Background: Ginger has been proposed as a complementary treatment for musculoskeletal pain. However, efficacy, type, and safety remains unclear.
Objectives: To determine the effectiveness of consumption or topical application of ginger for pain relief and knee function improvement in patients with knee osteoarthritis.
Study design: Systematic review with meta-analysis of randomized clinical trials.
Methods: An electronic search was performed on Medline, Central, CINAHL, PEDro, SPORTDiscus, and LILACS databases. The eligibility criteria for selecting studies included clinical trials that compared consumption and/or topical ginger with placebo or other interventions for the pain relief and knee function in patients with medical diagnosis of knee osteoarthritis.
Results: Seven clinical trials met the eligibility criteria, and for the quantitative synthesis, 4 studies were included. For the comparison capsules versus placebo, mean difference for pain was -7.88 mm; 95% confidence interval (CI), 11.92 to 3.85 (P = 0.00), and standard mean difference for knee function was -1.61 points; 95% CI, -4.30 to -1.09 (P = 0.24). For the comparison of topical ginger versus standard treatment, standard mean difference for pain was 0.79 mm; 95% CI, -1.97 to 0.39 (P = 0.19), and standard mean difference for knee function was -0.51 points; 95% CI, -1.15 to 0.13 (P = 0.12).
Limitations: The current evidence is heterogeneous and has a poor methodologic quality.
Conclusions: There is insufficient evidence to support the use of oral ginger compared with placebo in the pain relief and function improvement in patients with knee osteoarthritis. For other comparisons, no statistically significant differences were found.
Key words: Osteoarthritis, knee osteoarthritis, ginger, pain, randomized clinical trial, systematic review.