Broccoli sprouts: An exceptionally rich source of inducers of enzymes that protect against chemical carcinogens
Level 5 - mechanism / opinion, no new human data
Preclinical laboratory and animal study (Level 5 by Oxford CEBM criteria).
OpenAlex W2025054234 · doi:10.1073/pnas.94.19.10367
What was done
Researchers quantified phase 2 enzyme-inducing glucosinolates (particularly glucoraphanin, the precursor of sulforaphane) in 3-day-old cruciferous sprouts versus mature plants. They developed an extraction protocol at -50 °C to prevent myrosinase hydrolysis and evaluated the chemoprotective effect of 3-day-old broccoli sprout extracts on dimethylbenz(a)anthracene (DMBA)-induced mammary tumorigenesis in rats.
What was found
Three-day-old broccoli and cauliflower sprouts contained 10- to 100-fold higher levels of glucoraphanin than mature plants. Sprout extracts reduced the incidence, multiplicity, and rate of development of mammary tumors in DMBA-treated rats, though exact quantitative figures for tumor endpoints were not reported in the abstract. Sprouts also contained negligible amounts of indole glucosinolates compared to mature broccoli.
Why it matters
This study identified 3-day-old broccoli sprouts as an exceptionally concentrated dietary source of phase 2 enzyme inducers, establishing a foundation for subsequent clinical and translational research into sulforaphane-based chemoprotection.
Limits
The findings are limited to plant analytical chemistry and a chemically induced rodent model, without direct human clinical data. The abstract does not report sample sizes, specific numerical tumor reduction rates, dosing comparisons, or statistical variance.
Cited by
- supports The discovery that broccoli sprouts and seeds contain rich concentrations of glucoraphanin was published in 1997.