Acute Effects of Apple Cider Vinegar on Postprandial Glycemia Following a High-Carbohydrate Meal in Healthy Adults: A Randomized Placebo-Controlled Trial

Background and Aim: Vinegar consumption has been suggested to attenuate postprandialglycemic responses; however, evidence from studies using high-carbohydrate meals inhealthy adults remains limited. This study aimed to evaluate the acute effects of apple cidervinegar consumed with a high-carbohydrate test meal on postprandial glycemia (PPG) andthe net incremental area under the glucose response curve (net iAUC) in healthy adults.Methods: This single-blind, randomized, parallel-group, placebo-controlled trial included 36healthy adults aged 18–50 years. Participants were randomly assigned to either theintervention group (n = 18) or the control group (n = 18). All participants consumed astandardized test meal containing approximately 93 g of carbohydrates. The interventiongroup received a beverage containing 20 mL of apple cider vinegar together with the meal,whereas the control group received a placebo beverage. Capillary blood glucoseconcentrations were measured in the fasting state and at 30, 45, 60, and 120 min after mealconsumption. Net iAUC values were calculated using the trapezoidal method. Postprandialglucose concentrations were analyzed using a linear mixed model with Bonferroni-adjustedpairwise comparisons, and net iAUC was compared using analysis of covariance adjusted forbaseline fasting glucose.Results: No significant differences were observed between groups regarding age, body massindex, or other baseline characteristics (p > 0.05). Fasting, 30-min, 45-min, and 120-minglucose concentrations did not differ significantly between groups (p > 0.05). However, theblood glucose concentration at 60 min was significantly lower in the intervention group thanin the control group (109.94 ± 20.43 vs 123.83 ± 19.92 mg/dL; adjusted p = 0.045). Althoughnet iAUC was approximately 25% lower in the intervention group than in the control group(2841.67 ± 1703.84 vs 3804.58 ± 1806.49 mg × min/dL), this difference was not statisticallysignificant after adjustment for baseline fasting glucose (p = 0.108). The overall group × timeinteraction was not statistically significant (p = 0.288).Conclusions: Apple cider vinegar may reduce blood glucose concentrations during the earlypostprandial period following a high-carbohydrate meal in healthy adults. Nevertheless, nostatistically significant effect was observed on net iAUC or the overall two-hour glucoseresponse. Larger studies with robust methodological designs, or studies that provide it beforea meal, are needed to further clarify the acute effects of apple cider vinegar on PPG.