Supplementation of the Diet by Exogenous Myrosinase via Mustard Seeds to Increase the Bioavailability of Sulforaphane in Healthy Human Subjects after the Consumption of Cooked Broccoli.
Level 2 - randomized trial
Randomized crossover trial in humans
PubMed 29806738 · doi:10.1002/mnfr.201700980
What was done
In a randomized crossover study, 12 healthy adults consumed 200 g of cooked broccoli alone and 200 g of cooked broccoli with 1 g of powdered brown mustard seed (a source of active myrosinase). Urine was collected for 24 hours following consumption, and the primary sulforaphane metabolite (sulforaphane N-acetyl-l-cysteine, or SF-NAC) was quantified using HPLC.
What was found
Ingesting cooked broccoli alone resulted in a mean 24-hour urinary excretion of 9.8 ± 5.1 μmol SF-NAC per gram creatinine. Ingesting cooked broccoli with 1 g of mustard powder increased mean urinary excretion to 44.7 ± 33.9 μmol SF-NAC per gram creatinine, representing an over fourfold increase in sulforaphane bioavailability.
Why it matters
Cooking denatures the endogenous plant enzyme myrosinase, substantially reducing sulforaphane formation from glucoraphanin. This trial demonstrates in vivo that adding a small amount of exogenous dietary myrosinase from mustard seed restores and enhances sulforaphane absorption from cooked cruciferous vegetables.
Limits
The sample size was small (12 subjects) with wide inter-individual variability in excretion (standard deviation of ±33.9 μmol/g creatinine in the intervention arm). The study only measured urinary excretion over 24 hours and did not evaluate clinical endpoints, different cooking methods, or varying doses of mustard powder.
Cited by
- context Adding one gram of mustard seed to cooked broccoli increases sulforaphane bioavailability by about 45%.