10 Foods Linked to Lower Breast Cancer Risk: What Research Says About Fiber, Soy, Broccoli and Beans

No single food can prevent or cure breast cancer. But a growing body of research suggests that diet, particularly one rich in plant foods, may help lower the risk of developing the disease and support overall health for survivors.

Major cancer organizations recommend an overall eating pattern rather than any "superfood." According to the American Cancer Society, diets that focus on a variety of fruits and vegetables, whole grains, legumes, fish or poultry, and fewer red and processed meats are associated with lower breast cancer risk.

The American Institute for Cancer Research says eating mostly plant-based foods such as whole grains, vegetables, fruits and beans plays a big role in preventing cancer, because they are high in fiber, nutrients and natural substances called phytochemicals.

Here are 10 foods and food groups linked to lower risk in research.

1. Broccoli and other cruciferous vegetables

Broccoli, cauliflower, cabbage and kale are among the most studied. An analysis of two large cohorts found cruciferous vegetables were associated with lower risk of breast cancer, consistent with earlier findings of lower post-menopausal breast cancer risk.

2. Beans and lentils

Legumes are rich in fiber and protein. One study found high intake of bean fiber and fiber-rich foods such as beans and grains may lower the risk of ER-PR- breast cancer, an aggressive subtype for which few risk factors have been identified.

3. Whole grains

Oats, barley and brown rice add fiber. A meta-analysis of prospective studies found total fiber was associated with reduced risk of overall breast cancer.

4. Soy foods

Soy has been the subject of confusion, but evidence is reassuring. Soy products do not increase cancer risk, including the risk of breast cancer. Observational studies link moderate soy consumption, one to two servings a day, with lower breast cancer risk in Asia, where soy foods are commonly eaten throughout life.

Experts caution that the evidence is mixed. The AICR categorized evidence on soy and breast cancer risk as "Limited – No conclusion." Whole foods such as tofu and edamame are preferred over supplements.

5. Carrots, sweet potatoes and other carotenoid-rich vegetables

Non-starchy vegetables and carotenoid-rich vegetables may reduce the risk of estrogen receptor-negative breast cancer.

6. Fruits such as apples and citrus

One study found women who ate more than 5 1/2 servings of fruits and vegetables a day had a lower risk of breast cancer than those who ate 2 1/2 servings or fewer.

7. Olive oil

Researchers have linked polyphenols such as phenolic acids in olive oil to reduced breast cancer risk, and a Mediterranean diet naturally rich in polyphenols has been associated with lower incidence.

8. Tea

Flavonols in tea are among the polyphenols researchers have studied for possible protective effects.

9. Dairy and calcium-rich foods

Some evidence suggests that dairy products and calcium may reduce the risk of colorectal and breast cancer.

10. Fish and poultry in place of red meat

Swapping processed and red meats for leaner proteins fits the pattern linked to lower risk, according to the American Cancer Society.

What to limit

Alcohol is a notable risk factor. Alcohol may increase both pre- and postmenopausal breast cancer risk.

Guidance

The American Cancer Society recommends at least 2 1/2 to 3 cups of vegetables and 1 1/2 to 2 cups of fruit a day.

Most of this research is observational, meaning it shows associations rather than proof of cause. Diet is only one factor; genetics, age, weight and physical activity also matter. Anyone with concerns about breast cancer should talk with a doctor, and people undergoing treatment should consult their care team before changing their diet.

This article is for informational purposes only and is not medical advice.