Reducing Breast Cancer Risk Through Phytonutrients

Updated: Feb 7

Guest post by Kara Moore, dietetic intern, Georgia State University's Coordinated Program for Dietetics

If you're not convinced that eating more plant-based foods may help to reduce your risk of breast cancer from parts one and two of our three-part series on plant-based eating for breast breast, then keep reading. Part three, how plant-specific nutrients may help reduce breast cancer risk, takes a deeper dive into why adding more plant-based foods to your plate may mitigate the risk of breast cancer.

Phytonutrients, nutrients specific to only plants, are beneficial to human health, in part due to their antioxidant properties. Antioxidants prevent cellular damage, which may reduce the risk of cancer, heart disease, stroke, Alzheimer’s disease, and Parkinson’s disease. Because phytonutrients are exclusive to plants, the best way to include them is through colorful vegetables and fruits, whole grain products, nuts and seeds, legumes, tea, and dark chocolate.

Recent research has evaluated the anti-carcinogenic effects of the bioactive compounds in phytonutrients. Some of the bioactive compounds that have been researched include curcumin (found in turmeric), myricetin (found in berries, nuts, herbs), geraniin (found in berries, pomegranates, walnuts), and tocotrienols (found in rice bran, barley, whole grains), just to name a few.


You may have heard of curcumin, the powerful phytonutrient in turmeric. Curcumin has shown much promise for its anticancer effects through mechanisms that prevent cancer cell growth and promote cancer cell death. Include ground turmeric in stir fries, homemade veggie burgers, or take a curcumin supplement for additional support.


Myricetin is commonly found in plant-based food sources such as vegetables, tea, berries, nuts, and herbs. It has been studied due to its anti-carcinogen and chemopreventive affect in several cancers, including breast cancer. It was recently discovered that it may prevent metastasis (the process by which cancer cells spread to other parts of the body) of breast cancer cells.

What is chemoprevention?

Plant nutrients that have been shown to suppress cancer cell proliferation, inhibit growth factor signaling pathways, induce apoptosis (death of cancer cells), inhibit cancer cell activation pathways, and inhibit growth of new cancer cells, and, therefore, may have therapeutic value.


Geraniin is found in berries, pomegranates, walnuts. Geraniin has been shown to have antioxidant, antibacterial, anti-hyperglycemic, antiviral and anticancer properties. In regard to breast cancer, geraniin isolated from amla, a fruit native to south Asia, may prevent growth of breast cancer cells.


Tocotrienols are a class of fat-soluble antioxidants that are members of the vitamin E family and found in plant oils. Tocotrienols can act as antioxidants, improve blood flow, and support brain, heart and immune health. Studies have shown that they may encompass anti-tumor properties as they can inhibit the reproduction of cancer cells, including breast cancer. Foods with tocotrienols include cereal grains, rice bran, and barley.

Other notable phytonutrients that have shown protection against cancer include genistein (found in fava beans and soybeans), resveratrol (found in grapes, pistachios, dark chocolate), allicin (found in garlic), capsaicin (found in hot peppers), lycopene (found in tomatoes), ellagic acid (found in berries and walnuts), gingerol (found in ginger), silymarin (found in artichokes), and catechins (found in green tea and dark chocolate).


Additionally, research has studied the role of certain vitamins, specifically folate, vitamin D3, vitamin B6, and vitamin A, in relation to their effects on breast cancer chemoprevention and breast cancer recurrence.


Studies have shown that consumption of folate through whole foods (not supplements) may be associated with a decrease in the risk of developing hormone receptor-negative (HRneg) breast cancer, an aggressive subtype of breast cancer that accounts for 30–40 percent of all newly diagnosed breast malignancies. Increased folate intake in increments of 100 mg per day has been shown to correlate with a 10 percent decreased risk among women. Naturally occurring folate is found in leafy greens, oranges, strawberries, nuts, peas, and beans.

Vitamin D

Vitamin D has two primary forms, vitamin D2 and D3. Vitamin D2 (ergocalciferol) is derived from fortified and plant sourced foods, while vitamin D3 (cholecalciferol) is primarily derived from animal sourced foods, lichen (a combination of algae and fungus), and exposure to sunlight. Vitamin D3 has been shown to deliver two main benefits to breast cancer cells — suppressing cell growth and encouraging natural breast cancer cell death. More recent studies showed that vitamin D deficiency was directly related to breast cancer risk and the total amount of vitamin D in the blood had protective effects. Before supplementing with vitamin D, ask your healthcare provide to check your vitamin D levels to determine the amount you may need to supplement. Look for lichen-sourced vitamin D3 for plant-based origin D3 supplements. Getting 20-30 minutes of sunshine each day can help your body naturally produce vitamin D (bonus that it's also an instant mood-booster!).

Vitamin B6

Among postmenopausal women, adequate levels of pyridoxal 5′-phosphate (PLP), the active form of vitamin B6, were shown to be associated with a 20 percent reduction in breast cancer risk. Additionally, adequate intake of vitamin B6 through diet was significantly associated with 22 percent reduction in risk of all cancers. Plant-based sources of vitamin B6 include nutritional yeast, nuts, starchy vegetables, quinoa, oranges, tahini and sunflower seeds.