Food
Cruciferous (brassica) vegetables in excess
Dietary factor.
Scientific evidence
Low-moderate
Sources
Our own summaries · Cited studies
In practice
It depends on the case; there is no single guideline.
Precautions
Relevant mainly with iodine deficiency or thyroid problems.
Effect by goal · level of evidence
harms Low-moderate study (A)
Cruciferous vegetables (cabbages, Brussels sprouts, some kale) release sulforaphane (anticancer) but also goitrin and thiocyanate, which can reduce iodine uptake by the thyroid. In large amounts and with iodine deficiency they could promote hypothyroidism; at normal intake the balance is favorable.
View the study (study) →In depth
Diet · Highest evidence: Low-moderate · 1 finding
⚠️ Relevant mainly with iodine deficiency or thyroid problems.
Findings
- Thyroid (hypothyroidism) — harms (Low-moderate, study). Cruciferous vegetables (cabbage, Brussels sprouts, some kale) release sulforaphane (anticancer) but also goitrin and thiocyanate, which can reduce iodine uptake by the thyroid. In large amounts and with iodine deficiency they could promote hypothyroidism; with normal consumption the balance is favorable. 26946249
Information, not medical advice. Prescription drugs require a doctor.
Information, not medical advice. Scientific evidence reflects the quality of the studies.