Enhancing sulforaphane absorption and excretion in healthy men through the combined consumption of fresh broccoli sprouts and a glucoraphanin-rich powder.
Level 2 - randomized trial
Randomized crossover trial in humans
PubMed 21910945 · doi:10.1017/S0007114511004429
What was done
Four healthy men participated in a four-arm crossover study where each consumed four distinct test meals separated by a 1-week washout period. The test meals consisted of dry cereal and yogurt served with either fresh broccoli sprouts (equivalent to 70 μmol sulforaphane), a glucoraphanin-rich powder lacking myrosinase (equivalent to 120 μmol sulforaphane), both combined, or a control meal with neither. Sulforaphane metabolites were measured in blood and urine over 24 hours.
What was found
The 24-hour urinary recovery of sulforaphane-N-acetylcysteine was 65% following the combination meal, 60% following the sprout meal, and 24% following the glucoraphanin powder meal. Appearance of isothiocyanates in urine and plasma was delayed after consuming the glucoraphanin powder alone compared to sprout and combination meals. Combining fresh sprouts with the powder synergistically accelerated and enhanced early sulforaphane absorption.
Why it matters
Supplements containing glucoraphanin often lack the active enzyme myrosinase required to convert it to bioavailable sulforaphane. Adding a source of active myrosinase, such as fresh broccoli sprouts, substantially improves sulforaphane absorption from myrosinase-deficient supplements.
Limits
The sample size was extremely small (n = 4) and limited strictly to healthy men. The study assessed only acute 24-hour pharmacokinetic markers rather than long-term health or disease prevention outcomes.
Cited by
- supports Supplements that pair glucoraphanin with active myrosinase have higher conversion efficiency and require lower doses of glucoraphanin than formulations relying solely on gut microbiome myrosinase.