Eating well after breast cancer

Eating a healthy, well-balanced diet can help your body recover from and cope with the side effects of treatments for breast cancer. Talk to your healthcare team if you have questions about the following and how they might affect you.

Diet and breast cancer recurrence

A healthy, well-balanced diet includes plenty of vegetables and fruit and limits meat and fat. Following this diet can lower your risk for several types of cancer, including breast cancer. It can also help lower your risk for other diseases such as diabetes or heart disease.

There isn't enough evidence yet to say that a specific diet or certain foods can lower the risk that cancer will come back. There is also very little evidence that suggests that you should not eat certain foods because they increase the risk that breast cancer will come back.

Find out more about eating well after cancer treatment.

Body weight and breast cancer survival

Some women lose weight during treatment for breast cancer because of the side effects of treatments, such as chemotherapy. Being underweight can increase your risk for complications during treatment and affect your quality of life.

Other women gain weight during certain treatments, such as hormonal therapy. You may also gain weight because you aren't as physically active as you normally would be. Growing evidence shows that breast cancer survivors who are overweight or obese have a less positive prognosis and don't live as long as survivors who are at a healthy weight.

Maintaining a healthy body weight will help you recover from breast cancer and its treatments. Eating a healthy diet and being physically active can help you get to and keep a healthy body weight. Talk to your healthcare team. They can refer you to a dietitian or an exercise specialist to help you.

Find out more about a healthy body weight.


Some breast cancer cells are hormone-receptor positive. This means that they can use estrogen normally found in your body to grow and divide. Soy contains chemicals called phytoestrogens. Some breast cancer survivors worry that the phytoestrogens in soy may act like estrogen and will make their cancer grow or come back after treatment.

Most of the current evidence suggests that the soy taken in as part of a healthy, well-balanced diet is unlikely to harm breast cancer survivors. Other studies suggest that eating soy foods may help improve breast cancer survival, especially in post-menopausal women.

Soy is a protein that comes from soybeans. Soy-based foods include tofu, soy milk, soybeans, soy nuts and miso. Soy-based foods are better and healthier than other sources of soy, including soy protein powders, pills and other soy supplements. You can eat up to 3 servings of soy-based foods each day.

Dietary and herbal supplements

Some people think that they need to take vitamin, mineral or herbal supplements to help lower the risk that the cancer will come back after treatment. But a healthy, well-balanced diet is the best way to get the nutrition you need.

Check with your healthcare team before you take any supplements. They can do tests to see if you aren't getting the nutrition you need from your diet. They can also tell you which types of supplements are safe for you and how much you should take. Large doses of some vitamins and minerals can be harmful. They may also interact with prescription drugs, over-the-counter medicines or cancer treatments. Some herbal supplements can also interfere with medications or cancer treatments.


Antioxidants are chemical substances found in many foods. They can protect cells in your body by removing free radicals. Free radicals are made when our bodies use oxygen during normal cell function. They are unstable molecules that easily react with other molecules. Free radicals can damage cells, which may lead to cancer.

Vitamin C, vitamin E, beta carotene and selenium are antioxidants found in many foods, especially vegetables and fruit. The best way of getting antioxidants for our bodies is eating a healthy diet, rather than taking pills or supplements.

Talk with your healthcare team before taking antioxidant supplements during breast cancer treatment. They can tell you which types of supplements are safe for you and how much you should take. It's important that your healthcare team knows about any supplements you take.

Expert review and references

  • Bradshaw PT, Ibrahim JG, Khankari N, Cleveland RJ, Abrahamson PE, Stevens J, Satia JA, et al . Post-diagnosis physical activity and survival after breast cancer diagnosis: the Long Island Breast Cancer Study. Breast Cancer Research and Treatment. 2014.
  • Chi F, Wu R, Zeng YC, Xing R, Liu Y, Xu ZG . Post-diagnosis soy food intake and breast cancer survival: a meta-analysis of cohort studies. Asian Pacific Journal of Cancer Prevention. 2013.
  • de Glas NA, Fontein DB, Bastiaannet E, Pijpe A, De Craen AJ, Liefers GJ, Nortier HJ, et al . Physical activity and survival of postmenopausal, hormone receptor-positive breast cancer patients: results of the Tamoxifen Exemestane Adjuvant Multicenter Lifestyle study . Cancer . 2014 .
  • Lahart IM, Metsios GS, Nevill AM, Carmichael AR . Physical activity, risk of death and recurrence in breast cancer survivors: A systematic review and meta-analysis of epidemiological studies. Acta Oncologica. 2015.
  • Nechuta SJ, Caan BJ, Chen WY, Lu W, Chen Z, Kwan ML, Flatt SW, et al . Soy food intake after diagnosis of breast cancer and survival: an in-depth analysis of combined evidence from cohort studies of US and Chinese women. American Journal of Clinical Nutrition. 2012.
  • World Cancer Research Fund International & American Institute for Cancer Research . Continuous Update Project Report: Diet, Nutrition, Physical Activity and Breast Cancer Survivors . 2014 .

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

We do our best to make sure that the information we provide is accurate and reliable but cannot guarantee that it is error-free or complete.

The Canadian Cancer Society is not responsible for the quality of the information or services provided by other organizations and mentioned on, nor do we endorse any service, product, treatment or therapy.

1-888-939-3333 | | © 2024 Canadian Cancer Society