OBJECTIVE: To evaluate the effects on healthy subjects of locally produced cane vinegar on the postprandial glucose surge after ingestion of a vinegar-containing meal. METHODOLOGY: A randomized controlled study on 37 healthy adult subjects with normal BMI. Subjects were randomized to a standard meal containing 28 mmols of acetic acid in the form of locally produced cane vinegar or to a meal without vinegar. The study was conducted for seven days, with all the volunteer subjects having the standard meals every morning. FBS and plasma insulin were determined on the first and last day of the study trial. Plasma glucose was also determined 30, 60 and 120 minutes after breakfast on all days of the trial. The postprandial plasma glucose results were compared between groups and across the seven days of observation using factorial analysis of variance (ANOVA). RESULTS: A total of 49 people were enrolled in the study but 12 were considered drop-outs. Volunteers who received vinegar had significantly lower blood glucose levels than those without vinegar, which was noted at 30 minutes postprandial (mean difference 16.68 mg/dl, p=0.005) and at 1 hour postprandial, (mean difference=12.2, p=0.02). Insulin levels did not statistically differ between the two groups. CONCLUSION: The mean drop in blood glucose values at 30 minutes and 1-hour postprandial were significantly higher in the vinegar meal group than in the control group.