Following a high-nutrient diet rich in G-BOMBS, as described in my book Super Immunity protects against many chronic diseases, breast cancer included. Green vegetables and mushrooms are the most powerful anti-breast cancer foods. Take note that a vegetarian diet does not show protection against breast cancer as much as a diet rich in green vegetables, beans, mushrooms, onions, berries, nuts and seeds. It is the phytochemical nutrient density and diversity of the diet that offers the most dramatic protection against cancer, not merely the avoidance of meat or fat.1-5
Vegetables and fruits have been consistently associated with both reduced risk of breast cancer and improved survival of breast cancer patients.3,4,6-8 Cruciferous vegetables contain powerful anti-cancer compounds that halt the growth of breast cancer cells and promote excretion of estrogen.2,9,10 Mushrooms block tumor growth and have anti-estrogenic activity – regular consumption of mushrooms – as little as one mushroom per day – has been shown to decrease breast cancer risk by up to 60-70%.1,5,11 Organosulfur compounds in onions and garlic also prevent the development of cancers by detoxifying carcinogens, halting cancer cell growth, and preventing tumors from obtaining a blood supply.12
Flax and chia seeds are the richest sources of lignans, phytochemicals with anti-estrogenic effects which also inhibit cell growth in breast tumors.13,14 In fact, in one notable study of women who were scheduled to have breast tumors removed, half ate a flax-containing muffin and the other half ate a control muffin daily, for 32-39 days until surgery. Their tumor tissue was analyzed, and even in this short timeframe, there was significant apoptosis (tumor cell death) and reduced cell proliferation of tumor cells in the flaxseed group.14
Consuming more protein and especially dairy products raises blood levels of insulin-like growth factor 1 (IGF-1), and elevated IGF-1 levels have been associated with increased in breast cancer risk in many studies.15 Higher fish consumption in women has also been linked to higher rates of breast cancer.16 Agricultural and industrial carcinogens, such as dioxins, accumulate in fatty tissues. Humans’ primary mode of exposure to these dangerous chemicals is from meat, poultry, fish, and dairy fat.17
Steaming vegetables, wokking or making vegetable soups should be the major extent of cooking. High temperature dry cooking produces potentially carcinogenic compounds – acrylamide (formed in starchy foods like French fries) and heterocyclic amines (formed in meats).18-20 For example, chicken cooked at high temperatures is known to contain a heterocyclic amine called PhiP, which is a breast carcinogen.21-23
A high-glycemic diet has been associated with greater risk of breast cancer and greater risk of recurrence in breast cancer survivors.24, 25 Insulin is a growth-promoting hormone, and chronic exposure to high-glycemic refined carbohydrates leads to chronic hyperinsulinemia, which could accelerate the growth of cancerous cells. This includes white flour, white rice, sugar, honey, maple syrup and other insulin-promoting processed foods.26
Make sure your multivitamin and other supplements do not contain folic acid. Also do not use nutritional yeast fortified with folic acid. Folic acid is found in most multivitamins and prenatal vitamins, and is associated with increased risk of breast cancer, whereas folate from natural food sources is associated with decreased risk.27-31 Folic acid is synthetic, not found in nature, whereas green vegetables are loaded with folate (the real thing).
Vitamin D helps to prevent cancer by opposing inflammation and proliferation of cancerous cells. In addition, vitamin D appears to have more specific breast cancer-preventive properties, based on studies showing that vitamin D has anti-estrogenic effects in breast cancer cells.32
Three-quarters of women who have breast cancer are vitamin D deficient, and maintaining sufficient blood vitamin D levels is associated with reduced risk of breast cancer diagnosis or recurrence.33-36 Some studies caution against vitamin D levels that are too high.37 Make sure you are taking the right amount by confirming with a 25(OH)D blood test. I advise aiming for the sweet spot of 30-45 ng/ml.
An analysis of 73 different studies concluded that women with high levels of physical activity reduced their risk of breast cancer by 25%.38,39 Maintaining a healthy weight is also extremely important, since 17% of breast cancer cases have been attributed to obesity alone.40
More than fifty studies have been conducted on the influence of alcohol on breast cancer risk. Even light drinking (one or fewer alcoholic drinks per day) is associated with increased risk; for example, data from the Nurses’ Health Study suggested that women consuming 3-6 alcoholic drinks weekly increased their breast cancer risk by 15% compared to non-drinkers.41,42 In breast cancer survivors, drinking 3-4 alcoholic beverages per week increased the risk of recurrence by 34%.43
Eating a Nutritarian diet helps keep your immune system strong to prevent infections. One reason this is important is the risk associated with taking antibiotics: breast cancer risk has been found to increase with number of days of antibiotic use.44
A Nutritarian diet also helps you avoid medications for blood pressure and cholesterol lowering that can increase cancer risk. Statin drugs are associated with a greater risk of breast cancer in older women.45 Likewise, calcium channel blockers and diuretics (used to lower blood pressure) have also been linked to greater risk.46,47
Shin A, Kim J, Lim SY, et al. Dietary mushroom intake and the risk of breast cancer based on hormone receptor status. Nutr Cancer 2010, 62:476-483.
