The goitrogenicity of kale and its relation to thiocyanate content

The goitrogenic activities of small young leaves of different types of kale were compared using the depression of thyroid uptake of radioactive iodine in the rat as the index of goitrogenic activity. Rape kale was slightly more goitrogenic than the other types tested, thousand head, marrow stem, Canson and Maris Kestrel, but there were no large and consistent differences in activity among the kales studied. Small, young leaves of all kale types had much greater activity than corresponding large, fully formed leaves. The goitrogenic activities of thousand head, marrow stem, Canson and Maris Kestrel kales were attributable largely, if not wholly, to thiocyanate while only a small proportion of the activity of rape kale was given by thiocyanate.