By Dr Malcolm Mackay

Heart disease is the leading cause of death in breast cancer survivors. A whole foods, plant-based diet, low in fat, is the only diet that has been proven to reverse heart disease.

There is a substantial body of evidence for the role of diet and lifestyle on breast cancer risk and breast cancer survival. Some of this data is observational – eg. women who eat soy have less chance of recurrence; some is from laboratory work – eg. blood from women on plant-based diets is more effective at killing breast cancer cells in a petri dish, and other evidence comes from research on other hormone driven cancers – eg. a randomised controlled trial found that the progression of prostate cancer could be stopped with a plant-based diet and lifestyle program. There are reasonable grounds to assume that most factors that affect the risk of getting breast cancer have a similar effect on the risk of recurrence or progression of established breast cancer. There are several studies underway investigating the effect of a whole foods, plant-based diet on women with breast cancer. You do not have to wait for the results before taking action as all of the strategies we suggest have side benefits rather than side effects and are compatible with conventional medical therapy.

Nutrition research often focusses on the effects of individual foods on breast cancer, and this guide will mention some of these, however, the whole is greater than the sum of the parts and our approach is more a whole diet and lifestyle approach than an ingredients list of special cancer fighting foods.

Some of the observed associations between nutrition and cancer are backed up by our understanding of the mechanisms that promote or inhibit cancer. Animal protein promotes cancer development at all stages, from the initial mutation though to cancer progression years or decades later. Some of the cancer promoting effects of meat and dairy are thought to be due to stimulation of growth regulating systems like the hormone IGF-1 produced by the liver and the cellular growth regulator, mTOR. Excess oestrogen caused by dietary and lifestyle factors promotes growth, particularly in the breast and reproductive organs. The more we study the phytonutrients in plants (substances that are not ‘essential nutrients’ but are essential for good health) the more mechanisms we discover that protect against and inhibit cancer growth.

Excess oestrogen contributes to many women’s health problems including breast cancer. Many breast cancers are oestrogen positive (have receptors for oestrogen and grow more when exposed to oestrogens). Breast cancer hormonal therapy aims to block this effect. However, there are also dietary and lifestyle factors that can reduce oestrogen.

Strategies to reduce oestrogen:

• Don’t eat other animal’s oestrogens (dairy foods, chicken, eggs)
• Reduce exposure to oestrogen-like chemicals (eat from the bottom rung of the food chain – plants, not fish, buy organic if you can)
• Increase oestrogen excretion by eating more dietary fibre (esp. flaxseed)
• Block some of the effects of oestrogen with plant phytoestrogens (eg. soy)
• Limit dietary fat intake (oils, nuts and seeds)
• Exercise
• Maintain a lean body (fat cells make oestrogen)
• Avoid alcohol (blocks oestrogen deactivation in the liver)
• Limit caffeine (increases oestrogen levels)

Dietary Guidelines for Breast Cancer Survivors:

• Eat a whole foods, plant-based diet:
  • Make whole grains, starchy vegetables, and legumes your main source of calories rather than nuts and seeds
  • Use only whole grains at home, preferably more intact forms rather than flour products
• Use no oil in home cooking, not even olive oil or coconut oil
• Include phytonutrient-rich foods with every meal
  • Berries, mushrooms, garlic and onion, spices
  • Green leafy vegetables are superfoods – eat them in abundance several times per day
  • Cruciferous vegetables* – broccoli, cauliflower, cabbage, bok choy, rocket (arugula) etc

* When cruciferous vegetables are chewed, crushed or chopped (while raw) an enzyme produces sulphoraphane. The enzyme is destroyed by cooking but not the sulphoraphane. Methods to increase sulphoraphane content include: eating it raw, adding some raw cruciferous (or mustard seed) to the cooked cruciferous, or leaving chopped cruciferous to stand before cooking. Broccoli sprouts are extremely high in sulphoraphane and are easy to grow in your kitchen.

• Include a tablespoon of ground flaxseed (available at supermarkets) in your daily diet
• Keep salt intake low for immune health and cardiovascular health
  • High salt foods include bread and many condiments
• Get your nutrients from food, not supplements except for:
  • Vitamin B12, Vitamin D if you lack sun exposure
• Avoid alcohol – even one drink per day increases breast cancer risk significantly
• Limit caffeinated beverages

Raw vs cooked:

There are some nutrients that are more available in raw foods and some in cooked foods. Most nutrients and phytonutrients survive cooking. Totally raw food diets exclude some of the healthiest food groups (whole grains, legumes), reduce food diversity, reduce the volume of vegetables eaten (leafy greens, broccoli etc), and are often inadequate in total calories and relatively high in fat (nuts, seeds, oils provide most of the calories). Include cooked whole grains and legumes in your diet.

