Q&A: How diet affects breast cancer risk and outcomes

Previous research has demonstrated associations between nutrition and breast cancer.

For example, studies have shown that, for postmenopausal women, adhering to a healthy plant-based diet was linked to a 14% lower risk for breast cancer, and that diets promoting inflammation might increase breast cancer risk.

In recognition of Breast Cancer Awareness Month, Healio spoke with Adi Benito, MD, an integrative endocrinologist at Princeton Integral Endocrinology and chief medical advisor of the nonprofit Eating for Your Health, to learn more about the associations between diet and breast cancer.

Benito, who is board-certified in diabetes, metabolism and endocrinology, discussed the connections between breast cancer and diet, primary care providers’ nutrition misconceptions and more.

Healio: Why is eating foods rich in anti-inflammatory compounds critical after a breast cancer diagnosis?

Benito: Breast cancer is considered a condition of increased oxidative stress (inflammation). Anti-inflammatory compounds in foodstuffs, such as carotenoids, polyphenols and omega-3 fatty acids, have been found to decrease the risk of breast cancer recurrence, and mortality from breast cancer.

Healio: Which specific foods and food compounds are beneficial to those diagnosed with breast cancer?

Benito: Carotenoids, polyphenols, fiber and omega-3 fatty acids.

Carotenoids are bright red, yellow and orange pigments in fruits and vegetables. Pumpkins, carrots, tomatoes, collards, tangerines, winter squash, cantaloupes, mangoes, papaya, sweet potatoes, watermelon, guava, grapefruit, asparagus, red cabbage, red bell peppers, but also spinach, kale, parsley and peas contain carotenoids.

Polyphenols are a large and diverse family of plant pigments, considered antioxidants. There is ongoing research on the anticancer activity of the polyphenol family.

Fiber is anti-inflammatory, improves gut immune function, and may reduce breast cancer risk recurrence and mortality.

Healio: What foods can primary care physicians recommend to help prevent breast cancer in patients who are at high risk?

Benito: A plant-based diet, including vegetables and fruits, nuts and seeds (in particular, flax seeds), herbs and spices, legumes (beans and lentils), whole grains and if feasible, one that incorporates marine sources of omega-3 fatty acids. Carotenoids, polyphenols, fiber, and omega-3 fatty acids have been associated with a lower risk of breast cancer. Of the polyphenols, flavonols have been found to decrease breast cancer risk in several studies. Flavonols are found in onions, leeks (and other alliums), kale, rosemary, broccoli, cherry tomatoes, blueberries, beans, apricots and tea.

Healio: What are some common misconceptions among PCPs about nutrition?

Benito: The role of nutrition in breast cancer prevention is likely underappreciated by many physicians. In the field of obesity, “calories in-calories out” has been the approach to weight gain, but this model does not take into account metabolic adaptation.

Healio: Is there anything else you’d like to add?

Benito: Breast cancer survivors and those at risk for breast cancer should strongly consider decreasing/avoiding added sugars and a diet rich in plain carbohydrates, because they increase the risk of breast cancer. Adding fiber-rich foods lowers this risk.