Proper cabbage preparation and cooking methods are essential for receiving its cancer-preventive effects.Cabbage's anti-carcinogenic glucosinolates are formed by the activity of myrosinase enzymes, which are released when cabbage is sliced or chopped. Cooking denatures the myrosinase enzyme, thus stopping the production of glucosinolates.

Research has found that the association between frequently eating cabbage and a significantly reduced risk of breast cancer is only seen with raw and short-cooked cabbage foods (steamed cabbage and sauerkraut), not long-cooked cabbage recipes (hunter's stew, cabbage rolls, pierogi). To promote the production of the most glucosinolates, slice or chop your cabbage and let sit for 5-10 minutes before cooking, and cook lightly, steaming or sautéing for 5 minutes or less.