Mustard powder with cooked broccoli raises sulforaphane
What it found
In 12 healthy adults, adding 1 g of powdered brown mustard to cooked broccoli increased the amount of a sulforaphane byproduct in their urine over 24 hours.
The increase was more than four times higher than with cooked broccoli alone.
What they found
Studies in people
Urinary sulforaphane byproduct
After eating cooked broccoli alone, participants excreted on average 9.8 micromoles of sulforaphane N-acetyl-L-cysteine per gram of creatinine in 24 hours. With added mustard powder, this rose to 44.7 micromoles per gram of creatinine.
Individual variation
The increase in sulforaphane byproduct from the mustard meal varied widely between people, from 1.7 times to 10 times higher than with broccoli alone.
Animal and lab studies
Sulforaphane in broccoli samples
In lab tests, raw broccoli contained 2.05 micromoles of sulforaphane per gram dry weight, cooked broccoli had 1.06, and cooked broccoli with 1 g mustard powder had 8.58, an 8-fold increase.
Cooking destroys myrosinase
Cooking broccoli for 2 minutes caused a 40% loss of myrosinase activity, 6 minutes caused 90% loss, and after 8 minutes no activity was measurable.
What the authors conclude
- They conclude that adding powdered brown mustard to cooked broccoli greatly enhances the formation of sulforaphane compared to cooked broccoli alone.
- They say this confirms that the presence of plant myrosinase is important for sulforaphane bioavailability.
- They note that this conclusion must be considered within the context of both plant and human variability.
How it was done
Cooking broccoli destroys the enzyme myrosinase, which is needed to turn glucoraphanin into sulforaphane, a compound reported to have anti-cancer activity. The authors wanted to see if adding an active myrosinase source, like powdered mustard seed, could boost sulforaphane formation in people.
Twelve healthy non-smoking adults, aged 18 to 64, ate 200 g of cooked broccoli with and without 1 g of powdered brown mustard in a randomised crossover study. They collected all urine for 24 hours after each meal, with a 7-day washout between visits.
What it can’t tell you
- The study cannot show whether the increase in sulforaphane happened before eating, during chewing, or during digestion.
- It cannot show whether this increase in a urine marker leads to any health benefit.
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 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error