Kale is recommended for breast cancer

Kale has the highest levels of vitamins of all cruciferous vegetables (a vegetable group that also includes broccoli, cabbage, cauliflower, collard greens and brussels sprouts). Kale contains significant levels of vitamin C, vitamin A, vitamin K, calcium, iron and various other minerals. Kale is also a good dietary source of the lignan enterolactone. Kale has been shown to have antioxidant, antigenotoxic, anti-inflammatory and antimicrobial properties, and to be cardioprotective. Kale contains beta-carotene, lutein and other carotenoids, quercetin, ferulic acid, caffeic acid, selenium, kaempferol, sulforaphane, indole-3-carbinol (I3C), 3,3'-diindolylmethane (DIM) and several other isothiocyanates, sinigrin and other glucosinolate hydrolysis products, most of which have been reported to have anti-cancer properties. Kale and cruciferous vegetables more generally have been shown to inhibit the growth of human pancreatic cancer cells and to reduce the risk of occurrence of lung, gallbladder, bladder, prostate, ovarian and colorectal cancer.

Breast cancer-related effects of eating kale

Components of kale have been found to down-regulate hormone receptor expression, promote apoptosis, suppress cell cycle progression and inhibit angiogenesis of human breast cancer cells. Consumption of brassica vegetables 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 population studies. A Korean study found an association between kale consumption and lower incidence of breast cancer. Kale components quercetin, I3C and sulforaphane have all been shown increase the anti-cancer effects of the chemotherapy drug Taxol (paclitaxel).

Additional comments

Kale is healthiest when prepared by steaming and not by stir-frying. Non-organic kale must be washed very thoroughly to remove pesticide residue. Kale can reduce the bioavailability of iodine in the diet.

We recommend consuming kale and other cruciferous vegetables as food and against consuming components of them as pills (e.g. DIM pills). 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 kale 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.

Cruciferous vegetables contain thioglucoside compounds that can interfere with the formation of thyroid hormone.

Tags: DIM, I3C, Indole-3-carbinol, Korean, Taxol, angiogenesis, aromataseActivity, betaCarotene, calcium, cardiovascular, carotenoids, chemotherapy, enterolactone, estrone, inflammation, iodine, iron, isothiocyanates, kaempferol, kale, lignan, lutein, ovarianCancer, paclitaxel, proliferation, quercetin, selenium, sulforaphane, thyroid, vitaminA, vitaminC

Selected breast cancer studies
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Cruciferous vegetables and cancer risk in a network of case-control studies The Safety of Cruciferous Plants in Humans: A Systematic Review Carotenoid intakes and risk of breast cancer defined by estrogen receptor and progesterone receptor status: a pooled analysis of 18 prospective cohort studies Fruit and vegetables consumption and breast cancer risk: the EPIC Italy study Kaempferol protects against doxorubicin-induced cardiotoxicity in vivo and in vitro Natural isothiocyanates: Genotoxic potential versus chemoprevention Serum enterolactone levels and mortality outcome in women with early breast cancer: a retrospective cohort study Sulforaphane inhibits the growth of KPL-1 human breast cancer cells in vitro and suppresses the growth and metastasis of orthotopically transplanted KPL-1 cells in female athymic mice Serum enterolactone and postmenopausal breast cancer risk by estrogen, progesterone and HER2 receptor status Fruit and Vegetable Intake in Relation to Risk of Breast Cancer in the Black Womens Health Study Flavonoids, Proanthocyanidins, and Cancer Risk: A Network of Case-Control Studies From Italy Glucoraphanin hydrolysis by microbiota in the rat cecum results in sulforaphane absorption p53-Independent Apoptosis by Benzyl Isothiocyanate in Human Breast Cancer Cells Is Mediated by Suppression of XIAP Expression Circulating Carotenoids, Mammographic Density, and Subsequent Risk of Breast Cancer HDAC inhibitors trigger the autophagic switch from prosurvival to prodeath in tamoxifen-treated breast cancer cells Leafy Vegetable Mix Supplementation Improves Lipid Profiles and Antioxidant Status in C57BL/6J Mice Fed a High Fat and High Cholesterol Diet Regulation of estrogen receptor α expression in human breast cancer cells by sulforaphane Indole-3-carbinol inhibits MDA-MB-231 breast cancer cell motility and induces stress fibers and focal adhesion formation by activation of Rho kinase activity Steam cooking significantly improves in vitro bile acid binding of collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage Cruciferous vegetables, the GSTP1 Ile105Val genetic polymorphism, and breast cancer risk Preclinical and clinical evaluation of sulforaphane for chemoprevention in the breast Comparisons of food intake between breast cancer patients and controls in Korean women Effects of the isothiocyanates sulforaphane and erucin on breast cancer and normal human mammary epithelial cells 3,3'-Diindolylmethane inhibits angiogenesis and the growth of transplantable human breast carcinoma in athymic mice Breast cancer risk in premenopausal women is inversely associated with consumption of broccoli, a source of isothiocyanates, but is not modified by GST genotype Inhibitory effect of whole strawberries, garlic juice or kale juice on endogenous formation of N-nitrosodimethylamine in humans Analysis of 200 food items for benzo[a]pyrene and estimation of its intake in an epidemiologic study Estrogenic Effects of Extracts from Cabbage, Fermented Cabbage, and Acidified Brussels Sprouts on Growth and Gene Expression of Estrogen-Dependent Human Breast Cancer (MCF-7) Cells Brassica vegetable consumption shifts estrogen metabolism in healthy postmenopausal women