Objective: Evaluation of the effect of a ginger extract (Zintona EC) on patients suffering from gonarthritis.
Material and methods: Twenty-nine patients (6 men and 23 women) with symptomatic gonarthritis (ACR criteria), in the age range 42-85 years, were included after randomization in a double blind, placebo controlled, crossover study of 6 months' duration. The treatment group was given a ginger extract (250 mg of Zingiberis Rhizoma per capsule, qid), while the placebo group received the same number of identical looking capsules per day. The crossover occurred after 3 months of therapy. Results were evaluated by a 100mm visual analog scale (VAS) of pain on movement and of handicap.
Results: Eight patients dropped out because of inefficacy, three from group 1 (ginger extract first) and five from group 2 (placebo first). One patient from group 1 and one from group 2 dropped out because of heartburn (while they were on ginger extract). Twenty patients completed the study period of 24 weeks and 19 that of 48 weeks follow-up. By the end of 24 weeks there was a highly statistically significant difference between the VAS of pain and handicap of the two groups (P<0.001). However, at crossover both groups showed a statistically significant decrease in VAS of pain on movement and of handicap, but the differences between the groups did not reach statistical significance.
Conclusions: Zintona EC was as effective as placebo during the first 3 months of the study, but at the end of 6 months, 3 months after crossover, the ginger extract group showed a significant superiority over the placebo group.