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Broccoli & Cruciferous Vegetables

Broccoli and cruciferous vegetables as functional foods: observational meta-analyses on cancer and prostate cancer, and why they are not proof.

Content last updated . This page has not been medically reviewed.

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Overview

Cruciferous vegetables include broccoli, Brussels sprouts, cabbage, cauliflower and kale. They contain glucosinolates.

What the research shows

QuestionFindingEvidence type
Any cancerAn updated meta-analysis of observational studies found broccoli intake associated with lower cancer risk: case-control OR 0.64 (0.58 to 0.70); cohort RR 0.89 (0.82 to 0.96). The authors note people with cancer ate less broccoli and call for more cohort studies. [1]Observational
Prostate cancerHighest versus lowest intake of cruciferous vegetables: RR 0.87 (0.80 to 0.95); a significant linear trend with intake. [2]Observational

Case-control results are more favorable than cohort results, which is a warning sign for bias. Proper evidence from trials that eating cruciferous vegetables prevents cancer was not found.

Safety and individual considerations

  • Vitamin K: Brussels sprouts are listed among high-vitamin-K foods for people on warfarin; keep intake consistent and ask your anticoagulation clinic. [3]
  • Raw cruciferous vegetables can cause gas.
  • Thyroid conditions: we did not find a source we could read on food amounts and thyroid medicines, so we make no claim; ask a clinician.

Related

Leafy greens · Tomatoes

Frequently asked questions

Does broccoli prevent cancer?

Observational studies show associations, with the authors cautioning about bias. [1]

References

  1. Baladia E et al. Broccoli Consumption and Risk of Cancer: An Updated Systematic Review and Meta-Analysis of Observational Studies. Nutrients 2024. PMID 38892516.
  2. Long J et al. Cruciferous Vegetable Intake and Risk of Prostate Cancer: A Systematic Review and Meta-Analysis. Urol Int 2023. PMID 37343525.
  3. Cedars-Sinai. For Warfarin: Eating a Consistent Vitamin K Diet. Patient education page; ask your anticoagulation clinic for your own plan.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.