Gut microbiome:

The health of the body begins in the gut with the microbiome. If you feed your microbiome well with high fibre, starchy foods like legumes and minimally processed grains, it will repay you with post-biotics like short chain fatty acids. These microbial products regulate the immune system, reduce inflammation, improve metabolic health, keep you slim and even improve brain health.

Other lifestyle factors:

Exercise downregulates growth promoting hormones – oestrogen, IGF-1 and insulin – and is associated with lower breast cancer risk. Cancer remission testimonials often include a high level of physical activity in addition to a healthy plant-based diet. Sleep too, has been shown to boost immune function while lack of sleep has been associated with increased breast and bowel cancer. A healthy mind, stress optimisation and positive social interactions support physical health including an effective cancer fighting immune system. Lastly, purpose in life, and having a personal ‘why’ for a longer healthier life, seems to be an attribute of extraordinary cases of cancer survival.

Resources

• See Breast Cancer Resources

Return to Breast Cancer page

Page created 28 June 2020
Page last updated 28 June 2020

There has been a lot of bad press about soy – cancer scares, phytoestrogen concerns, GM fears, anti-nutrient effects and thyroid problems to name a few. Negative articles and blog posts can often be traced back to particular organisations with links to the meat and dairy industries. They are either completely unsupported by published research or else based on small pieces of information taken out of context. Nonetheless, bit by bit, the vague idea that soy is “unhealthy” and has “hormone-like side effects” has become a social contagion infecting the public and even health professionals (who should be basing their advice on scientific evidence not blog posts or newspaper articles).

Traditional soy foods have been consumed in Asia for thousands of years. They include tofu, tempeh, edamame, miso and soy milk. These were added to rice-based meals as condiments rather than being the central feature of the meal, which is often the case when one orders a tofu dish at an Australian restaurant.

Our food industry has created many highly processed meat, egg and dairy ‘replacement’ foods out of soy protein. There are also soy based ‘protein’ bars and ‘protein’ shakes. These processed foods often have added salt, sugar and fat and may provide unnaturally large amounts of soy protein. However, there is some merit in these products as a means of providing meat-like foods to consumers without the heavy environmental impact of animal agriculture.

The truth about soy:

• The consumption of traditional soy products is associated with lower risks of a number of diseases including breast and prostate cancers.
• The phytoestrogens in soy have both weak estrogenic effects and anti-estrogen effects. Soy products do not feminize males and soy phytoestrogens, even when artificially concentrated, are not strong enough to be effective hormone replacement therapy in post-menopausal women. Ironically, cow’s milk contains significant amounts of real full strength cow estrogens.
• Genetically modified soy is not an issue in Australia if you are eating a whole food plant-based diet. Most GMO soy crops are fed to livestock. Foods in Australia with GM ingredients must be labelled as such, although if they are in highly refined ingredients (e.g. oils) they may not be – but we don’t recommend processed foods with highly refined ingredients. It is easy to buy soy milk, tofu and tempeh that is clearly labelled non-GMO.
• Soy products do not significantly inhibit the absorption of iodine or other minerals.
• Very high intakes of soy protein may have similar adverse effects to consuming animal protein. For example causing elevated levels of IGF-1, the cancer and acne promoting hormone.
• Soy beans (along with peanuts) have a much higher fat content than the other legumes.

Recommendations:

• It is not necessary to include soy foods in your diet, but they can be a health supporting addition to a whole foods plant based diet along with other legumes.
• Choose mainly traditional soy products such as edamame, tofu or tempeh and use them as an accompaniment or condiment to starches and vegetables rather than making them the focus of your meal.
• Soy milk should be based on whole soy beans (check the carton as some brands are not) and only used as an ingredient or as an addition to hot drinks or cereals. There is no need to drink soy (or any other milk) by the glassful as once weaned humans have no nutritional need to consume milk.
• Avoid heavily processed foods containing isolated soy protein (e.g. soy chips, soy burgers and soy-based protein supplements).
• If you are trying to lose weight then be aware that soy beans (and peanuts) are higher in fat than other legumes and so it would be wise to eat less of them.

