Summary: In a small crossover trial in prediabetic adults, mulberry leaf and corn silk extracts inhibited carbohydrate-digesting enzymes in the laboratory but did not reduce post-meal glucose in the group overall; a benefit appeared only in the overweight subgroup when delivered in a specific milk matrix.
PICO Summary
| Element | Detail |
|---|---|
| Population | 11 prediabetic individuals; randomised crossover trial plus in-vitro enzyme assays, China. |
| Intervention | Mulberry leaf and corn silk extracts (with resistant dextrin) in lactose-hydrolysed or galacto-oligosaccharide (GOS) milk matrices. |
| Comparison | Pure milk and lactose-hydrolysed milk without extracts. |
| Outcome | The extracts inhibited α-amylase and α-glucosidase dose-dependently and synergistically in vitro. No significant differences in postprandial glucose were seen across interventions in the prediabetic group overall. In the overweight subgroup, GOS milk with the extracts significantly reduced 1-hour glucose (-0.84 mmol/L), peak glucose (-0.54), and glucose excursion (-0.62) versus pure milk. |
Mulberry leaf and corn silk extracts and post-meal glucose
RCT crossover · prediabetes · acute meal test
No effect on postprandial glucose in the prediabetic group overall. A reduction in 1-hour, peak and excursion glucose appeared only in the overweight subgroup with a GOS milk matrix, a hypothesis-generating finding in just 11 people.
Expert Commentary
This is an honest mechanism-to-human study whose most important feature is that the overall clinical result was negative, with the benefit confined to a subgroup. The in-vitro rationale is sound, since mulberry leaf contains iminosugars that inhibit α-glucosidase and the combination suppressed both digestive enzymes, but the leap from a test tube to a meal is exactly where many such agents falter, and here the prediabetic group as a whole showed no significant change in postprandial glucose. That the overweight subgroup did respond is biologically plausible, as those with more insulin resistance may have more exaggerated glucose excursions to blunt, but a subgroup finding in a crossover of just 11 people is hypothesis-generating rather than persuasive, and the dependence on a particular GOS milk matrix further narrows applicability. Can I use this with my patients? Not really, on this evidence. I would not recommend mulberry leaf or corn silk preparations to lower post-meal glucose, since the trial did not show an overall effect, while noting that increasing fibre and choosing lower-glycaemic meals achieves a similar physiological goal with better support, and that any future role would need confirmation in adequately powered trials.
References
Sun Y, Niu X, Wang Y, et al. Effects of mulberry leaf and corn silk extracts against α-amylase and α-glucosidase in vitro and on postprandial glucose in prediabetic individuals: a randomized crossover trial. Nutrients. 2025;17(21):3438. doi:10.3390/nu17213438