Krill oil supplementation for knee pain: a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials

Knee pain is a major cause of disability worldwide, particularly among the elderly. Current treatments, including nonsteroidal anti-inflammatory drugs and analgesics, often lead to adverse effects. Krill oil is being explored as a potential alternative, however its efficacy in managing knee symptoms remains unclear.

MEDLINE, Embase, and Cochrane databases were searched until May 2024 for studies comparing krill oil and placebo in knee pain patients. Endpoints included knee pain, stiffness, physical function, and lipid profiles (HDL-C, LDL-C, triglycerides, and total cholesterol). A restricted maximum likelihood random-effects model with standardized mean differences (SMD) and 95% confidence intervals (CI) was used. A trial sequential analysis was conducted to evaluate further research implications.

We included five trials with 700 patients using krill oil for knee pain. Results showed no significant difference between krill oil and placebo for knee pain, knee stiffness, and lipid profiles. However, krill oil demonstrated a significant small effect in improving knee physical function (SMD -0.24, 95% CI [-0.41; -0.08], I² = 0%).Trial sequential analysis provided certainty that krill oil enhances knee physical function compared to placebo and indicated no improvement in knee pain, but the findings for knee stiffness need to be confirmed by further research.

This study found that krill oil supplementation did not significantly improve knee pain, stiffness, or lipid profile, although it may help knee physical function. Based on these findings, krill oil supplementation is not yet justified for knee pain.