Resources

• No Debate: Soy is Beneficial to Health – Dr Neal Barnard, March 2016
• Putting Soy Consumption in Perspective – Jeff Novick, R.D., April 2014
• Don’t Fall for the Myths About Soy  – Dr Joel Fuhrman. See also this 2 min. video
• Do cruciferous vegetables or soybeans harm the thyroid? – Dr Joel Fuhrman
• Soy and Health – PCRM
• The Truth About Soy – John Robbins, Dec. 2012
• The Truth About Soy – (video) Dr John McDougall
• Soy – Food, Wonder Drug, or Poison? – Dr John McDougall, April 2005
• How Much Soy Is Too Much? – Dr Michael Greger, Feb. 2013
• Is Soy Healthy for Breast Cancer Survivors? – (5 min video) Dr Michael Greger
• Can soy suppress thyroid function? – Dr Michael Greger
• Finally, the Truth About Soy – Leo Babauta

Peer-reviewed articles:

• Applegate, C. C., Rowles, J. L., Ranard, K. M., Jeon, S., & Erdman, J. W. (2018). Soy Consumption and the Risk of Prostate Cancer: An Updated Systematic Review and Meta-Analysis. Nutrients, 10(1), 1-25.
• Dewell, A., Weidner, G., Sumner, M. D., Barnard, R. J., Marlin, R. O., Daubenmier, J. J., . . . Ornish, D. (2007). Relationship of dietary protein and soy isoflavones to serum IGF-1 and IGF binding proteins in the Prostate Cancer Lifestyle Trial. Nutrition & Cancer, 58(1), 35-42.
• Hamilton-Reeves, J. M., Vazquez, G., Duval, S. J., Phipps, W. R., Kurzer, M. S., & Messina, M. J. (2010). Clinical studies show no effects of soy protein or isoflavones on reproductive hormones in men: results of a meta-analysis. Fertility and Sterility, 94(3), 997-1007.
• Messina, M. (2014). Soy foods, isoflavones, and the health of postmenopausal women. American Journal of Clinical Nutrition, 100 Suppl 1, 423S-430S.
• Messina, M. J., & Wood, C. E. (2008). Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary. Nutrition Journal, 7, 17.
• Shu, X. O., Zheng, Y., Cai, H., Gu, K., Chen, Z., Zheng, W., & Lu, W. (2009). Soy food intake and breast cancer survival. JAMA, 302(22), 2437-2443.

 

Page created 2 August 2014
Last updated 7 June 2023

“Lifestyle choices may increase or decrease the risk of breast cancer, but that knowledge is an opportunity to empower ourselves, not to blame” – Dean Ornish, MD.

• Nutrition for breast cancer survival
• Resources
• Success stories

Breast cancer evokes more fear than cardiovascular disease, even though cardiovascular disease is the leading cause of death in women. Perhaps it’s because breast cancer seems more random and often strikes at an earlier age. Observational studies have found many dietary factors to be associated with an increase or decrease in long term breast cancer mortality.

The following resources are intended to empower women to reduce their life-time risk of dying from breast cancer. It is not our intention to explain why anyone has developed breast cancer as such thinking can lead to blame and guilt – we think this is the reason why health organisations and specialists are reluctant to tell women what dietary changes will reduce their risk.

Prevention
The association between the Western diet and breast cancer has been known for many years.

This classic graph of breast cancer vs fat intake shows a wide variance in breast cancer risk between countries, demonstrating that that rising breast cancer risk with age is not inevitable.

This graph probably tells a much broader story, the fat intake being a marker for an increased intake of animal products and a reduced intake of whole plant foods. There are other lifestyle factors: breast cancer risk is increased by early puberty, obesity and alcohol; and decreased by younger age of first pregnancy, breast feeding and exercise. Studies of migrant populations prove that genes do not explain the variation between countries.

By late middle age, most women will have breast micro-cancers. At this stage, and probably at a much earlier age, the strategies we present to help you to prevent breast cancer might actually be regarded as “treatment” to keep those cancers micro-sized.

Screening
It may surprise some of you that there is a great deal of controversy about whether breast screening mammography is beneficial. There are several points to be made:

• Earlier discovery of breast cancer will only sometimes change the long term outcome
• As many as a third of breast cancers found by screening programs would not have progressed to clinical disease
• Many women are physically and mentally harmed by further investigation and treatment of false positive results – lesions that turn out not to be breast cancer.

