The peel of jaboticaba is a source of cyanidin 3-glucoside, ellagitannins, and dietary fibers, pointed out as bioactive compounds counteracting the effect of high-fat diets. A non-clinical trial proved better cognitive performance when 4% jaboticaba peel powder was added to a high-fat diet. In this study, a long-term clinical trial investigated whether similar effects could also be observed in human subjects when jaboticaba peel powder was given to healthy subjects. Nineteen healthy adults (8 men; 11 women; average age 27.5 years) completed a 4-week randomized, controlled, crossover trial with 28 days washout period. Participants were randomized to consume powdered freeze-dried jaboticaba peel or control (sugar and cellulose), both blended in water. On days 1 and 28 of the trial, blood samples were collected at fasting for up to 180 min after treatments and a breakfast challenge with a standardized amount of white bread. The treatment with jaboticaba peel did not change postprandial glucose, insulin, adiponectin, and non-esterified fatty acid levels (p>0.05). Fasting and postprandial levels of IL-6 were about 30 to 40% lower after treatment with jaboticaba peel (p<0.05). Malondialdehyde production was also 9% lower postprandially (p<0.01). The 28 days-intervention with jaboticaba peel improved by about 10% appetite (p<0.05). In some aspects, a better cognitive performance was also shown after performing a computerized selective attention test (p<0.05). This study corroborates data from non-clinical studies and suggests the benefit of a diet containing jaboticaba peel in human subjects.