Does Quinoa (Chenopodium quinoa) Consumption Improve Blood Glucose, Body Weight and Body Mass Index? A Systematic Review and Dose-Response Meta-Analysis of Clinical Trials

Background: Quinoa (Chenopodium quinoa) has a structure similar to whole grains and contains phytochemicals and dietary fiber. Hence, it is considered a food substance with a high nutritional value. Objective: The purpose of the present study was to assess the efficacy of quinoa in reducing fasting blood glucose (FBG), body weight (BW), and body mass index (BMI) in a meta-analysis of randomized clinical trials. Methods: A comprehensive search in ISI Web of Science, Scopus, and PubMed databases as well as Google Scholar, was conducted up to November 2022 to identify reports of randomized clinical trials that investigated the effect of quinoa on FBG, BW, and BMI. Results: Seven trials comprising 258 adults with mean ages of 31 to 64 years were included in this review. Studies used 15 to 50 grams of quinoa/per day as an intervention, and the intervention was between 28 to 180 days. In a dose-response analysis of FBG, there was significant evidence of a nonlinear association between intervention and FBG based on the quadratic model (P-value for nonlinearity= 0.027); hence, the slope of the curve increased when quinoa intake was nearly 25 g/day. In comparison between quinoa seed supplementation and placebo, our findings showed that quinoa seed supplementation did not have a significant effect on BMI (MD: -0.25; 95% CI: -0.98, 0.47; I2=0%, P=0.998) and BW (MD: -0.54; 95% CI: -3.05, 1.97; I2=0%, P=0.99), when compared with placebo. Evidence of publication bias was not found among the included studies. Conclusion: The present analysis revealed the beneficial effects of quinoa on the blood glucose level. Further studies on quinoa are needed to confirm these results.