The video by Goetsch gives an excellent overview of this: Peter Gøtzsche, MD: Director of The Nordic Cochrane Centre: Part 1: Recommends against mammography and prostate cancer screening

The decision on whether or not to undergo breast screening is a personal one. Most doctors would recommend screening for women considered to be at greatly increased risk.

Treatment
Conventional treatments include surgery, radiotherapy, chemotherapy and long-term hormonal treatment. The benefits of some of these therapies may be overstated. It is important to ask your oncologist what the absolute risk reduction is for the particular treatment, i.e. the likelihood that an individual will avoid premature death. A low-fat, high-fibre plant-based diet has been shown to improve overall survival following breast cancer diagnosis (McEligot et al 2006; Xing et al 2014). The evidence is strong enough such that it should be routine to recommend a whole foods plant-based diet alongside conventional cancer treatment. It should be appreciated that cancer survivors are at increased risk of other diseases, especially heart disease – which can be prevented with a whole foods plant-based diet.

There are many case reports of prolonged remission of advanced breast cancer through adoption of a whole foods plant-based lifestyle. Randomised controlled trials have demonstrated that low to medium grade prostate cancer can be treated with diet alone, but similar trials have not been conducted for breast cancer (for ethical reasons). We look forward to future trials which will investigate the impact of a whole foods, plant-based diet on breast cancer survival, although we note that the prostate cancer research findings have been ignored.

While medical experts are waiting for “gold standard” randomised controlled trials before they make any dietary recommendations for breast cancer, we consider there is enough evidence to act now. The side effects of a whole food plant-based diet are all good – improved overall wellness and ability to cope with treatment protocols, prevention and reversal of other chronic diseases and empowerment to take control of your destiny. With this in mind we have written a guide to Nutrition for Breast Cancer Survival.

See also:

• Nutrition for breast cancer survival
• Women’s Health
• Are soy products healthy?
• Our main Cancer page

Resources

Books

• Funk, K. (2018). Breasts: the owner’s manual :every woman’s guide to reducing cancer risk, making treatment choices, and optimizing outcomes. Nashville, Tennessee: Thomas Nelson.

Web links:

• Dietary Fats May Raise Ovarian Cancer Risk – Dr Linda Carney
• For Breast Cancer: It’s Not Nature vs. Nurture—It’s Both – Dr Dean Ornish (2014)
• Research Shows That a Healthy Diet Will Slow or Stop Most Cancers
  – John McDougall (2015)
• Breast Cancer – Dr John McDougall. This page links to numerous newsletter articles about detection, prevention and treatment of breast cancer
• Breast Cancer: Fight Breast Cancer with a Plant-Based Diet – PCRM
• Dr Michael Klaper On Cancer
• Breast Cancer: Fight Breast Cancer with a Plant-Based Diet – PCRM
• Plant-Based Foods Increase Breast Cancer Survival – PCRM
• Diet, Nutrition, Physical Activity, and Breast Cancer Survivors (2014) – World Cancer Research Fund International
• Stool Size and Breast Cancer Risk – (blog) Dr Michael Greger
• Breast Cancer and Diet – (blog) Dr Michael Greger
• Breast Cancer: Food, Prevention, Survival – PCRM Exam Room Podcast interview with Dr Neal Barnard (1hr 23 min)

Videos:

• Dr. Kristi Funk – Arm Yourself with Plant Warfare Against Breast Cancer – (36 min. video. 2021) Listen to breast cancer surgeon Dr Kristi Funk’s lively and informative 36 min presentation from the Esselstyn’s ‘Plant-Stock’ event on the PLANTSTRONG podcast with Rip Esselstyn
• Diet in the Prevention and Treatment of Common Cancers – (56 min video) John McDougall, MD. Presentation at the March 2015 Advanced Study Weekend
• Breast Cancer Treatment – John McDougall, MD
• Dietary Treatment of Cancer – John McDougall, MD
• Breast Cancer, Secret the Health Industry Doesn’t Want You to Know, Webinar: 10/29/15 – Dr John McDougall (50 min. video)
• Director of The Nordic Cochrane Centre: Part 1: Recommends against mammography and prostate cancer screening – Peter Gøtzsche, MD
• Cancer Treatment – Dr Pam Popper discusses the inflated benefits of cancer treatments (7 min. video)
• NutritionFacts.org summary of breast cancer videos (more than 60 videos), some of the best are listed below:
  • Fiber Vs. Breast Cancer – and follow the series by clicking Next Video.
  • Which Dietary Factors Affect Breast Cancer Most?
  • Slowing the Growth of Cancer
  • Ex Vivo Cancer Proliferation Bioassay
  • Relieving Yourself of Excess Estrogen
  • IGF-1 as One-Stop Cancer Shop
  • Breast Cancer Survival Vegetable
  • Exercise & Breast Cancer NB link broken; awaiting an update from NutritionFacts.org

