# Sulforaphane from broccoli: what research shows about the Nrf2 pathway

> Sulforaphane only forms when broccoli is chopped - and it works differently from classic antioxidants. What the evidence supports, what it does not, and why processing is decisive.

Broccoli has a reputation as a healthy vegetable - but research is not primarily interested in its vitamins. The focus is on a sulphur compound that only forms once the plant cell is destroyed. Sulforaphane is one of the most intensively studied molecules in nutritional science.

## Glucoraphanin, myrosinase and what happens when you chop

Fresh broccoli contains no sulforaphane. It contains its precursor **glucoraphanin**, a glucosinolate, and separately the enzyme **myrosinase**. Only when cell walls rupture - through cutting, chewing or milling - do the two meet and glucoraphanin is converted into sulforaphane.

How broccoli is processed therefore matters more for sulforaphane yield than how much of it you eat. Vermeulen and colleagues (2008) compared cooked with raw broccoli in humans. The result: around three times more isothiocyanates were absorbed from raw broccoli. The reason is simple - myrosinase is heat-sensitive and destroyed by cooking.

## The Nrf2 pathway - why researchers pay attention

Sulforaphane does not act like a classic antioxidant that scavenges free radicals directly. Instead it flips a switch inside the cell: the **Nrf2 pathway**. Nrf2 is a transcription factor that, in the nucleus, triggers the reading of genes for so-called phase II enzymes - among them glutathione S-transferases and NAD(P)H quinone oxidoreductase.

Fahey, Zhang and Talalay first described this mechanism systematically in 1997. Dinkova-Kostova and Talalay call it an **indirect** antioxidant effect: the cell expands its own defences rather than consuming a substance supplied from outside. Said plainly and fairly: there are **no EFSA-approved health claims** for glucoraphanin or sulforaphane. The mechanistic evidence is strong, the human evidence still open. Anyone promising you more is selling you something.

## Fibre - the underrated part

With 24 g of fibre per 100 g, broccoli powder is a relevant fibre source. Fibre reaches the large intestine undigested and serves the microbiota as substrate, producing short-chain fatty acids such as butyrate. Slavin (2013) summarises the evidence on fibre and prebiotic effects.

Added to that are micronutrients with established function: **vitamin C** contributes to the normal function of the immune system and to the protection of cells from oxidative stress. **Vitamin K** contributes to normal blood clotting.

## How WOO® Brokkolipulver puts this into practice

[WOO® Brokkolipulver](/en/shop/woo-broccoli-powder-bag) is made of 100% Swiss organic broccoli and is gently freeze-dried - not heat-dried. In freeze-drying, frozen water sublimates directly under vacuum; the temperature stays low, which is decisive for heat-labile components and for retaining up to 98% of the natural nutrients.

One scoop (6 g) in 200 ml of water or into a smoothie, daily. 180 g covers 30 servings. Precisely for that reason WOO® Brokkolipulver belongs in the food category, not in the high-dose supplement category.

## Frequently asked questions

**Is powder equivalent to fresh broccoli?**
Not identical, but complementary. Freeze-dried powder largely retains fibre, vitamins and phytonutrients, yet it is no substitute for vegetables on the plate.

**When is the best time to take it?**
No time of day is evidence-based. What works is tying it firmly to an existing habit - breakfast or lunch. Consistency beats timing.

**Why not stir it into hot drinks?**
Because heat attacks enzymes and vitamin C. Cold water, yoghurt or a smoothie are the better choice.

## Sources

Fahey JW, Zhang Y & Talalay P (1997), PNAS - Broccoli sprouts: an exceptionally rich source of inducers of enzymes that protect against chemical carcinogens.
Vermeulen M et al. (2008), Journal of Agricultural and Food Chemistry - Bioavailability and kinetics of sulforaphane in humans after consumption of cooked versus raw broccoli.
Dinkova-Kostova AT & Talalay P (2008), Molecular Nutrition & Food Research - Direct and indirect antioxidant properties of inducers of cytoprotective proteins.
Slavin JL (2013), Nutrients - Fiber and prebiotics: mechanisms and health benefits.

*WOO® Brokkolipulver - in the NEMAPO shop.*