Effects of dietary supplementation with krill meal on serum pro-inflammatory markers after the Iditarod sled dog race

A seafood-based supplement from krill, rich in omega-3 phospholipids and proteins was tested on a group of dogs competing in the 2016 Iditarod dog sled race to investigate the effects of krill meal on exercise-induced inflammation and muscle damage in comparison to a control group. A single team of 16 dogs received 8% krill meal for 5 weeks prior to the start of race, while another team of 16 dogs received no supplementation. Ten dogs of the treatment and 11 dogs of the control group finished the race and their blood was analyzed for omega-3 index, inflammation (CRP) and muscle damage (CK). The omega-3 index of the krill meal-fed dogs was significantly higher at the beginning of the race (mean 6.2% in the supplemented vs 5.2% in the control group, p <.001). CRP concentrations increased from 7.05 ± 2.27 to 37.04 ± 9.16 μg/ml in the control and from 4.26 ± 0.69 to 16.56 ± 3.03 μg/ml in the treatment group, with a significant difference between the groups (p <.001). CK activity was increased from 90.75 ± 8.15 IU/l to 715.90 ± 218.9 IU/l in the control group and from 99.55 ± 12.15 to 515.69 ± 98.98 in the supplemented group, but there were no differences between groups (p =.266). The results showed that krill meal supplementation led to significantly higher omega-3 index, which correlated with lower inflammation and a tendency for reduced muscle damage after this long-distance sled dog competition. However, these results need to be confirmed by more controlled studies, since it was a field study and effects of race speed or other performance-related factors such as fitness and musher skill on the results cannot be excluded.