Levan is a commonly used dietary fiber of the fructans group. Its impact on health remains undetermined. This double blind controlled study aimed to investigate the effect of 8 weeks' daily consumption of 500 mL of natural orange juice enriched with 11.25 g of levan compared to the same amount of natural orange juice without levan on weight, gastrointestinal symptoms and metabolic profiles of 48 healthy volunteers. The statistical analyses compared between- and within-group findings at baseline, 4 weeks and study closure. The compared parameters were: weight, blood pressure, blood laboratory tests, daily number of defecations, scores of stool consistency, abdominal pain, bloating, gas, dyspepsia, vomiting and heartburn. Despite a higher fiber level recorded in the study group, there was no significant difference in the effect of the two kinds of juices on the studied parameters. Both juices decreased systolic and diastolic pressures, increased sodium level (within normal range), stool number, and bloating scores, and decreased gas scores. In conclusion, levan itself had no effect on weight, gastrointestinal symptoms or metabolic profile of healthy volunteers. Its possible effect on obese, hypertensive or hyperlipidemic patients should be investigated in further studies.
Keywords: dietary fibers; fructans; levan; orange juice.