Adding mustard powder to cooked broccoli increased sulforaphane absorbed by people
What it found
Adding 1 g of powdered brown mustard to 200 g of cooked broccoli more than quadrupled the amount of sulforaphane found in urine over 24 hours.
This was measured in 12 healthy adults.
What they found
Studies in people
More sulforaphane with mustard
When the 12 adults ate cooked broccoli alone, they passed an average of 9.8 µmol of the sulforaphane marker per gram of creatinine in their urine over 24 hours. When they added 1 g of mustard powder, this rose to 44.7 µmol per gram of creatinine, an increase of over four times.
Variation between people
The extra sulforaphane from adding mustard varied a lot between individuals. The increase ranged from 1.7 times to 10 times more compared with eating cooked broccoli alone.
Animal and lab studies
Sulforaphane in lab tests
In lab tests, raw broccoli contained 2.05 µmol of sulforaphane per gram of dry weight, while cooked broccoli had 1.06 µmol. Adding 1 g of mustard powder to the cooked broccoli in the lab raised the level eightfold to 8.58 µmol per gram of dry weight.
Cooking destroys the enzyme
Lab tests showed that cooking broccoli at 100 °C for just 2 minutes destroyed 40% of its myrosinase enzyme activity. After 8 minutes of cooking, no measurable enzyme activity remained.
What the authors conclude
- They conclude that adding powdered brown mustard to cooked broccoli greatly increases the amount of sulforaphane the body can absorb.
- They note that the size of this benefit may vary depending on differences between individual plants and between individual people, including genetic differences in how enzymes process these compounds.
How it was done
Cooking broccoli destroys an enzyme called myrosinase, which is needed to turn a natural plant compound into sulforaphane. Scientists wanted to see if adding mustard powder, which contains active myrosinase, could restore sulforaphane formation in people eating cooked broccoli.
Twelve healthy adults aged 18 to 64 ate 200 g of cooked broccoli on two separate days, seven days apart. On one day they ate it plain and on the other they ate it mixed with 1 g of powdered brown mustard seed. All their urine was collected for 24 hours after each meal to measure a breakdown product of sulforaphane.
What it can’t tell you
- This trial only measured a chemical marker in urine, so it cannot show whether the extra sulforaphane leads to any specific health benefits or disease prevention.
- The study involved only 12 people, so scientists do not yet know if the exact size of the effect would be the same in a larger group.
Who paid
- Funding
- Funded by TETFund (Tertiary Education Trust Fund) Nigeria (from the PubMed record).
- Authors work at
- University of Reading, UK
The paper
- Title
- Supplementation of the Diet by Exogenous Myrosinase via Mustard Seeds to Increase the Bioavailability of Sulforaphane in Healthy Human Subjects after the Consumption of Cooked Broccoli
- Type
- Randomised controlled trial
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Okunade O, Niranjan K, Ghawi SK, Kuhnle G, Methven L (2018). Supplementation of the Diet by Exogenous Myrosinase via Mustard Seeds to Increase the Bioavailability of Sulforaphane in Healthy Human Subjects after the Consumption of Cooked Broccoli. Molecular nutrition & food research. doi:10.1002/mnfr.201700980Free full textPubMed 29806738DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error