Effectiveness of Ginger on Pain and Function in Knee Osteoarthritis: A PRISMA Systematic Review and Meta-Analysis

Araya-Quintanilla F, Gutiérrez-Espinoza H, Muñoz-Yañez MJ, Sánchez-Montoya U, López-Jeldes J · Pain Physician

Reaches the opposite conclusion to the 2015 meta-analysis on overlapping trials, without contradicting its pain estimate. Capsules versus placebo gave a mean pain difference of −7.88 mm at one month, p = 0.0001, with no heterogeneity between the four pooled trials (I² = 0%). Knee function did not separate: standardized mean difference −1.61, p = 0.24, with I² = 99%. Topical ginger against standard treatment was non-significant for both pain (p = 0.19) and function (p = 0.12). The authors describe that pain result as a minimal effect confined to the pain domain of WOMAC, conclude there is insufficient evidence to support oral ginger over placebo, and describe the evidence base as heterogeneous and of poor methodological quality.

Population

Seven clinical trials meeting eligibility, four pooled, of oral or topical ginger in knee osteoarthritis

Intervention

Ginger capsules or topical ginger

Comparator

Placebo or standard treatment

Limitations

Only four of seven eligible trials were poolable, and publication bias could not be assessed at that number. The abstract and the results section disagree on two of the confidence intervals — the pain interval is printed as '11.92 to 3.85' in the abstract and '−11.92 to 3.85' in the results, and the function interval as '−4.30 to −1.09' against '−4.30 to 1.09', with only the results version consistent with the p = 0.24 beside it. The authors name unclear randomisation, unconcealed allocation and unblinded assessors among the included trials, and abandoned their planned subgroup analyses because the trials did not report stratified results. No external funding; no author declares a commercial association.