CATEGORIES
TAGS
The Myrosinase Factor: Why Most Supplements Fall Short
When it comes to sulforaphane bioavailability, there's one enzyme that makes all the difference: myrosinase. This plant enzyme is responsible for converting glucoraphanin (the precursor compound) into bioactive sulforaphane. Here's where most commercial supplements run into trouble.
"The bioavailability of sulforaphane from supplements is dramatically lower than from fresh broccoli sprouts, primarily due to the absence of active myrosinase enzyme." - Dr. Jed Fahey, Johns Hopkins School of Medicine
Fresh broccoli sprouts contain both glucoraphanin and active myrosinase in the same plant cells. When you chew the sprouts, cell walls break down, allowing these compounds to interact and produce sulforaphane in real-time. Most commercial supplements, however, undergo processing that destroys or removes the myrosinase enzyme.
The Numbers Don't Lie: Bioavailability Comparison
Clinical studies have revealed striking differences in sulforaphane absorption:
Fresh broccoli sprouts: 3-4x higher bioavailability compared to standard supplements
Standard glucoraphanin supplements: Rely entirely on gut bacteria for conversion (highly variable)
Myrosinase-enhanced supplements: Can approach sprout-level bioavailability when properly formulated
A landmark study by Clarke et al. found that participants consuming fresh broccoli sprouts showed significantly higher urinary sulforaphane metabolites compared to those taking equivalent doses of glucoraphanin supplements without myrosinase.
Why Your Gut Bacteria Aren't Enough
Some supplement manufacturers argue that gut bacteria can convert glucoraphanin to sulforaphane, making myrosinase unnecessary. While this conversion can occur, it's highly unreliable:
Individual variation: Gut microbiome composition varies dramatically between people
Antibiotic impact: Recent antibiotic use can severely reduce conversion capacity
Efficiency: Even optimal gut bacteria convert only a fraction compared to plant myrosinase
Research indicates that only about 10-30% of people have sufficient gut bacteria to meaningfully convert glucoraphanin without plant-derived myrosinase.
The Fresh Sprout Advantage
Beyond bioavailability, fresh broccoli sprouts offer additional benefits:
Optimal Timing
Sulforaphane formation occurs immediately upon chewing, ensuring maximum potency. In contrast, supplements may lose potency during storage or fail to convert effectively in the digestive system.
Synergistic Compounds
Sprouts contain other beneficial compounds like vitamin C, folate, and additional glucosinolates that may enhance sulforaphane's effects through synergistic mechanisms.
Cost Effectiveness
Growing your own sprouts costs pennies per serving compared to premium supplements, which can cost $1-3 per equivalent dose.
When Supplements Make Sense
Despite the advantages of fresh sprouts, supplements can be appropriate in certain situations:
Travel and convenience: When fresh sprouts aren't practical
Standardized dosing: For research or therapeutic protocols requiring precise amounts
Taste preferences: Some people find sprouts too peppery or bitter
If choosing supplements, look for products that:
Include active myrosinase enzyme
Use enteric coating to protect compounds from stomach acid
Provide third-party testing for sulforaphane yield
Store properly (refrigerated when possible)
Practical Recommendations for Health Optimization
For Maximum Bioavailability
Choose fresh sprouts when possible - grow your own or buy from reputable sources
Chew thoroughly to maximize enzyme contact
Consume quickly after harvesting or purchasing
Consider timing - some research suggests consuming with a small amount of fat may enhance absorption
Supplement Selection Criteria
If supplements are necessary, prioritize products that explicitly include myrosinase and provide bioavailability data. Avoid products that only list glucoraphanin content without addressing conversion.
The Bottom Line
While the supplement industry has made strides in sulforaphane delivery, fresh broccoli sprouts remain the gold standard for bioavailability. The combination of glucoraphanin and active myrosinase in their natural matrix provides optimal conditions for sulforaphane formation and absorption.
For those serious about maximizing sulforaphane intake, incorporating fresh sprouts into your routine 3-4 times per week provides more reliable and cost-effective results than most commercial supplements. When supplements are necessary, choose products that acknowledge and address the myrosinase factor rather than relying solely on gut bacteria conversion.
Future Research Directions
Ongoing research is exploring:
Optimal timing and dosing protocols for both sprouts and supplements
Individual genetic factors affecting sulforaphane metabolism
Combination therapies with other bioactive compounds
Novel delivery systems for enhanced bioavailability
As our understanding of sulforaphane pharmacokinetics improves, we may see more sophisticated supplement formulations that better mimic the natural sprout delivery system.
References
Clarke, J.D., et al. (2011). "Comparison of isothiocyanate metabolite levels and histone deacetylase activity in human subjects consuming broccoli sprouts or broccoli supplement." Journal of Agricultural and Food Chemistry, 59(20), 10955-10963.
Fahey, J.W., et al. (2015). "Sulforaphane bioavailability from glucoraphanin-rich broccoli: control by active endogenous myrosinase." PLoS One, 10(11), e0140963.
Cramer, J.M., et al. (2012). "Loading and retention of sulforaphane in human erythrocytes." Molecular Nutrition & Food Research, 56(7), 1196-1202.
Oliviero, T., et al. (2018). "In vivo formation and bioavailability of isothiocyanates from glucosinolates in broccoli: effects of processing conditions." Molecular Nutrition & Food Research, 62(14), 1700447