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.

Nutritional, Functional, and Technological Characterization of a Novel Gluten- and Lactose-Free Yogurt-Style Snack Produced With Selected Lactic Acid Bacteria and Leguminosae Flours

Aiming at meeting consumers' requirements for healthy foods, dietary needs (vegetarianism, lactose- and gluten-free), as well as the nutrition recommendations of the Health Authorities in terms of protein, fibers and bioactive compounds, the present study proposes a novel yogurt-style snack made with plant-derived ingredients. The biotechnological protocol includes the fermentation of a thermal-treated blend of cereal and legume flours by the selected lactic acid bacteria (LAB) Lactoplantibacillus plantarum DSM33326 and Levilactobacillus brevis DSM33325. The yogurt-style snack was characterized by protein and fiber concentration of 3 and 4%, respectively, and a low-fat content. Compared to the unfermented control, the yogurt-style snack was characterized by a significant higher concentration of free amino acids and lower contents of the antinutritional factors, i.e., phytic acid, condensed tannins, saponins and raffinose (up to 90%) mainly due to the LAB metabolic activity. Hence, an in-vitro protein digestibility of 79% and improvements of all the nutritional indexes related to the quality of the protein fraction (e.g., GABA) were achieved at the end of fermentation. According to the Harvard Medical School recommendations, the novel snack can be potentially classified as low-glycemic index food (53%). Antioxidant properties of the fermented snack were also improved by means of increased the total phenol content and radical scavenging activity. High survival rate of the starter LAB and a commercial probiotic (added to the snack) was found through 30 days storage under refrigerated conditions. The biotechnological protocol to make the novel snack here proposed is suitable for the large-scale application in food industry, giving a platform product with a peculiar and appreciated sensory profile.