Brassica vegetables represent cruciferous vegetables and are characterised with a high content of various biologically active compounds, thioglycosides (glucosinolates) especially. Enzymatic hydrolysis of glucosinolates gives numerous products such as isothiocyanate, thiocyanate and indole derivatives. Raw vegetables have the biggest amount of theses compounds, and their content decreases during thermal processes.

Experimental and epidemiological research showed consumption of brussels sprout, broccoli, cabbage and cauliflower decreased the risk of gastrointestinal tract cancer. Defensive mechanism of glucosinolates enzymatic decay products is related to induction of detoxication enzymes in gastrointestinal tract tissues, glutathione transferase mainly, which removes active forms of carcinogenic compounds. On the other hand, isothiocyanates and thiocyanates present goitrogenic activity. Antinutritional influence of those compounds includes hindering iodine absorption in thyroid gland, which leads to disorders in thyroid hormones synthesis.

Consumption of many vegetables of Brassica family is desirable because they are a source of many valuable nutritional elements, which have also anticarcinogenic effects. However, more iodine should be simultaneously provided. The presence of Brassica vegetables in everyday diet is an important method of cancer prophylaxis