These vegetables are known to be high in important nutrients such as vitamin C and selenium, and they also contain hundreds of plant compounds that are known to fight cancer. One of these groups, isothiocyanates, has gained enormous attention over the last few years as an anti-cancer "medicine" provided by foods.
There have been 55 key epidemiological studies conducted on the relationship between cruciferous vegetable intake and cancer, according to the World Cancer Research Fund. Sixty-nine percent of those studies show a positive correlation between cruciferous vegetable intake and lower cancer risk. Interestingly, few of these studies tracked raw vegetable intake vs. cooked intake, and there is little doubt that the 31 percent of the studies showing no cancer risk decrease were likely tracking the intake of cooked vegetables. (Modern nutritional researchers remain ignorant about living foods vs. cooked foods, and they group them all together, oblivious to the fact that cooked foods lack the natural medicine of raw foods...)
Isothiocyanates inhibit both cancer and tumor development by directly blocking the carcinogenic action of free radicals. In other words, they prevent free radicals from attacking healthy cells and turning them cancerous. One specific variety, phenethyl-isothiocyanate, has even been shown to induce cell death in certain cancer lines, including those that are resistant to chemotherapy drugs. Many oncologists remain stubborn, however, insisting that cancer patients should never use food to treat cancer.