Broccoli and broccoli sprouts are a good source of vitamin C and vitamin K and have been shown to suppress inflammation. Broccoli contains numerous substances with suspected or demonstrated cancer fighting properties, including allyl isothiocyanate, beta-carotene, choline, indole-3-carbinol (I3C) and 3,3'-diindolylmethane (DIM), kaempferol, soluble fiber, and sulforaphane. Broccoli has been shown to inhibit urinary bladder carcinogenesis and reduce the risk of occurrence of multiple myeloma and lung, gallbladder, ovarian, cervical, stomach, prostate, small intestine and colorectal cancers.
Breast cancer-related effects of eating broccoli
Broccoli has been found to promote apoptosis, suppress cell cycle progression and inhibit angiogenesis of human breast cancer cells. Consumption of broccoli has been shown to reduce the estrogen metabolite 16alpha-hydroxyestrone, which is a breast cancer promoter, and to be marginally inversely associated with breast cancer risk in a population of premenopausal women. Broccoli components I3C and sulforaphane have all been shown increase the anti-cancer effects of the chemotherapy drug Taxol (paclitaxel). Broccoli sprouts are particularly rich in anticancer nutrients.
Broccoli sprouts generally are safer to eat compared to some other sprouts (for example, alfalfa sprouts, which have been linked to a number of food-borne disease outbreaks due to salmonella and E. coli). Stir frying preserves most of the presumed cancer-fighting chemicals in broccoli whereas after boiling only 14-28% of the individual glucosides are retained in the cooked tissue (most of the remainder being leached into the water). Similarly, if broccoli is microwaved, it should be done for the shortest period of time and with the least amount of water possible to minimize leaching of phenolic compounds and glucosinolates into water. Even the light blanching used in making frozen broccoli substantially reduces the bioavailability of sulforaphane.
We recommend consuming broccoli as food and against consuming broccoli pills that have been enhanced to boost the proportion of the presumed key anti-cancer chemicals in broccoli. There is some evidence that concentrated cruciferous vegetable extracts can act as estrogen agonists and promote breast cancer cell proliferation. Also, the anticancer properties of broccoli are likely to be the result of synergistic interaction of its various chemical components - isolated components have successfully inhibited proliferation in the laboratory, but their efficacy and safety in humans needs to be evaluated in large scale clinical trials.
Below are links to recent studies concerning this food. For a more complete list of studies, please click on broccoli.