Peanut and cardiovascular disease risk factors: A systematic review and meta-analysis

Several studies have been conducted on the effects of peanut consumption on cardiovascular diseases (CVD) risk factors. However, the findings are conflicting and appear inconsistent. The aim of this review is to summarize the findings on the effect of peanut consumption on the risk factors of CVDs. We used relevant keywords and searched through PubMed, Scopus and Web of Science for articles published studies up to November 2018. Randomized controlled trials (RCTs) were included in this meta-analysis. Random or fixed-effects meta-analysis method depending on the results of heterogeneity tests was used to estimate the effect size. Between-study heterogeneity was assessed by Q test and I-2 index. Subgroup analysis was conducted to find any excess relationship. Publication bias was checked by Egger's test and funnel plot. Quality of studies was assessed by the Cochrane criteria. According to the results of 13 RCTs, peanuts has no significant effect on weight (WMD: -0.11 kg, P = 0.773), waist circumference (WMD: -1.41 cm, P = 0.139), body mass index (WMD: -0.14 kg/m(2), P = 0.428), systolic and diastolic blood pressure (WMD: -0.09 mmHg, P = 0.939 and WMD: 0.60 mmHg, P = 0.652, respectively), low-density lipoprotein cholesterol (WMD: -3.31 mg/dl, P = 0.472), triglyceride (WMD: -7.59 mg/dl, P = 0.180), total cholesterol (WMD: 3.15 mg/dl, P = 0.171), fasting blood sugar (WMD: 0.57 mg/dl, P = 0.604) and serum insulin (WMD: -0.40, P = 0.582). Also, this meta-analysis showed that peanut had a positive significant effect on high-density lipoprotein cholesterol (HDL) (WMD: 2.72 mg/dl, P = 0.001). Peanuts consumption has a positive significant effect on HDL especially at the type of peanut oil, high-oleic peanut and peanut sprout and in healthy subjects and for consumption more than 12 weeks, while has no significant effect on other CVD risk factors.