Do Raw Broccoli and Cruciferous Vegetables Damage Thyroid Function?
Angelika's Question: I read that raw broccoli contains goitrogens that can inhibit thyroid function. And we should put it for 2 minutes in boiling water, so the sometimes bitter taste will also go away.
Andrew's Answer: You'll occasionally hear that some cruciferous vegetables, such as broccoli and cabbage, are goitrogenic.
This means that in laboratory conditions they've been shown to have a mild suppressant effect on thyroid function, which could theoretically lead to a low thyroid condition. No major correlation between high cruciferous vegetable consumption and thyroid issues have been borne out in population studies.
It's also worth pointing out that vegetable consumption has been correlated strongly with decreased risk of many diseases, and that it seems the far riskier move would be in forgoing vegetables.
As for boiling vegetables to decrease the risk, cooking a food never makes foods better, but only damages them. It's been argued that compounds that affect thyroid function are suppressed by cooking, but so too is the quality of the food as a whole. Better not to eat it at all if cooking is your only option.
I don't eat many cruciferous vegetables because they are harder for the body to digest than leafy greens and contain mildly-irritating oxalic acid.
However, I do have them occasionally and do not feel any concern over their inclusion.