Eating broccoli and kale won’t hurt your thyroid if you’re getting enough iodine, like from iodized salt or seafood.
Scientific Claim
Consumption of cruciferous vegetables like kale and broccoli is not associated with thyroid dysfunction in individuals with adequate iodine intake, despite the presence of goitrogenic compounds.
Original Statement
“In contrast, progoitrin-rich rutabaga sprouts had no impact on thyroid function in healthy rats. Human studies show no correlations between cruciferous vegetable intake and thyroid function in iodine-replete individuals.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design cannot support claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The claim uses 'is not associated' to reflect observational and epidemiological data, avoiding causal language. This is appropriate given the study design.
Evidence from Studies
Supporting (1)
This study says that even though veggies like broccoli and kale have chemicals that might seem bad for the thyroid, they’re perfectly safe if you get enough iodine — which most people do — so there’s no need to avoid them.