Broccoli sprouts

Also called: sulforaphane, cruciferous vegetables.

Last reviewed 2026-09-16. How this works.

Treating cancer Grade D

No human evidence of benefit, or none that survived testing.

Fourteen trials have tested this in people, and not one of them checked whether a cancer changed.

Fourteen completed trials in people, and every one of them measured a marker.

The claim

The claim is that sulforaphane, concentrated in broccoli sprouts, acts against cancer.

What it does

Sulforaphane activates a cellular defence pathway, and that pathway is real and well described. The human studies were designed to show it switching on, and several of them did.1

The evidence

This is not a compound nobody has studied in people. Fourteen completed trials are registered in cancer, across prostate, breast, lung, head and neck and precancerous skin lesions.1

Every one of them measured a marker. Nrf2 gene transcripts, Ki-67, histone deacetylase activity, metabolites in urine and blood, a fall in a blood protein. Not one measured whether a cancer came back, grew, or shortened anyone's life.1

That is the finding, and it is a more specific one than "no evidence". The field has been active for twenty years and has not yet taken the step from showing the pathway moves to showing a person is better off. This entry is the register's clearest example of the difference between the two.1

What is absent

No completed trial of broccoli sprouts in cancer has measured survival, recurrence or tumour response. Every registered completed study measured a marker instead.

Scope: any tumour type.

Established by registry search, ClinicalTrials.gov, query intervention "broccoli sprout", condition "cancer", status completed, checked 2026-09-16. Result: fourteen completed studies, every primary outcome a biomarker.1

What to ask

If a study only measured a marker in the blood, what would it take to know whether it helps anyone?

The dish-to-person gap

Broccoli sprout extract is eaten as food rather than taken as a measured compound, and the register holds no human pharmacokinetic measurement for it.

When to call your team — no warning signs are recorded

If you have changed how you eat because of something you have read, or are thinking about it, the people treating you can only weigh that if they know about it. That is true when nothing has been written down here, and it is most true then.

The register records no warning signs for this entry. That is not a statement that nothing can go wrong.

Interactions

The register holds no measured interaction between this food and a cancer treatment class. An empty list means nobody has measured it, not that nothing would happen. Concentrated extracts are a different question from the food.

Nobody having looked is not the same as nothing being there. That is what this line says and all it says.

The whole interaction list, and how to turn it into a pharmacy review request.

Find a trial instead

There is a great deal to find here. What there is not is a trial measuring what happened to anyone's cancer.

Search ClinicalTrials.gov for recruiting studies of broccoli sprout OR sulforaphane

A trial is the same decision with monitoring, a known preparation and a doctor who knows what else you are taking.

References

  1. A search of the ClinicalTrials.gov registry for completed studies of this intervention in cancer, run on 16 September 2026. 14 completed studies returned.

    https://clinicaltrials.gov/api/v2/studies?query.intr=broc…

    How this was reached: search run during build, via a search run during the content build; not a source the manuscript carries.