Virtanen’s work was strongly focused on agriculture and agricultural chemistry. Because one major purpose of agriculture is making food and because the properties of food largely impact our bodily functions, certain aspects of his work also reach into the sphere of human biochemistry. The present talk is a good example of this.
Virtanen discusses food goitrogens, substances that can disturb the function of the thyroid and cause thyroid enlargement (goiter). A principal, well-established cause of this disease is a lack of iodine. However, a large excess of iodine may also cause goiter and iodine may hence be considered a goitrogen itself. Other goitrogens can interfere with the iodine uptake of the thyroid or affect its enzymatic machinery.
Virtanen reviews the scientific knowledge with respect to goitrogens in food, mentioning several foodstuffs that have been associated to goiter development in laboratory animals. These include peanuts and plants of the Brassica genus, such as broccoli or cabbage. On this basis, he describes his own experiments, in which the transfer of goitrogens from cattle feed to milk is investigated. While some carryover was detected, Virtanen’s experiments ultimately suggested that only insignificant quantities of the goitrogens investigated are transferred to milk. He hence concludes that milk is essentially safe for the thyroid.
Today, more goitrogenic compounds are known than in 1960. They are not all covered by Virtanen’s experiments. It has furthermore been established that goitrogen precursors, which are inactive themselves, can be metabolically activated after ingestion. It is hence not sufficient to measure active goitrogens in a given foodstuff in order to assess its goitrogenic potential. In fact, there have been occasional reports on goiter endemics associated to milk since Virtanen’s talk .
Still, the issue is complex and other sources of goitrogens, such as bacterially contaminated drinking water, have also been identified. Furthermore, region-specific environmental conditions also play a strong role, making linking of endemic goiter to specific goitrogens a difficult task.
 E. Gaitan, Annual Review of Nutrition, 1990, 10, pages 21-39.