Systematic reviewindependent cross-checkabstract checked★ key study I-VEG-127 standard review

Cabbage-family vegetables are not bad for the thyroid

Do Brassica Vegetables Affect Thyroid Function?-A Comprehensive Systematic Review.

Overview

Galanty A et al.. Int J Mol Sci 2024 · PMID 38612798 · DOI 10.3390/ijms25073988

A review of 123 studies concluded that daily brassica vegetables, especially with enough iodine, do not harm thyroid function.

Does the study support the specific claim? No · Methodological quality: low

Study explained simply

What did the researchers want to find out?: Assess thyroid effects of brassicas.
How was the study done?: Systematic review.
How many people, animals or samples were studied?: 123 articles.
What was actually found?: No adverse effect at dietary intakes with adequate iodine.
How large was the observed effect?: Not quantified.
What do the results mean in everyday life?: Normal amounts of cabbage, broccoli or bok choy are fine for the thyroid.
What are the study's limitations?: Mixed study types.
What does it say about Elawady's specific claim?: Contradicts the claim.
Do the results apply to Germany and Europe?: Applicable.
What can explicitly not be concluded from this study?: Cannot exclude effects at extreme raw intakes with iodine deficiency.

Authors: Galanty A et al.
Journal: Int J Mol Sci
Year: 2024
Identifier: PMID 38612798 DOI 10.3390/ijms25073988
Verification: verified – PubMed efetch 2026-10-26; Crossref 2026-10-26
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: COI statement: The authors declare no conflicts of interest. | Funding (PubMed grant list): This research was funded by the following grants from the Polish Ministry of Education and Science:

Do Brassica vegetables affect thyroid function?

Study design: Systematic review – Systematic review (PRISMA) of in vitro, animal and human studies
Population: In vitro, animal and human studies
Country: Multiple
Period: not stated in abstract
Sample size: 123 articles
Inclusion and exclusion criteria: not stated in abstract

Exposure / intervention: Brassica vegetables, extracts, glucosinolates, isothiocyanates
Comparator: Various
Endpoints: Thyroid mass/histology, TSH, T3, T4, iodine uptake, thyroid cancer cells
Statistical methods: Narrative synthesis

Results: The vast majority of results cast doubt on antithyroid effects of brassica plants in humans; including brassica vegetables in the daily diet, particularly with adequate iodine intake, poses no adverse effects on thyroid function.
Absolute risks: not reported
Authors' conclusion: Brassica vegetables in the daily diet, especially with adequate iodine, are not associated with adverse thyroid effects.

Orienting tool: AMSTAR 2
Type of assessment: simplified assessment (abstract only)
Full formal assessment: no
Overall risk of bias: some concerns
Rationale: No quantitative synthesis; quality appraisal not described in abstract.

No pooled estimate.

Directly addresses goitrogenic concern for normal consumption.

Chu 2010 case (A-VEG-07); Felker 2016 (some varieties have high goitrin).

Applicable.

Contradicts generalisation from a single extreme case.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	low
Risk of bias	some concerns
Precision of results	not applicable
Directness	direct
Reproducibility	unknown
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Human trials in iodine-deficient settings.