Cruciferous vegetables and cancer:
An extensive review of epidemiological studies published prior to 1996 reported that the majority (67%) of 87 case-control studies found an inverse association between some type of brassica vegetable intake (including cabbage, kale, broccoli, Brussels sprouts, and cauliflower) and cancer risk at various sites. For cabbage, broccoli, cauliflower, and Brussels sprouts, these percentages were 70, 56, 67, and 29%, respectively. The results of 7 cohort studies also showed an inverse relationship between brassica consumption and risk of cancer. The higher the consumption of brassica vegetables the lower the risk of cancer. The inverse association appeared to be most consistent for cancers of the lung and digestive tract and least consistent for prostatic, endometrial, and ovarian cancer. In summary, a high consumption of brassica vegetables is associated with a decreased risk of cancer. (36)