The effect of saffron (Crocus sativus L.) supplementation on blood pressure, and renal and liver function in patients with type 2 diabetes mellitus: A double-blinded, randomized clinical trial.

Microalbuminuria and hypertension are the risk factors for diabetic nephropathy, and increased levels of liver enzymes are prevalent among diabetic patients. The aim of this research was to examine the effects of Crocus sativus supplementation on nephropathy indices, liver enzymes, and blood pressure in patients with type 2 diabetes (T2D).

This placebo-controlled, randomized clinical trial was performed among 80 T2D patients. Subjects were randomly assigned to either Crocus sativus (n = 40) or placebo (n = 40) groups and treated with C. sativus and or placebo for 12 weeks, respectively. Alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), serum urea, creatinine, 24-hr urine albumin, systolic blood pressure (SBP), diastolic blood pressure (DBP), physical activity, and dietary intakes were measured and blood samples were taken at baseline and after the 12‑week intervention to assess the differences between the two groups.

C. sativus supplementation compared with the placebo resulted in a significant reduction of SBP (P<0.005). However, changes in other indices including liver enzymes, serum creatinine, serum urea, and 24-hr urine albumin, and DBP were not significantly different between the two groups (p>0.05). Also, no significant changes in dietary intakes and physical activity were seen between the two groups.

This report shows that daily supplementation with 100 mg C. sativus powder improved SBP. However, it did not considerably improve DBP, nephropathy indices and liver functions in T2D patients after 12 weeks of administration.