Effects of a hydroalcoholic extract of Juglans regia (walnut) leaves on blood glucose and major cardiovascular risk factors in type 2 diabetic patients: a double-blind, placebo-controlled clinical trial.

BMC Complement Altern Med. 2018 Jul 4;18(1):206. doi: 10.1186/s12906-018-2268-8. Rabiei K1, Ebrahimzadeh MA2, Saeedi M2, Bahar A3, Akha O3, Kashi Z4,5. Author information 1 World Federation of Acupunture-Moxibustion Societies (WFAS), Scientific Studies Institute of Nadali Esmaeili, Acupuncture Center, Sari, Iran. 2 Pharmaceutical Sciences Research Center, Hemoglobinopathy Institute, Mazandaran University of Medical Sciences, Sari, Iran. 3 Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran. 4 Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran. kashi_zahra@yahoo.com. 5 Traditional and Complementary Medicine Research Center, Addiction Institute, Mazandaran University of Medical Sciences, Sari, Iran. kashi_zahra@yahoo.com. Abstract BACKGROUND: We aimed to evaluate the effects of a hydroalcoholic extract of Juglans regia L. leaves on blood glucose level and cardiovascular risk factors in type 2 diabetic patients. METHODS: In this randomized, double-blind, placebo-controlled, parallel-group (2 arms) clinical trial, 50 diabetic patients were divided into two groups: treatment group (receive the capsules containing 100 mg J. regia leaf extract) and control group (receive the capsules containing placebo, microcrystallin cellulose). Baseline participant data were matched between the two arms of the study. We administered the prepared capsules to the patients twice daily for 8 weeks. Blood glucose level, glycosylated hemoglobin (HbA1c) level, body weight, body mass index, blood pressure, lipid profile, serum insulin, and insulin resistance were compared between the two groups before and after the intervention. P < 0.05 was considered significant. RESULTS: After excluding eleven patients, 20 received J. regia leaf extract and 20 patients received placebo. The J. regia leaf extract did not significantly change the blood glucose and insulin resistance condition. However, in this group, body weight, body mass index, and systolic blood pressure significantly decreased compared with the baseline measurements (P = 0.028, P = 0.030, and P = 0.005, respectively). The lipid profile did not change significantly compared with the baseline measurements. In the control group, postprandial glucose and HbA1c levels significantly decreased after the intervention (P = 0.030 and P = 0.028, respectively). The other variables were not significantly different in this group. At the end of the study, the variables were not significantly different between the two groups. CONCLUSION: In this double-blind study, 200 mg/d of J. regia leaf extract had no significant effect on blood glucose level and HOMA-IR score in patients with type 2 diabetes. However, the J. regia leaf extract was effective in reducing body weight and blood pressure. An accidental finding of our study was that microcrystalline cellulose, a widely used placebo in clinical trials, led to a reduction in blood glucose level. TRIAL REGISTRATION: Iranian Registry of Clinical Trials (IRCT: 138901203180 N2 , 2010/6/6); retrospectively registered. KEYWORDS: Avicel; Blood glucose; Blood pressure; Cardiovascular; Diabetes mellitus; Herbal medicine; Juglans regia; Microcrystalline cellulose; Walnut leaves; Weight PMID: 29973195 PMCID: PMC6031195 DOI: 10.1186/s12906-018-2268-8 Free PMC Article