Mulberry leaf extract decreases digestion and absorption of starch in healthy subjects-A randomized, placebo-controlled, crossover study.
Level 2 - randomized trial
Individual randomized, single-blind, placebo-controlled crossover trial
PubMed 28501729 · doi:10.1016/j.advms.2017.03.002
What was done
In a single-blind, randomized, placebo-controlled crossover study, 25 healthy subjects aged 19–27 years consumed a test meal (50 g 13C-abundant cornflakes with 100 mL low-fat milk) with either mulberry leaf extract (standardized to 36 mg 1-deoxynojirimycin) or placebo. One week later, participants received the alternate intervention. Starch digestion and absorption were measured using a starch 13C breath test.
What was found
The cumulative percentage dose recovery of 13C was significantly lower in the mulberry leaf extract group than in the placebo group (median [quartiles]: 13.9% [9.9–17.4] vs. 17.2% [13.3–20.6]; p = 0.015). The decrease became statistically significant starting 120 minutes after meal ingestion.
Why it matters
This trial confirms in humans that acute mulberry leaf extract ingestion inhibits starch breakdown and absorption, providing mechanistic support for its potential role in managing postprandial glycemic spikes.
Limits
The study had a small sample size (n = 25) limited to young, healthy participants, so results cannot be directly generalized to individuals with diabetes or insulin resistance. Only a single meal challenge was tested, the study was single-blind rather than double-blind, and direct clinical endpoints (such as blood glucose, insulin, and gastrointestinal side effects) were not reported in the abstract.