To our knowledge, this is the first clinical trial focusing on the effect of the ginger supplement on the clinical manifestation, evaluated as the length of hospital stays, of hospitalized individuals with COVID-19. A significant improvement in hospitalization time was observed in response to the ginger supplement. One possible explanation for the observed beneficial effect of the ginger supplement on the length of stay in study participants could be the ginger-derived exosomal micro-RNA, which has been demonstrated to inhibit lung inflammation caused by COVID-19 in both in vitro and in vivo studies [16].
Interestingly, when stratified by sex, only men benefited from the ginger supplement, whereas no intervention effect was detected in women. This result aligned with the observed differences in manifestation and severity of COVID-19 between men and women reported in previous studies [17, 18], while the underlying mechanism regarding the sex differences in immunopathogenesis needs further investigation, these studies implied a possible difference in the host immunity related to sex and suggesting the necessity of considering potential sex effect in future clinical studies. Besides, our subgroup analysis highlighted the importance of ginger supplement to older adults, where the hospitalization time could be shortened to less than half of their un-supplemented comparisons, which could effectively reduce the suffering and pain and improve the life quality of the elderly. Aging has been recognized as a critical risk factor for the severity and mortality of COVID-19 [19, 20], possibly due to age-related general decline in immune function. Therefore, the beneficial effect of the ginger supplement on the length of hospital stay could be less prominent in younger adults given their relatively quicker recovery compared to the elderly. Last but not the least, we explored the potential impact of pre-existing medical conditions when infected with COVID-19. While the participants with prior health issues tended to have longer hospital stays, supplementing with ginger significantly shortened the length of stay by about 40%, suggesting a strong protective effect of ginger supplement to this vulnerable group.
This study has several limitations. The primary outcome we focused on here is the length of stay in the hospital, it would be better to record other clinical symptoms of COVID-19 to evaluate the potential impact of ginger supplementation on other aspects of the clinical manifestation of COVID-19. Thus this study should be considered preliminary. Further, biological samples (such as blood) were not collected in the current study, and we cannot link the observed difference in hospitalization time to possible changes in the immune response. The future study thus could examine the circulating level of inflammatory biomarkers, and further investigate the underlying mechanism of the observed beneficial effect of the ginger supplement.
In conclusion, this preliminary study suggested that supplementing individuals with COVID-19 with ginger could be a cost-effective strategy in the future treatment of COVID-19, and emphasized the importance of implementing ginger supplementation to the target population to achieve the best outcomes.