Higdon J, Delage B, Williams D, Dashwood R. Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis. Pharmacol Res 2007, 55:224-236.
Gandini S, Merzenich H, Robertson C, Boyle P. Meta-analysis of studies on breast cancer risk and diet: the role of fruit and vegetable consumption and the intake of associated micronutrients. Eur J Cancer 2000, 36:636-646.
Zhang CX, Ho SC, Chen YM, et al. Greater vegetable and fruit intake is associated with a lower risk of breast cancer among Chinese women. Int J Cancer 2009, 125:181-188.
Zhang M, Huang J, Xie X, Holman CD. Dietary intakes of mushrooms and green tea combine to reduce the risk of breast cancer in Chinese women. Int J Cancer 2009, 124:1404-1408.
Boggs DA, Palmer JR, Wise LA, et al. Fruit and Vegetable Intake in Relation to Risk of Breast Cancer in the Black Women's Health Study. Am J Epidemiol 2010.
McEligot AJ, Largent J, Ziogas A, et al. Dietary fat, fiber, vegetable, and micronutrients are associated with overall survival in postmenopausal women diagnosed with breast cancer. Nutr Cancer 2006, 55:132-140.
Pierce JP, Stefanick ML, Flatt SW, et al. Greater survival after breast cancer in physically active women with high vegetable-fruit intake regardless of obesity. J Clin Oncol 2007, 25:2345-2351.
Watercress may 'turn off' breast cancer signal [http://www.soton.ac.uk/mediacentre/news/2010/sep/10_94.shtml]
Rose P, Huang Q, Ong CN, Whiteman M. Broccoli and watercress suppress matrix metalloproteinase-9 activity and invasiveness of human MDA-MB-231 breast cancer cells. Toxicol Appl Pharmacol 2005, 209:105-113.
Hong SA, Kim K, Nam SJ, et al. A case-control study on the dietary intake of mushrooms and breast cancer risk among Korean women. Int J Cancer 2008, 122:919-923.
Powolny A, Singh S. Multitargeted prevention and therapy of cancer by diallyl trisulfide and related Allium vegetable-derived organosulfur compounds. Cancer Lett 2008, 269:305-314.
Sturgeon SR, Heersink JL, Volpe SL, et al. Effect of dietary flaxseed on serum levels of estrogens and androgens in postmenopausal women. Nutr Cancer 2008, 60:612-618.
Thompson LU, Chen JM, Li T, et al. Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer. Clin Cancer Res 2005, 11:3828-3835.
Key TJ, Appleby PN, Reeves GK, Roddam AW. Insulin-like growth factor 1 (IGF1), IGF binding protein 3 (IGFBP3), and breast cancer risk: pooled individual data analysis of 17 prospective studies. The lancet oncology 2010, 11:530-542.
Stripp C, Overvad K, Christensen J, et al. Fish intake is positively associated with breast cancer incidence rate. J Nutr 2003, 133:3664-3669.
U.S. Environmental Protection Agency: Dioxins and Furans [http://www.epa.gov/pbt/pubs/dioxins.htm]
Zheng W, Lee S-A. Well-Done Meat Intake, Heterocyclic Amine Exposure, and Cancer Risk. Nutr Cancer 2009, 61:437-446.
Hogervorst JG, Baars BJ, Schouten LJ, et al. The carcinogenicity of dietary acrylamide intake: a comparative discussion of epidemiological and experimental animal research. Crit Rev Toxicol 2010, 40:485-512.
Pedersen GS, Hogervorst JG, Schouten LJ, et al. Dietary acrylamide intake and estrogen and progesterone receptor-defined postmenopausal breast cancer risk. Breast Cancer Res Treat 2010, 122:199-210.
Fu Z, Deming SL, Fair AM, et al. Well-done meat intake and meat-derived mutagen exposures in relation to breast cancer risk: the Nashville Breast Health Study. Breast Cancer Res Treat 2011.
Lauber SN, Gooderham NJ. The cooked meat-derived mammary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine promotes invasive behaviour of breast cancer cells. Toxicology 2011, 279:139-145.
