This study was conducted to elucidate the effects of decaffeinated green coffee bean extract (GCE) on anthropometric indices, glycaemic control, blood pressure, lipid profile, insulin resistance and appetite in patients with the metabolic syndrome (Mets). Subjects were randomly allocated to consume 400 mg GCE or placebo capsules twice per d for 8 weeks. Both groups were advised to follow an energy balanced diet. After GCE supplementation, systolic blood pressure (SBP) significantly reduced compared with the placebo group (-13·76 (sd 8·48) v. -6·56 (sd 9·58) mmHg, P=0·01). Also, GCE treatment significantly reduced fasting blood glucose (FBS) (-5·15 (sd 60·22) v. 29·42 (sd 40·01) mg/dl (-0·28 (SD 3·34) v. 1·63 (SD 2·22) mmol/l); P=0·03) and homoeostatic model of assessment of insulin resistance in comparison to placebo (-1·41 (sd 3·33) v. 1·23 (sd 3·84), P=0·02). In addition, waist circumference (-2·40 (sd 2·54) v. -0·66 (sd 1·17) cm, P=0·009) and appetite score (-1·44 (sd 1·72) v. -0·2 (sd 1·32), P=0·01) of the individuals supplemented with GCE indicated a significant decline. Besides, weight and BMI reduction in the intervention group was almost twice as much as the placebo group; however, this discrepancy was marginally significant (weight: -2·08 (sd 2·11) v. -0·92 (sd 1·30) kg, P=0·05). No difference was observed in terms of glycated Hb (HbA1c) percentage and lipid profile parameters between the two groups. To sum up, GCE administration had an ameliorating effect on some of the Mets components such as high SBP, high FBS and Mets main aetiological factors including insulin resistance and abdominal obesity. Furthermore, GCE supplementation could reduce appetite level.

Diabetes mellitus is one of the most common and important metabolic diseases in human. Curcumin, which is a natural polyphenol found in turmeric, can be used in treatment of diabetes complications for its antidiabetic, anti‐inflammatory, and antioxidant properties. In this double‐blind randomized clinical trial, 44 patients with Type 2 diabetes randomly assigned to curcumin or placebo group. Patients consumed either 1,500‐mg curcumin or placebo daily for 10 weeks. Anthropometric measurements were measured at baseline and at the end of the study. Serum concentrations of triglyceride (TG), total cholesterol, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, high‐sensitivity C‐reactive protein, and adiponectin were determined after 12‐hr fasting at the beginning and end of study. The mean serum level of TG decreased in curcumin group compared with baseline (109 ± 36 vs. 124 ± 36; p < 0.05). At the end of study, the mean concentration of high‐sensitivity C‐reactive protein decreased in the curcumin group compared to the control (2.9 ± 2.9 vs. 3.4 ± 4.2; p < 0.05). The mean serum concentration of adiponectin increased (64 ± 3 vs. 63 ± 4; p < 0.05) in the treatment group compared with the placebo at the end of the study. The results of the current study indicate that curcumin consumption may reduce diabetes complications through decreasing TG level as well as indicators of inflammation.

Background Diabetes mellitus is a common metabolic disorders in human and affect a lot of people around the world. Curcumin is a component of turmeric and in many studies therapeutic effects such as anti-hypertensive, anti-hyperlipidemia, anti-hyperglycemia for this substance are shown. Aim The aim of this study was to investigate the effect of curcumin supplementation on anthropometric indices glycemic control and oxidative stress in overweight patients with type 2 diabetes. Materials and methods In this randomized, double-blind, placebo-controlled trial, 53 participants with type 2 diabetes were divided randomly into the experimental and control groups to receive either 1500 mg curcumin or placebo capsule three times in a day for 10 weeks. Result Supplementation with curcumin in type 2 diabetes compare to placebo causes a significant changes in mean weight (− 0.64 ± 0.22 vs. 0.19 ± 0.37 p < 0.05), body mass index (BMI) (0.3 ± 0.03 vs. 0.1 ± 0 p < 0.05), waist circumference (WC) (− 1.2 ± 0.4 vs. − 0.43 ± 0.11 p < 0.05) and fasting blood sugar (FBS) (− 7 ± 2 vs. 3 ± 0.2 p < 0.05) but did not show any difference for hemoglobin A1c (HbA1c), insulin, malondialdehyde (MDA), total antioxidant capacity (TAC), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and pancreatic B cell function (HOMA-B) at end of study. Conclusion This study indicated that daily administration of 1500 mg curcumin has positive effects in reducing fasting blood glucose and weight in patients with type 2 diabetes. Trial registration NCT02529982. Registered 19 August 2015, http://www.clinicaltrial.gov