Four studies failed to demonstrate an inverse association with colorectal cancer, while a fifth found that people who consumed the equivalent of 2.5 cups of
crucifers per week had a decreased risk of colon cancer but an increased risk of rectal cancer compared to those who consumed the equivalent of one - half cup per week.2 A pooled analysis of eight studies on the relationship between fruit and vegetable consumption and breast cancer showed no relationship with
crucifers.25 None of four studies showed an inverse association with prostate cancer, but one of them found a 28 percent
reduced risk for the consumption of five servings of
crucifers per week compared to one serving per week when they limited the analysis to men who were diagnosed with the prostate specific antigen (PSA) test, which is considered a more sensitive diagnostic measurement.
Fermentation does not
reduce goitrogens in these veggies, but since fermented
crucifers such as sauerkraut are typically eaten as a condiment and, hence, in small amounts, consumption is fine if the diet is rich in iodine.