The effects of saffron (Crocus sativus L.) on mental health parameters and C-reactive protein: A meta-analysis of randomized clinical trials

Bacicground: The findings of trials investigating the effects of saffron (Crocus sativus L.) supplementation on depression, anxiety, and C-reactive protein (CRP) are inconsistent. The current meta-analysis of randomized controlled trials (RCTs) was carried out to assess the effects of saffron (Crocus sativus L.) administration on mental health parameters and CRP levels. Methods: Two independent authors systematically searched online databases including EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science from inception until 30th July 2019. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of included trials. The heterogeneity among the included studies was assessed using Cochrane's Q test and I-square (I-2) statistic. Data were pooled using a random-effects model and weighted mean difference (WMD) was considered as the overall effect size. Results: Twenty one trials were included in this meta-analysis. Consumption of saffron resulted in a significant reduction in Beck Depression Inventory (BDI) (11 studies with 12 effect size) (WMD: -4.86; 95 % CI: -6.58, 3.14), Beck Anxiety Inventory (BAI) (5 studies) (WMD: -5.29; 95 % CI: -8.27, 2.31) and Pittsburgh Sleep Quality Index (PSQI) scores (3 studies with 4 effect size) (WMD: -2.22; 95 % CI: -2.73, 1.72). Saffron intake did not affect Hamilton Depression Rating Scale (HDRS-D), Hamilton Anxiety Rating Scale (HARS-A) scores and C-reactive protein (CRP) levels. Conclusions: This meta-analysis demonstrated that saffron intake significantly reduced BDI, BAI and PSQI scores, but did not affect HDRS-D, HARS-A scores and CRP levels.