What vegetable has the most sulforaphane? The surprising answer for a healthy diet

October 4, 2025 •

2 min read

Did you know that broccoli sprouts can contain up to 100 times more glucoraphanin, the precursor to sulforaphane, than mature broccoli? This fact makes the answer to the question, what vegetable has the most sulforaphane?, clear and surprising to many who believe mature broccoli is the best source.

Quick Summary

Broccoli sprouts are the richest natural source of sulforaphane, containing significantly higher levels of the precursor compounds than mature broccoli. Maximizing this potent antioxidant requires specific preparation techniques to activate the crucial myrosinase enzyme.

Key Points

Broccoli Sprouts are King: Broccoli sprouts contain up to 100 times more glucoraphanin (the sulforaphane precursor) than mature broccoli, making them the richest source.
Precursor Activation is Key: Sulforaphane is formed when glucoraphanin and the enzyme myrosinase mix, typically when the vegetable is chopped or chewed.
Preparation Matters: To maximize sulforaphane, chop cruciferous vegetables and let them sit for 40 minutes before cooking, or consume them raw.
Avoid High-Heat Cooking: Boiling and microwaving can destroy the heat-sensitive myrosinase enzyme. Opt for gentle steaming or sautéing.
Use the 'Mustard Trick': Adding mustard seed powder to cooked cruciferous vegetables restores myrosinase activity, boosting sulforaphane levels.
Harness Antioxidant Power: Sulforaphane activates the body's natural defense systems to reduce inflammation and protect cells from oxidative stress.
Benefit from Detoxification: Sulforaphane supports the liver's ability to eliminate toxins and other harmful compounds from the body.

The Science Behind Sulforaphane: Glucoraphanin and Myrosinase

Sulforaphane is a potent isothiocyanate known for its antioxidant, anti-inflammatory, and detoxification properties. It is formed when glucoraphanin and the enzyme myrosinase come together, usually when a vegetable is cut or chewed. This reaction is essential for creating active sulforaphane from its precursors found in cruciferous vegetables. To get the most sulforaphane, you need both high levels of glucoraphanin and active myrosinase.

The Undisputed King: Broccoli Sprouts

Broccoli sprouts are the top source when considering what vegetable has the most sulforaphane. These young sprouts contain significantly more glucoraphanin than mature broccoli, offering 20 to 100 times the potential sulforaphane.

Comparing Sulforaphane Content in Cruciferous Vegetables

While broccoli sprouts are the richest source, other cruciferous vegetables also provide sulforaphane precursors. The following table compares the typical potential sulforaphane content.


Feature	Broccoli Sprouts	Mature Broccoli	Cabbage (Green)	Brussels Sprouts
Sulforaphane Potential	Very High (20-100x mature broccoli)	Low to Moderate	Moderate	Moderate
Key Precursor	Very High in Glucoraphanin	Lower in Glucoraphanin	High in Glucoraphanin	Moderate in Glucoraphanin
Enzyme Activity	High Myrosinase Activity (Raw)	Lower Myrosinase Activity (Raw)	Standard Myrosinase Activity (Raw)	Standard Myrosinase Activity (Raw)
Taste Profile	Mild, slightly peppery	Earthy, typical broccoli flavor	Versatile, mild flavor	Strong, pungent flavor

Maximizing Sulforaphane Bioavailability in Your Kitchen

Proper preparation is crucial to get the full benefits of sulforaphane because the myrosinase enzyme is sensitive to heat.

Follow these tips to enhance sulforaphane availability:

Chop and Wait: Chop raw cruciferous vegetables and let them sit for at least 40 minutes before cooking. This resting period allows myrosinase to work before heat can destroy it.
Use Gentle Cooking: Steam or quickly sauté vegetables instead of boiling or microwaving to preserve the myrosinase enzyme.
Add Mustard Seed Powder: If you cook at high heat, add a pinch of mustard seed powder after cooking. It contains myrosinase and can help activate sulforaphane.
Combine Raw and Cooked: Add raw sprouts or shredded raw cabbage to cooked dishes.
Chew Thoroughly: Chewing helps break down cells and starts the enzyme reaction in your mouth.

Health Benefits of Sulforaphane

Research highlights many potential health benefits of sulforaphane, including activating the body's antioxidant and detoxification systems.

Cellular Protection: It activates the Nrf2 protein, which protects cells and reduces inflammation.
Anti-Inflammatory: Sulforaphane can help reduce chronic inflammation.
Detoxification: It supports the liver's detoxification enzymes.
Cardiovascular Health: It may improve blood vessel function and cholesterol levels.
Brain Health: Studies explore its potential neuroprotective effects.

Conclusion: Making the Most of Sulforaphane

Broccoli sprouts are the leading source of sulforaphane due to their high concentration of glucoraphanin. However, obtaining the active compound depends on proper preparation to utilize the myrosinase enzyme. Incorporating raw sprouts or using methods like adding mustard seed powder can significantly increase sulforaphane intake. Understanding these principles helps you maximize the health potential of these vegetables.

Authority Link

For more in-depth scientific research on the anticancer properties of sulforaphane, consult the National Institutes of Health (NIH): Anticancer properties of sulforaphane: current insights at the molecular level

Frequently Asked Questions

Yes, but with a strategy. The freezing process can deactivate the myrosinase enzyme. To activate sulforaphane, sprinkle a pinch of mustard seed powder on the cooked frozen broccoli after thawing or cooking.

If you don't chop and let the vegetables rest, the conversion of glucoraphanin to sulforaphane will be significantly reduced, especially with high-heat cooking methods like boiling.

Food sources like broccoli sprouts provide sulforaphane along with other synergistic nutrients. Some supplements offer a precise dose, but whole food versions, particularly those with both glucoraphanin and active myrosinase, may offer a more holistic benefit.

For significant benefits, a typical recommendation is to eat around ½ cup (30–40 grams) of fresh broccoli sprouts daily.

For most individuals, consuming sulforaphane from food is safe. While some animal studies show adverse effects from very high doses, side effects from food intake are rare. Consult a healthcare provider if you have specific health conditions, such as thyroid issues, before taking supplements.

Other good sources include cauliflower, Brussels sprouts, kale, and cabbage. While they have less potential sulforaphane than sprouts, they are still valuable cruciferous vegetables.

Yes, your gut microbiota can convert some glucoraphanin into sulforaphane, even when the myrosinase enzyme from cooking is absent. However, this process is less efficient than the enzyme conversion that occurs when you chew raw vegetables.