Thomson B. Heterocyclic amine levels in cooked meat and the implication for New Zealanders. Eur J Cancer Prev 1999, 8:201-206.
Mullie P, Koechlin A, Boniol M, et al. Relation between Breast Cancer and High Glycemic Index or Glycemic Load: A Meta-analysis of Prospective Cohort Studies. Crit Rev Food Sci Nutr 2016, 56:152-159.
Sieri S, Pala V, Brighenti F, et al. High glycemic diet and breast cancer occurrence in the Italian EPIC cohort. Nutrition, metabolism, and cardiovascular diseases : NMCD 2012.
Vigneri P, Frasca F, Sciacca L, et al. Diabetes and cancer. Endocr Relat Cancer 2009, 16:1103-1123.
Charles D, Ness AR, Campbell D, et al. Taking folate in pregnancy and risk of maternal breast cancer. BMJ 2004, 329:1375-1376.
Kim YI. Does a high folate intake increase the risk of breast cancer? Nutr Rev 2006, 64:468-475.
Sellers TA, Grabrick DM, Vierkant RA, et al. Does folate intake decrease risk of postmenopausal breast cancer among women with a family history? Cancer Causes Control 2004, 15:113-120.
Sellers TA, Kushi LH, Cerhan JR, et al. Dietary folate intake, alcohol, and risk of breast cancer in a prospective study of postmenopausal women. Epidemiology 2001, 12:420-428.
Stolzenberg-Solomon RZ, Chang SC, Leitzmann MF, et al. Folate intake, alcohol use, and postmenopausal breast cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Am J Clin Nutr 2006, 83:895-904.
Krishnan AV, Swami S, Feldman D. The potential therapeutic benefits of vitamin D in the treatment of estrogen receptor positive breast cancer. Steroids 2012, 77:1107-1112.
Rose AA, Elser C, Ennis M, Goodwin PJ. Blood levels of vitamin D and early stage breast cancer prognosis: a systematic review and meta-analysis. Breast Cancer Res Treat 2013, 141:331-339.
Kim Y, Je Y. Vitamin D intake, blood 25(OH)D levels, and breast cancer risk or mortality: a meta-analysis. Br J Cancer 2014, 110:2772-2784.
Chen P, Hu P, Xie D, et al. Meta-analysis of vitamin D, calcium and the prevention of breast cancer. Breast Cancer Res Treat 2010, 121:469-477.
Bauer SR, Hankinson SE, Bertone-Johnson ER, Ding EL. Plasma vitamin D levels, menopause, and risk of breast cancer: dose-response meta-analysis of prospective studies. Medicine (Baltimore) 2013, 92:123-131.
Zittermann A, Iodice S, Pilz S, et al. Vitamin D deficiency and mortality risk in the general population: a meta-analysis of prospective cohort studies. Am J Clin Nutr 2012, 95:91-100.
Friedenreich CM. The role of physical activity in breast cancer etiology. Semin Oncol 2010, 37:297-302.
American Institute for Cancer Research: The Exercise Factor [http://www.aicr.org/site/News2?page=NewsArticle&id=7651&news_iv_ctrl=0&abbr=pub_]
American Institute for Cancer Research. New Estimate: Excess Body Fat Alone Causes over 100,000 Cancers in US Each Year [http://www.aicr.org/site/News2/153571380?abbr=pr_&page=NewsArticle&id=17333&news_iv_ctrl=1102]
Chen WY, Rosner B, Hankinson SE, et al. Moderate alcohol consumption during adult life, drinking patterns, and breast cancer risk. JAMA 2011, 306:1884-1890.
Boyle P, Boffetta P. Alcohol consumption and breast cancer risk. Breast Cancer Res 2009, 11 Suppl 3:S3.
Kwan ML: Alcohol consumption and breast cancer recurrence and survival among women with early-stage breast cancer. In San Antonio Breast Cancer Symposium2009.
Velicer CM, Heckbert SR, Lampe JW, et al. Antibiotic use in relation to the risk of breast cancer. JAMA 2004, 291:827-835.
McDougall JA, Malone KE, Daling JR, et al. Long-term statin use and risk of ductal and lobular breast cancer among women 55 to 74 years of age. Cancer Epidemiol Biomarkers Prev 2013, 22:1529-1537.
Li CI, Daling JR, Tang MT, et al. Use of Antihypertensive Medications and Breast Cancer Risk Among Women Aged 55 to 74 Years. JAMA Intern Med 2013.
Largent JA, McEligot AJ, Ziogas A, et al. Hypertension, diuretics and breast cancer risk. J Hum Hypertens 2006, 20:727-732.