Mulberry leaf extract reduces the glycemic indexes of four common dietary carbohydrates.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 30142838 · doi:10.1097/MD.0000000000011996
What was done
A single-center, randomized, open-label, 7-cycle self-controlled crossover study evaluated 15 healthy volunteers. Over 7 visits separated by 3-day intervals, participants orally consumed reference glucose (tested on 3 separate occasions), glucose + mulberry leaf extract (MLE), sucrose + MLE, maltose + MLE, and maltodextrin + MLE. Blood glucose levels were measured at baseline (-15 min) and at 15, 30, 45, 60, 90, and 120 minutes post-ingestion. Glycemic index (GI) was calculated using the incremental area under the curve relative to glucose (defined as GI = 100). Safety was monitored at each visit.
What was found
All 15 participants completed the study. Blood glucose peaked at 30 minutes for glucose, glucose + MLE, sucrose + MLE, and maltose + MLE, and at 45 minutes for maltodextrin + MLE. At 30 minutes, the change in blood glucose was significantly lower for sucrose + MLE, maltose + MLE, and maltodextrin + MLE compared with glucose or glucose + MLE (P < .05). Calculated GIs were: - Sucrose + MLE: 43.22 ± 17.47 - Maltose + MLE: 49.23 ± 22.39 - Maltodextrin + MLE: 75.90 ± 26.01 - Glucose + MLE: 91.88 ± 27.24 Relative to standard reference values, MLE reduced the GIs of maltose by 53.11%, sucrose by 33.51%, maltodextrin by 31.00%, and glucose by 8.12%. MLE was well tolerated.
Why it matters
Co-ingestion of mulberry leaf extract selectively lowers the acute glycemic response to disaccharides and oligosaccharides requiring alpha-glucosidase cleavage, with minimal effect on monosaccharide (glucose) absorption.
Limits
The trial had a very small sample size (n = 15) and included only healthy volunteers, precluding direct extrapolation to populations with impaired glucose tolerance or diabetes. The design was open-label, tested only acute 2-hour responses without measuring insulin or incretin dynamics, and the abstract omitted specific extract and carbohydrate doses.
Cited by
- supports Maltodextrin produces a greater glycemic response than sucrose.