Breast Cancer

Recommendations for Breast Cancer Prevention from the World’s Leading Cancer Organizations

Modify your diet to decrease your risk of breast cancer

According to the World Health Organization (WHO), over 2 million women are diagnosed with breast cancer each year, leading to approximately 685,000 deaths. It is the most prevalent cancer in the world¹. Breast cancer can emerge from different parts of the breast when cells begin to grow at a quick and uncontrollable pace: 85% start in the tissue of the ducts, while 15% start in the lobules². Sometimes cancerous cells remain in their initial region, but other times they spread to a nearby lymph node or another organ. This spread is known as metastasis. Metastasis is the most common cause of breast cancer-related death¹. This article focuses on breast cancer in women.

Methods

The recommendations described in this article combine nutritional research gathered from some of the largest and most referenced breast cancer organizations worldwide. We also summarize each organization’s recommendations independently.

General Anticancer Eating Habits

For general cancer prevention, see our Cancer Fighting Food Recommendation Article that was created using a similar methodology, but for all cancers.

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Getting Started: Recommendations to Prevent Cancer: A large variety of colorful vegetables and fruits should be consumed daily. Whole grains and seeds should be consumed. Hydration is essential. Fiber and whole food consumption should take up a large percentage of daily intake. Red and processed meats should be limited to 12-18 ounces per week, if not avoided all together. Plant-based food consumption should be favored. Trans fats, foods high in fat, starches, and sugar should be limited or substituted with unsaturated fats and omega-3s. Alcohol should be avoided, but if consumed, it should be limited to 2 or fewer alcoholic beverages per week.

Overall Breast Cancer Prevention Nutritional Recommendations

Importantly, women who are trying to prevent breast cancer should maintain a healthy weight through both diet and exercise. Nutritionally, the most aggressive recommendations are 2 cups of fruit and 3 cups of vegetables per day. Women should consume 3 to 4 ounces of whole grains (men can consume up to 5 ounces) per day. 30 grams of fibre and 30 to 50 grams of flaxseed should be consumed daily. The United States Department of Agriculture recommends 7 ounces of protein per day³. Cooked red meat should be limited to 10.6 ounces (300 grams; ~1.325 cups) per week. Processed meat should be limited as much as possible. Less than 10% of calories should come from saturated fats (for a typical person, this would be approximately 0.8-1.1 ounces, or 22-30 grams, per day). Alcohol should be avoided entirely.

Explanation, Tips, and Examples

📄 Detailed Breast Cancer Prevention Notes by Anticancer.ca

Weight Management, Obesity, and Menopause: Gaining weight in adulthood is generally associated with an increased risk of breast cancer, both before and after menopause^4-6. If you are overweight, losing even a slight amount of weight can be beneficial. This can be accomplished through a change in diet or exercise⁷. Maintaining a healthy weight through diet and exercise is considered “best-practice” and is highly recommended^4,5.

Fruits and Vegetables: A key recommendation throughout the various breast cancer organizations is to eat fruits and vegetables consisting of a variety of colors³. The Susan G. Komen Foundation conducted an analysis where they pooled data from 20 studies and found that an increased consumption of vegetables is associated with a lower risk of estrogen receptor-negative breast cancer⁶.

Fibre: There is conflicting data when it comes to fibre, as some studies have found no link. However, a meta-analysis found that a higher-fibre diet is associated with a lower risk of breast cancer⁶.

Whole Grains: The National Breast Cancer Foundation explains that refined grains have a decreased amount of many nutrients in comparison to whole grains, such as fibre, minerals, iron, and vitamins. Check nutrition labels and ingredients: the first ingredient should be either “whole wheat”, whole grain”, or a food that is not refined (e.g., oats, oatmeal, or brown rice). If the product is a refined grain, labels and ingredients might state “enriched”, “fortified”, “wheat flour/germ,” or “bran”^3,8.

Seeds: Flaxseed was specifically described as containing lignan, which has the potential to bind to estrogen receptors to decrease cancer risk.

