Effects of pistachios on glycaemic control: a systematic review and meta-analysis of randomised controlled trials

To evaluate the effects of pistachio consumption on the glucoregulatory status in individuals with a high risk of CVD, a systematic review and meta-analysis of randomised controlled trials (RCT) were conducted. Online databases including PubMed, Scopus, Web of Science and Cochrane Library were searched from inception until June 2019. Human trials that reported data for fasting blood sugar (FBS), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were included. Data were pooled using the random effect models and expressed as weighted mean difference (WMD) with 95 % CI. Eight RCTs were included in the analyses. Pistachio consumption, exchanged isocalorically for other foods, decreased FBS (WMD: -5 center dot 32 mg/dl, 95 % CI (-7 center dot 80, -2 center dot 64), P < 0 center dot 001) and insulin (WMD: -1 center dot 86 mu IU/ml, 95 % CI (-3 center dot 13, -0 center dot 59), P < 0 center dot 01) concentrations in individuals with a high risk of CVD. However, no changes were observed in the levels of HOMA-IR between the groups (WMD: -0 center dot 66, 95 % CI (-1 center dot 89, 0 center dot 58), P = 0 center dot 30). Pistachio consumption may improve glucoregulatory status in individuals at risk for CVD, as evidenced by reduced FBS and insulin concentrations. However, due to the limited availability of studies with diabetic cases and relatively small sample sizes of available studies, well-designed trials with adequate sample sizes aimed at diabetic populations are recommended.