So here's what I've searched from the internet:
Cauliflower is a member of the 'white' family in terms of fruits and vegetables. Included in this group are other natural foods such as bananas, mushrooms, onions, and garlic. Cauliflower contains allicin, which can improve heart health and reduce the risk of strokes, and selenium, a chemical that works well with Vitamin C to strengthen the immune system. Cauliflower can also help to maintain a healthy cholesterol level.
Folate is also found in cauliflower, which is a B vitamin that is needed for cell growth and replication. For this reason, it is often recommended that women who are pregnant or may become pregnant eat significant amounts of cauliflower in order to help their unborn children develop properly.
Of course, cauliflower is an excellent source of fiber, which helps to improve colon health and can even help prevent cancer. And, most recently, it has been discovered that cauliflower, as well as other cruciferous vegetables, such as brussel sprouts and cabbage, contain indole-3-carbinol, a substance that can affect the metabolism of estrogen in the body, and prevent breast and other female cancers.