Glucoraphanin is not sulforaphane

A poorly-conceived and intentionally-misrepresented human 2022 broccoli product study:

“We investigated whether a sulforaphane (SFN) [actually, sulforaphane precursor glucoraphanin] intake intervention improved cognitive performance and mood states in healthy older adults in a 12-week, double-blinded, randomized controlled trial.

The SFN group showed improvement in processing speed and a decrease in negative mood compared to the placebo group. However, there were no significant results in other biomarkers of oxidant stress, inflammation, or neural plasticity.

These results indicate that nutrition interventions using SFN can have positive effects on cognitive functioning and mood in healthy older adults.” “Effects of sulforaphane intake on processing speed and negative moods in healthy older adults: Evidence from a randomized controlled trial”

Contrary to this study’s title, actual sulforaphane intake was not measured. The glucoraphanin product used in this study was the same item and daily dose as Eat broccoli sprouts for your workouts, which investigated effects with 19-to-23-year-old men. The treatment was taken all at once at an unspecified time of day rather than three times a day with young subjects.

These researchers knew from the 2012 study cited for dose that:

“Individual conversions of glucosinolates [like glucoraphanin] to isothiocyanates [like sulforaphane] varied enormously, from about 1% to more than 40% of dose. In contrast, administration of isothiocyanates (largely sulforaphane)-containing broccoli sprout extracts, resulted in uniformly high (70-90%) conversions to urinary dithiocarbamates.”

Young or old, a daily 30 mg glucoraphanin intake isn’t sufficient to fully activate human Nrf2 signaling pathways. A daily 17 mg sulforaphane intake could accomplish that.



6 thoughts on “Glucoraphanin is not sulforaphane

  1. Another excellent post. Thank you. I have a question please. I copied this from another of your posts: “I create isothiocyanates by microwaving 3-day-old broccoli / red cabbage / mustard sprouts at 1000 W to 60°C (140°F) shortly before eating them. Unlike this study, I don’t depend on metabolism after the stomach to produce isothiocyanates from glucosinolates”.
    I guess I have 2 questions:
    1: How can I microwave my sprouts to 60°C? Is there a formula based on the power of my MW?
    2: Could I just add 60°C water to my sprouts?

    I am eating a large bowl of broccoli and Daikon radish sprouts ever morning. Well over 60 grams. I would like to make sure I am getting some SFN into my system.

    Thanks, Dave

    • I guess my second question was answered in your other post on blanching broccoli sprouts. Sorry about that. So blanching is probably creating SFN right there in the bowl. Right?

      • Forgot to mention that regarding sulforaphane, the thermosonication study also found:
        “Maximum SF content among studied conditions was achieved using thermosonication treatment at 60 °C for 7 min, which represented a 192.6% increase compared to untreated broccoli florets. That was 15.8% higher than thermal treatment, indicating the potential of thermosonication for enhancing sulforaphane yield over and above effects of heat.”

        • And thank for the note on thermosonication. 192% increase is impressive, but like I think you wrote once, I can just eat twice as much (to paraphrase).

    • Hi Dave! The Increase broccoli compound amounts with thermosonication study lent credence to the Microwave broccoli to increase sulforaphane levels study by finding:
      “Our results showed that a combination of ultrasound with heat treatment (at 50 and 60 °C for 5 and 7 min) improved release of GR from broccoli matrix over and above heat treatment alone. This could be due to mechanical disruption of plant cell wall and plant matrix, which enhances release of intracellular content.”
      My current practice with a 1000W microwave is to heat 3-day-old sprouts with 100 ml water on high power for 38 seconds. Use a $5 candy thermometer.

      • Thank you so much! Tomorrow I will try microwaving a cup and a half of sprouts, with added water to the cup and a half line, to 60 degrees on high. My measurements show a cup of sprouts weighs about 40 grams. My sprouts are 1/3 daikon radish, so I go the extra half cup to make sure I have 40 grams of broccoli.
        Then I guess I will let it set for 5 minutes and hopefully it will produce SFN right there in the cup.
        One thing I read about the radish is the MYR is more temperature tolerant. I am trying this instead of adding mustard seed.
        Okay, I will shut up. Thanks so much.

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