Sulforaphane: The little compound that completely changed the way I look at Broccoli

If you'd told me a couple of years ago that one day I'd have strong opinions about broccoli sprouts, I'd probably have laughed at you.

Yet here we are.

Of all the things I've discovered while disappearing down countless health and wellness rabbit holes, sulforaphane is one that has really stuck with me.

In fact, it's one of the supplements I personally intend to keep in my own routine long term.

But what actually is it — and why are researchers so interested in it?

First things first: what is sulforaphane?

Sulforaphane is a naturally occurring plant compound found in cruciferous vegetables such as broccoli, cauliflower, Brussels sprouts and kale.

But here's the interesting bit.

The plant doesn't simply sit there full of ready-made sulforaphane.

Instead, broccoli contains a precursor called glucoraphanin and an enzyme called myrosinase.

When the plant tissue is damaged — think chopping, crushing or chewing — glucoraphanin and myrosinase meet, and that reaction can produce sulforaphane.

It's essentially a tiny bit of plant chemistry happening on your chopping board.

And suddenly broccoli became much more interesting to me.

Then I discovered broccoli sprouts

This was another wait... WHAT? moment.

Young broccoli sprouts can contain considerably more glucoraphanin than mature broccoli. Research into three-day-old broccoli sprouts found concentrations around 10–100 times greater than the corresponding mature plants, although the amount varies considerably between varieties and growing conditions.

That is one of the reasons broccoli sprouts have become such an important source in sulforaphane research.

Tiny little sprouts. Rather impressive chemistry.

Why is everyone so interested in sulforaphane?

This is where my rabbit hole became considerably deeper.

Sulforaphane has been extensively studied for its effects on cellular pathways involved in the body's own protective responses.

One of the best-known is Nrf2.

Nrf2 is a signalling pathway involved in regulating genes associated with cellular defence and responses to oxidative and chemical stress.

Researchers are also investigating sulforaphane in areas including inflammation, metabolism, cardiovascular and neurological health, and cancer biology.

The cancer research was obviously particularly interesting to me.

Laboratory and animal studies have investigated effects involving cell-cycle regulation, apoptosis (the programmed death of damaged cells), inflammatory signalling, epigenetic mechanisms and other pathways involved in cancer development.

But there is an important distinction here.

Interesting cancer research does not mean sulforaphane has been proven to treat cancer in humans.

Human clinical research is much more limited and variable than the laboratory evidence, and researchers are still working out questions around dose, formulation, bioavailability and whether the biological effects seen in the laboratory translate into meaningful clinical outcomes.

That's something I think is incredibly important when we're talking about natural compounds.

I can be fascinated by the research — and choose something for myself — without turning promising science into a promise.

The part I didn't know: myrosinase matters

Here's something worth knowing if you've ever stood in front of a supplement shelf comparing broccoli products.

Glucoraphanin isn't the same thing as sulforaphane.

It needs to be converted.

And myrosinase helps make that conversion happen.

Human studies have demonstrated substantially greater sulforaphane bioavailability when active myrosinase is available. A 2026 randomised crossover study, for example, found that adding a myrosinase-containing mustard seed powder to glucoraphanin-rich broccoli seed extract approximately doubled average sulforaphane bioavailability compared with the broccoli seed extract alone.

Our gut bacteria can perform some conversion too, but this varies between people.

So when I'm looking at a sulforaphane or broccoli sprout supplement now, I don't just see the word broccoli on the front and assume they're all equivalent.

I want to know:

What is actually in it?

Does it provide sulforaphane itself?

Does it provide glucoraphanin?

Is there active myrosinase to help convert that glucoraphanin?

And what amount is actually being supplied?

Those details matter.

Food still counts

None of this means we need to turn broccoli into a capsule before it becomes worthwhile.

Quite the opposite.

Broccoli sprouts and other cruciferous vegetables are foods, and there are some wonderfully simple ways to preserve or improve the chemistry we're interested in.

Myrosinase is sensitive to heat, so prolonged cooking can reduce its activity. Research has also shown that adding an active source of myrosinase — mustard seed is one example — can improve sulforaphane formation from cooked broccoli.

Who knew a sprinkle of mustard powder could involve this much science?

Why sulforaphane earned a permanent place in my cabinet

My interest in sulforaphane began because of my own health journey, and naturally the cancer research caught my attention.

But the more I learned, the more interested I became in the broader biology behind it.

I don't take it because I believe one capsule is some magical answer.

I don't think health works like that.

For me, it's simply one of the compounds I've researched, found genuinely fascinating and decided deserves a place in myroutine.

Your decision may be completely different.

And that's really the point of The CYD Journal.

I'm not here to tell you what you should take.

I'm here to share the things I discover, explain why I've become interested in them, and hopefully give you enough information to start asking your own questions.

Because sometimes a rabbit hole starts with something as ordinary as broccoli.

And apparently sometimes you come out the other end with a favourite phytochemical. 😆

Read. Question. Learn. Choose for yourself.

— Anita
Choose Yourself Daily

This article shares general information and my personal experience. It isn't medical advice, and supplements aren't a substitute for individual medical care. If you have a medical condition, take medication, are pregnant or breastfeeding, or are considering a new supplement, discuss it with an appropriately qualified healthcare professional.