Vigorous exercise lowers immunity by decreasing the number of natural killer (NK) cells a person is producing. A recent study suggests that taking krill oil supplements may improve the immune function of healthy, exercising adults by increasing the activity of NK cells as well as increasing the production of IL-2 (which regulates the activity of immune cells) in the recovery period after exercise.
Participants in the study included 37 healthy men and women with an average age of 25.8 who were given two grams of krill oil or a placebo daily for six weeks. All of the participants performed a simulated cycling time trial at the onset and conclusion of the study.
The researchers found that the krill oil supplement was associated with a 75% and 21% increase in erythrocyte EPA and DHA levels, respectively, and a 27% increase in the Omega-3 Index. They also noted decreases in arachidonic and docosatetraenoic acid of 7% and 17%, respectively.
Finally, the researchers noted significant increases in the production of PBMC IL-2 and in NK cell activity in the krill oil group during the recovery period. Other cytokines were not affected.
The researchers did not note any effect on heart rate or oxygen consumption.
Researchers from the University of Glasgow conducted the study. It was published on September 25, 2015, in PLoS One.
Krill oil is rich in omega-3s, which have been linked to improved joint mobility, aiding your immune system, and helping with age-related macular degeneration. Previous studies suggest that krill oil may be superior to fish oil in raising omega-3 levels.