Peer-reviewed articles:

• Aubertin-Leheudre, M., Hamalainen, E., & Adlercreutz, H. (2011). Diets and hormonal levels in postmenopausal women with or without breast cancer. Nutrition and Cancer, 63(4), 514-524.
• Bahadoran, Z., Karimi, Z., Houshiar-Rad, A., Mirzayi, H.-R., & Rashidkhani, B. (2013). Dietary phytochemical index and the risk of breast cancer: a case control study in a population of Iranian women. Asian Pacific Journal of Cancer Prevention, 14(5), 2747-2751.
• Barnard, R. J., Gonzalez, J. H., Liva, M. E., & Ngo, T. H. (2006). Effects of a low-fat, high-fiber diet and exercise program on breast cancer risk factors in vivo and tumor cell growth and apoptosis in vitro. Nutrition and Cancer, 55(1), 28-34.
• Bodai, B. I., & Tuso, P. (2015). Breast cancer survivorship: a comprehensive review of long-term medical issues and lifestyle recommendations. Permanente Journal, 19(2), 48-79.
• Endogenous Hormones and Breast Cancer Collaborative Group, Key, T. J., Appleby, P. N., Reeves, G. K., & Roddam, A. W. (2010). Insulin-like growth factor 1 (IGF1), IGF binding protein 3 (IGFBP3), and breast cancer risk: pooled individual data analysis of 17 prospective studies. [Meta-Analysis]. Lancet Oncology, 11(6), 530-542.
• Hastert, T. A., Beresford, S. A., Patterson, R. E., Kristal, A. R., & White, E. (2013). Adherence to WCRF/AICR cancer prevention recommendations and risk of postmenopausal breast cancer. Cancer Epidemiology, Biomarkers and Prevention, 22(9), 1498-1508.
• Kroenke, C. H., Kwan, M. L., Sweeney, C., Castillo, A., & Caan, B. J. (2013). High- and low-fat dairy intake, recurrence, and mortality after breast cancer diagnosis. Journal of the National Cancer Institute, 105(9), 616-623.
• McEligot, A. J., Largent, J., Ziogas, A., Peel, D., & Anton-Culver, H. (2006). Dietary fat, fiber, vegetable, and micronutrients are associated with overall survival in postmenopausal women diagnosed with breast cancer. Nutrition and Cancer, 55(2), 132-140.
• Messina, M. J., & Wood, C. E. (2008). Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary. Nutrition Journal, 7, 17.
• Nomura, S. J. O., Hwang, Y. T., Gomez, S. L., Fung, T. T., Yeh, S. L., Dash, C., . . . Wang, J. H. (2018). Dietary intake of soy and cruciferous vegetables and treatment-related symptoms in Chinese-American and non-Hispanic White breast cancer survivors. Breast Cancer Research and Treatment, 168(2), 467-479.
• Shu, X. O., Zheng, Y., Cai, H., Gu, K., Chen, Z., Zheng, W., & Lu, W. (2009). Soy food intake and breast cancer survival. JAMA, 302(22), 2437-2443.
• Xing, M.-Y., Xu, S.-Z., & Shen, P. (2014). Effect of low-fat diet on breast cancer survival: a meta-analysis. Asian Pacific Journal of Cancer Prevention, 15(3), 1141-1144.

Success stories

• After Breast Cancer, a Plant-Based Diet Gave Me a New Lease on Life – Teri Carpenter (2018)
• Patty’s Plant-Based Health Story (2015) See also this interview: Nutrition for Breast Cancer – Interview with Cancer Survivor Patty Falo
• Jessica Bowen: My Winning Battle with Breast Cancer (15 min video plus written story)
• Cancer-Free without Chemo … Thanks to Dr. McDougall and Forks Over Knives – Kelly Binkoski (2013)
• Ruth Heidrich: Defeats Cancer and Osteoporosis, Breast Cancer
• Anneliese Moore: Breast Cancer Treated with Diet

Page created 30 November 2013
Last updated (resources) 20 April 2019