Cruciferous vegetables (or brassicas) are thought to play an important role in cancer prevention. These vegetables contain phytochemicals known as isothiocyanates. These phytochemicals change the way estrogen is metabolized or broken down in the body. This, in turn, decreases the risk of hormone- or estrogen-related cancers like breast and uterine cancer. Isothiocyanates are activated by chopping or chewing the cruciferous vegetables containing them.
In addition to isothiocyanates, cruciferous vegetables are important sources of protein, fiber, vitamins, and minerals. Most people don’t realize that plant foods are sources of protein, but a cup of cruciferous vegetables provides about 3 grams. For comparison, that’s the same amount of protein found in half an ounce of chicken breast. Additionally, the high fiber content of cruciferous vegetables can aid digestion and improve the health of gut bacteria. Cruciferous vegetables are also good sources of vitamin A, vitamin C, vitamin K, and manganese.
Eating a serving of these vegetables daily (particularly broccoli, kale, and Brussels sprouts) can help lower the risk of disease. To retain the full array of nutrients, it is best to eat cruciferous vegetables either raw, steamed, or lightly sautéed.
Bok choy (pak choi)
Broccoli rabe (rapini) Brussels sprouts
Cabbage (all varieties)
Dark leafy greens (all) Horseradish
Source: The Institute for Functional Medicine