Dairy: Some studies associate dairy with a decreased risk of breast cancer; the potential association is due to high levels of calcium in dairy, which may have a protective effect against breast cancer^5,9. However, evidence that the consumption of dairy decreases breast cancer risk remains limited.

Meat: There is some conflicting data when it comes to red meat, as it can be a good source of iron for woman³. However, fish and poultry are the preferred meats for consumption^3,5. Processed meats are supposed to be limited or avoided.

Soy: There is no clear conclusion, although the American Cancer Society expresses that there might be a decrease in breast cancer risk with consumption⁵.

Sugar: The Susan G. Komen Foundation states that there has not been clarity with respect to a direct association; however, sugar does increase weight gain, which is associated with an increased risk of breast cancer⁶.

Alcohol: It is best to avoid alcohol, as even minimal consumption increases risk^4,6,7,10,11.

Summary

Recommendation	Amount	Explanation and Tips
Maintain a Healthy Weight	Gaining weight in adulthood can increase the risk of breast cancer. Weight loss can be beneficial if overweight. This can be achieved through diet and exercise.
Fruits and Vegetables	2 cups of fruit and 3 cups of vegetables per day	Consuming a variety of colorful fruits and vegetables may lower the risk of estrogen receptor-negative breast cancer.
Whole Grains	3-4 ounces per day	Whole grains have more nutrients than refined grains. The first ingredient in a product should be "whole wheat", "whole grain", or an unrefined food.
Fibre	30 grams per day	While data is conflicting, a high-fibre diet may be associated with a lower risk of breast cancer.
Flaxseed	30-50 grams per day	Flaxseed contains lignan, which can bind to estrogen receptors and potentially decrease cancer risk.
Protein	7 ounces per day	This is the USDA recommendation. Fish and poultry are preferred.
Red Meat	Less than 10.6 ounces per week	While red meat can be a good source of iron, it should be limited.
Processed Meat	As little as possible	Processed meats should be limited or avoided.
Saturated Fats	Less than 10% of daily calories (approx. 0.8-1.1 ounces or 22-30 grams per day)	High intake of saturated fats can increase risk of breast cancer.
Alcohol	None	Even the slightest consumption of alcohol can increase breast cancer risk.
Soy	No clear conclusion	American Cancer Society suggests there might be a decrease in breast cancer risk with soy consumption.
Sugar	No clear conclusion	Although there's no direct link, sugar can increase weight gain, which is associated with higher breast cancer risk.

When attempting to reduce the risk of breast cancer, there is a strong emphasis on maintaining a healthy weight and avoiding obesity after menopause. This can be accomplished through implementing lifestyle changes, such as choosing appropriate foods for prevention, and limiting or avoiding alcohol altogether. Studies suggest that if there is success in the implementation of lifestyle changes, 25 to 30 percent of breast cancer cases can be avoided¹². The diet and lifestyle recommendations are in accordance with the majority of organizations’ recommendations for overall health and anti-aging benefits, general cancer prevention, and personalized prevention plans.

To have your institution recommendations included or to modify the recommendations presented from your institution email info@anticancer.ca.

Subscribe for future work that will include recommendations for other specific cancers. We will also feature the reasoning and evidence behind certain recommendations, and reviews of primary research papers and randomized clinical controlled trials that investigate specific nutrients and supplements.

Frequently Asked Questions

Generally, yes, these nutrition guidelines are useful even if you already have breast cancer. Studies show that healthy eating habits can complement your medical treatment and help you in the fight against cancer. You should consult with a health professional and your specific breast cancer treatment team.

Different experts may focus on different studies, clinical trials, peer reviewed studies, or other scientific references. They may place emphasis on data that was performed at their specific institute, so they know that it is reliable. Even when experts focus on the same studies, clinical trials, and peer reviewed sources, the interpretation of the data could be different. Scientific interpretation is often influenced by an individual’s specific background and experiences, as well as how restrictive they decide to make their recommendations. Thus, our compilation has minimal and aggressive recommendations a simple guide for you to follow to make sure you have your bases covered.

