A new study suggests krill oil supplementation may increase markers of immune function in men and women after an acute bout of endurance exercise.
Researchers from the University of Aberdeen (Aberdeen, Scotland) have reported that krill oil supplementation may increase markers of immune function after a bout of acute exercise. The findings come from a new study published in PLoS One.
The study followed 19 men and 18 women (aged 25.8 +/- 5.3 years) who were randomly assigned to consume either 2 g per day of krill oil or a placebo for 6 weeks. Aker Biomarine (Oslo, Norway) provided the Superba krill oil capsules used in the study.
At the beginning and end of the supplementation period, all subjects participated in a maximal exercise test and cycling time trial to evaluate exercise performance and illicit an immune response. The cycling time trial included participants cycling at 70 revolutions per minute with workload increasing every minute until volitional exhaustion.
Blood samples were collected before both exercise trials, as well as immediately after, one hour after, and three hours after exercise. Researchers examined the blood for markers of immune function, including erythrocyte fatty acid composition, plasma IL-6 concentration, thiobarbituric acid reactive substances (TBARS) concentration, natural killer (NK) cell cytotoxic activity, and peripheral blood mononuclear cell (PBMC) production.
Krill oil supplementation did not appear to modify exercise performance among study participants, but the experimental group did show increased PBMC IL-2 production and NK cell cytotoxic activity three hours post-exercise compared with the placebo group. There were no observed differences observed between male and female participants, according to the researchers.
“The current study has demonstrated that NK cell cytotoxic activity and PBMC IL-2, but not other cytokines, are increased after krill oil supplementation,” wrote the researchers. “What remains to be established are the mechanisms through which n-3 PUFA [polyunsaturated fatty acid] supplementation results in these alterations.”
Stuart Gray, PhD, senior lecturer at the University of Aberdeen and coordinator of the study, says an earlier study of fish oil supplementation and the post-exercise immune response showed similar results. However, Gray says, the dose of krill oil eicosapentaenoic (EPA) and docosahexaenoic (DHA) omega-3 fatty acids in the more recent krill study was only a quarter of that used in the previous fish oil study to achieve those similar results.
"It remains to be proven if the different structural forms (omega-3 phospholipids from krill oil versus omega-3 triglycerides from fish oil) can explain the difference," says Gray.
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Da Boit M et al., “The effect of krill oil supplementation on exercise performance and markers of immune function,” PLoS One, vol. 10, no. 9 (September 2015): e0139174