbon metabolism
• phosphatidylcholines
• tryptophan-kynurenine pathway
• kynurenine

Acknowledgements

The authors wish to thank Kari Williams and Liv Kristine Øysaed for valuable technical assistance during the study.

Disclosure statement

Rimfrost AS employed I.B. and M.S.R. at the time of the study. No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Rimfrost AS; and Bergen Research Foundation.