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Patty Guay-Berry, RD

We all have questions about what makes a healthy diet. Patty Guay-Berry, RD, an outpatient oncology dietitian at Adventist HealthCare Shady Grove Medical Center, answers your diet and nutrition questions.

Question: I have heard that soy foods are not safe if I have breast cancer. Is that true?

Guay-Berry: There seems to be a lot of confusion about the safety of soy foods, especially after a breast cancer diagnosis. Whole soy foods are actually safe to eat and may possibly be beneficial for people. In fact, whole soy foods while young and during adolescence appears to show a protective effect for breast cancer later in life.

Soy helps decrease levels of endogenous estrogen, which is linked to developing breast and ovarian cancer. A number of studies have shown that soy intake is associated with lowering the risk of breast cancer. Additionally, whole soy foods are beneficial for those with prostate cancer.

The reason that soy can help prevent cancer is because it contains something called isoflavones. This natural compound can inhibit certain enzymes that cause tumors to grow. Some people have the misunderstanding that soy foods contain too much estrogen and are dangerous to eat if you want to reduce your risk of breast cancer. This is actually incorrect. The chemical structure of the soy compound is similar to estrogen, but does not act like estrogen inside the human body.

What Soy is Best?

The type of soy consumed is important. Try these healthy, portioned whole soy food options.

  • ½-cup tofu
  • ½-cup tempeh
  • 1 tbsp. miso
  • ½-cup edamame
  • 1 cup unsweetened soy milk
  • ¼-cup soy nuts

Follow these tips to eat the healthiest soy products:

  • Choose organic soy foods
  • Stick to two servings per day
  • Avoid processed soy foods and protein powders

Not only are soy foods healthful, but choosing to add soy into one’s diet can help you eat enough protein to feel full and stay healthy, add variety to your diet and decrease the amount of meat you eat. Eating a plant based meal plan may help prevent some cancers and heart disease.

To find recipes and tips for preparing soy, visit www.aicr.org or www.meatlessmondays to find quick and easy ideas to prepare wholesome whole soy foods.


Want more help eating healthy? Make an appointment with a registered dietitian by calling 301-315-3129 for the Rockville office or 301-891-6105 for our Takoma Park office.