We began with the largest breast cancer institutions and societies but have slowly incorporated additional information. Not all institutions/societies have information for every category.

These are foods that have been shown through scientific research to reduce cancer risk. These foods that fight cancer should NOT be a substitute for any cancer fighting treatment, such as treatment used to reduce tumor growth or to stop cancer cells, from a licensed medical professional. Instead, these foods should complement your cancer fighting strategy. They provide potential health benefits and reduced risk.

Yes, there are specific examples as discussed in the article above. In addition, you may wish to consult our Cancer Fighting Food Recommendation Article. In terms of vegetables and fruits, leafy green vegetables should be consumed and in addition the more variety of colours that are consumed in diet, the more variety of phytonutrients that the body absorbs. It is recommended that whole foods are preferred over seeking nutrients from supplements such as beta carotene, folic acid, and vitamin C. A diet rich in these nutrients is more beneficial than eating the supplements themselves. Whole foods are always preferred over any form of processed foods, especially in terms of processed meat. Future articles will discuss randomized controlled trials and evidence for specific nutrients. Remember: do NOT use nutrition to substitute for any cancer fighting treatment recommendations from a licensed medical professional. Instead, these foods that fight cancer should complement your cancer fighting strategy.

Whole foods are preferred over supplements; we will have future articles discussing possible supplementation.

Medical and dietary restrictions come first. The cancer fighting recommendations are generally flexible and allow for a variety of choices to adapt to your needs. For cancer fighting meal examples that might fit your personal restrictions, see our personalized meal planner.

No. Cancer is a complex disease. Research papers often evaluate the effects of different chemicals on cancer cells grown on a dish at much higher concentrations that can be safely achieved in the human body. Further, there are many differences between cancer cells of the same type, and even differences among the different cancer cells within the same person.

References

Breast cancer. Accessed February 16, 2023. https://www.who.int/news-room/fact-sheets/detail/breast-cancer
CDCBreastCancer. What Is Breast Cancer? Centers for Disease Control and Prevention. Published March 9, 2022. Accessed February 16, 2023. https://www.cdc.gov/breast-cancer/index.html
Understanding Food Groups. Accessed February 27, 2023. https://www.breastcancer.org/managing-life/diet-nutrition/what-does-healthy-eating-mean/food-groups
Cancer Prevention Recommendations. WCRF International. Accessed December 20, 2022. https://www.wcrf.org/diet-activity-and-cancer/cancer-prevention-recommendations/
American Cancer Society Guideline for Diet and Physical Activity. Accessed January 12, 2023. https://www.cancer.org/healthy/eat-healthy-get-active/acs-guidelines-nutrition-physical-activity-cancer-prevention/guidelines.html
Diet and Breast Cancer. Susan G. Komen®. Accessed February 16, 2023. https://www.komen.org/breast-cancer/risk-factor/diet/
Breast Cancer. Cancer Care Ontario. Published June 28, 2017. Accessed February 16, 2023. https://www.cancercareontario.ca/en/types-of-cancer/breast-cancer
National breast Cancer Foundation. Nutrition Care for Cancer Patients.
Diet, nutrition, physical activity and breast cancer. Published online 2017.
Lee S. Risks for breast cancer. Canadian Cancer Society. Accessed February 16, 2023. https://cancer.ca/en/cancer-information/cancer-types/breast/risks
Breast cancer: How to reduce your risk. Mayo Clinic. Accessed February 27, 2023. https://www.mayoclinic.org/healthy-lifestyle/womens-health/in-depth/breast-cancer-prevention/art-20044676
Harvie M, Howell A, Evans DG. Can diet and lifestyle prevent breast cancer: what is the evidence? Am Soc Clin Oncol Educ Book Am Soc Clin Oncol Annu Meet. Published online 2015:e66-73. doi:10.14694/EdBook_AM.2015.35.e66

About This Article

First Published	April 10, 2023
Last Updated	April 10, 2023
Author	Ashiana Sunderji
Fact Checkers and Co-Authors	Aria Panchal and Courtney Leung
Reviewer and Supervisor	Kenneth W. Yip

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