Clinical evidence on the effects of saffron (Crocus sativus L.) on cardiovascular risk factors: A systematic review meta-analysis

Cardiovascular disease is a one of most common causes of mortality around the world. This meta-analysis aims to summarize and conclude the clinical evidence regarding the use of saffron and its constituents, in particular crocin, on cardiovascular risk factors. A systematic review was conducted with PubMed, Scopus, Web of Science, Cochrane library and Google Scholar up to 24 May 2018. Randomized controlled trials (RCTs) that assessed the clinical effects of saffron and/or its constituents on blood lipid profile, glycemic parameters, blood pressure and anthropometric indices in human subjects were included. Eleven publication from ten studies comprising 622 participants included in quantitative analysis. Pooling of results showed significant effect of saffron on diastolic blood pressure (-1.24 mmHg; 95% CI: -1.51 to -0.96; I-2 = 0%), body weight (-1.29 kg; 95% CI: -2.14 to -0.44; I-2 = 70%) and waist circumstance (-1.68 cm; 95% CI: -3.31 to -0.04; I-2 = 51%). When subgroup analysis was performed based on quality of studies, a significant reduction in fasting plasma glucose levels was observed in subgroup with high quality studies (-10.14 mg/dl; 95% CI: -13.80 to -6.48; I-2 = 0%). Meta-analysis did not reveal any significant change in lipid profile, fasting insulin, systolic blood pressure and body mass index following saffron consumption. Present meta-analysis suggests that saffron might be beneficial in several outcomes related with cardiovascular disease. However, further RCTs with long term intervention with different dose of administration are needed.