Soy Consumption and Breast Cancer Risk

Evidence on Soy and Breast Cancer Risk

Current evidence suggests that moderate soy consumption (up to three servings per day of whole soy foods) is not linked to increased breast cancer risk and may even be associated with reduced risk of breast cancer recurrence, as recommended by the American Cancer Society 1, 2
Soy foods contain isoflavones that have both estrogenic and antiestrogenic effects, which has led to conflicting results in studies examining their relationship with breast cancer, according to the American Cancer Society 3, 4
The interest in soy's potential cancer-preventive properties stems from observations that Asian countries with high soy consumption have lower breast cancer rates than Western countries, as noted by the American Cancer Society 4, 5

Moderate soy consumption (consistent with amounts in a typical Asian diet) appears safe and potentially beneficial, as stated by the American Cancer Society 4, 5
Higher doses of soy may have estrogenic effects that could potentially increase the risk for breast cancer progression, as warned by the American Cancer Society 4, 6
Whole soy foods (tofu, soy milk, edamame) appear to be safe, according to the American Cancer Society 4, 7
Concentrated sources of soy isoflavones (soy powders, isoflavone supplements) should be avoided, especially by breast cancer survivors, as advised by the American Cancer Society 4, 6

Moderate consumption of whole soy foods (up to three servings daily) appears safe and may be beneficial for breast health, as recommended by the American Cancer Society 4, 6
Avoid concentrated soy supplements, especially if you have a history of breast cancer or a family history of breast cancer, as advised by the American Cancer Society 4, 8