Effects of Pistachio Nut Supplementation on Blood Glucose in Patients with Type 2 Diabetes: A Randomized Crossover Trial

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The Review of Diabetic Studies,2014,11,2,190-196.
Published:August 2014
Type:Original Article
Author(s) affiliations:

Mahmoud Parham1, Saeide Heidari2, Ashraf Khorramirad2, Mohammad Hozoori3, Fatemeh Hosseinzadeh4, Lida Bakhtyari5, and Jamshid Vafaeimanesh6

1Clinical Research Development Center, Qom University of Medical Sciences, Qom, IRAN.

2Faculty of Nursing and Midwifery, Qom University of Medical Sciences, Qom, IRAN.

3Nutritional Research Center, Qom University of Medical Sciences, Qom, IRAN.

4Qom University of Medical Sciences, Qom, IRAN. 


Background: Diabetes is a chronic, potentially debilitating, and often fatal disease. Dietary strategies to reduce postprandial glycemia are important in the prevention and treatment of diabetes. Nuts are rich in mono- and polyunsaturated fatty acids, which may reduce hyperglycemia and improve metabolism. OBJECTIVES: To evaluate the effectiveness of pistachio nut supplementation on glycemic and inflammatory measures in patients with type 2 diabetes. Methods: In this double-blind, randomized, placebocontrolled, crossover trial, 48 diabetic patients were equally assigned to groups A and B. Patients in group A received a snack of 25 g pistachio nuts twice a day for 12 weeks and group B received a control meal without nuts. After 12 weeks of intervention, the patients had an 8-week washout. Then the groups were displaced, and group B received the same amount of pistachios for 12 weeks. Results: With respect to the total change in variables over both phases, there was a marked decrease in HbA1c (-0.4%) and fasting blood glucose (FBG) concentrations (-16 mg/dl) in the pistachio group compared with the control group (p ≤ 0.001 for both). There was no overall significant change in BMI, blood pressure, HOMA-IR, and C-reactive protein (CRP) concentrations. Analysis of the two phases separately showed a decrease in FBG by 14 mg/dl and in HbA1c by 0.45% in the treatment group (A) after 12 weeks, while no significant differences were seen in group B (control group). In the second phase, FBG decreased from 151.36 ± 39.22 to 137.28 ± 28.65 mg/dl (-14 mg/dl) and HbA1c decreased from 7.42 ± 0.97 to 7.15 ± 0.68 mg/dl (-0.28%, p = 0.013 and p = 0.033, respectively) in the pistachio group (B). Pistachio consumption reduced systolic blood pressure (p = 0.007), BMI (p = 0.011), and CRP (p = 0.002) in patients from the treatment groups, but not insulin resistance. Conclusion: Dietary consumption of pistachio nuts as a snack has beneficial effects on glycemic control, blood pressure, obesity, and inflammation markers in diabetic patients.