Summary: In a small crossover trial, a functional milk with mulberry leaf and corn silk extracts did not reduce postprandial glucose in prediabetic individuals overall, but in an overweight subgroup a galacto-oligosaccharide version lowered the one-hour peak and glucose excursion versus pure milk.
PICO Summary
| Element | Detail |
|---|---|
| Population | 11 prediabetic adults, including an overweight subgroup (crossover; plus in vitro enzyme assays). |
| Intervention | Mulberry leaf and corn silk extracts in milk matrices, notably galacto-oligosaccharide (GOS) milk. |
| Comparison | Pure milk, lactose-hydrolyzed milk, and lactose-hydrolyzed milk with extracts plus resistant dextrin. |
| Outcome | No significant difference in the overall group. In the overweight subgroup, GOS milk with extracts cut 1-hour glucose (-0.84 mmol/L), maximum glucose (-0.54 mmol/L), and 2-hour excursion (-0.62 mmol/L) versus pure milk. Extracts inhibited alpha-amylase and alpha-glucosidase in vitro. No adverse events. |
Mulberry leaf + corn silk milk for postprandial glucose
Randomized crossover · prediabetes · single meal
Only in the overweight subgroup did GOS milk with extracts lower postprandial glucose; the overall prediabetic group showed no significant benefit.
Expert Commentary
The mechanism is sound, mulberry leaf’s 1-deoxynojirimycin is a genuine alpha-glucosidase inhibitor much like acarbose, so I can believe these extracts blunt carbohydrate digestion, and the in vitro enzyme data support that. But I have to read the human results as they actually fell, not as the title implies. In the overall prediabetic group there was no significant effect; the benefit appeared only in an overweight subgroup, in one specific milk matrix, among eleven people across multiple comparator drinks. That is a lot of subgroup and multiple-comparison territory for a positive finding, and it is exactly the setting where chance produces apparent effects. The endpoints are also single-meal surrogates with no HbA1c and nothing on progression. Can I use this with my patients? Not as a recommendation. It is a plausible, well-tolerated idea that might one day complement lifestyle measures, but on a tiny subgroup result I would not advise anyone to buy a functional milk for glucose control. Lifestyle change and, where indicated, metformin remain the substance. I would want a larger trial powered in the whole population before saying more.
References
Sun Y, Niu X, Wang Y, et al. Effects of mulberry leaf and corn silk extracts against alpha-amylase and alpha-glucosidase in vitro and on postprandial glucose in prediabetic individuals: a randomized crossover trial. Nutrients. 2025;17(21):3438. doi:10.3390/nu17213438