Effects of pistachios on anthropometric indices, inflammatory markers, endothelial function and blood pressure in adults: a systematic review and meta-analysis of randomised controlled trials

Abstract

Evidence suggests that eating nuts may reduce the risk of CVD. This study was intended to pool the data of all randomised controlled trials (RCT) available to determine if pistachios confer a beneficial effect on anthropometric indices, inflammatory markers, endothelial dysfunction and blood pressure. Without language restriction, PubMed, Scopus, Cochrane Library and Web of Science were searched for articles published from the earliest records to June 2019 investigating the effect of pistachio consumption on inflammation, endothelial dysfunction and hypertension. Mean difference (MD) was pooled using a random effects model. The Cochrane risk of bias tool was used to evaluate the quality of the studies. The meta-analysis of thirteen RCT with 563 participants indicated that pistachio consumption significantly decreased systolic blood pressure (SBP) (MD: -2·12 mmHg, 95 CI -3·65, -0·59, P = 0·007), whereas changes in flow-mediated dilation (MD: 0·94 , 95 CI -0·99, 2·86, P = 0·813), diastolic blood pressure (MD: 0·32 mmHg, 95 CI -1·37, 2·02, P = 0·707), C-reactive protein (MD: 0·00 mg/l, 95 CI -0·21, 0·23, P = 0·942), TNF-α (MD: -0·09 pg/ml, 95 CI -0·38, 0·20, P = 0·541), body weight (MD: 0·09 kg, 95 CI -0·38, 0·69, P = 0·697), BMI (MD: 0·07 kg/m2, 95 CI -0·16, 0·31, P = 0·553) and waist circumference (MD: 0·77 cm, 95 CI -0·09, 1·64, P = 0·140) were not statistically significant. This systematic review and meta-analysis suggested the efficacy of pistachio consumption to reduce SBP levels. However, further large-scale studies are needed to confirm these results.