The effect of krill oil supplementation on skeletal muscle function and size in older adults: A randomised controlled trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 35504165 · doi:10.1016/j.clnu.2022.04.007
What was done
A double-blind randomized controlled trial (NCT04048096) investigated the effects of krill oil supplementation (4 g/day) versus a control for 6 months in healthy older adults (age >65 years, BMI <35 kg/m2, <1 h/week structured exercise). A total of 102 participants were enrolled and 94 completed the trial (krill group: 26 women, 23 men; placebo group: 27 women, 18 men; mean age 71.2 years). Knee extensor maximal torque was measured at baseline, 6 weeks, and 6 months as the primary outcome. Secondary outcomes included grip strength, vastus lateralis muscle thickness, Short Physical Performance Battery (SPPB), body composition, neuromuscular parameters (M-Wave, RMS, voluntary activation), blood metabolic/inflammatory markers, and erythrocyte fatty acid profile.
What was found
Relative to control, 6 months of krill oil supplementation significantly increased knee extensor maximal torque by 9.3% (95% CI: 2.8, 15.8%), grip strength by 10.9% (95% CI: 8.3, 13.6%), and vastus lateralis muscle thickness by 3.5% (95% CI: 2.1, 4.9%) (all p<0.05). Erythrocyte EPA increased by 214% (95% CI: 166, 262%), DHA by 36% (95% CI: 24, 48%), and omega-3 index by 61% (95% CI: 49, 73%). M-Wave increased by 17% (95% CI: 12.7, 38.1%, p<0.05). There was no significant effect on RMS, voluntary activation, SPPB scores, body fat, overall muscle mass, blood lipids, glucose, insulin, CRP, or quality of life.
Why it matters
This trial shows that high-dose krill oil can modestly improve isolated muscle strength and regional muscle thickness in older adults without concurrent exercise training.
Limits
The trial evaluated a relatively small cohort of 94 healthy, sedentary completers. Functional mobility measured by SPPB and total muscle mass did not improve, and the abstract does not describe the specific composition of the control supplement.
Cited by
- supports Krill oil supplementation has been shown to increase muscle strength or size in older adults.
- supports Stuart Gray published a study using krill oil that replicated the muscle mass and strength findings seen with fish oil supplementation.
- supports Stuart Gray published a study using krill oil supplementation that replicated findings of enhanced muscle mass and strength in a similar cohort over a similar duration.