If you’re a nutrition-savvy woman, you probably know to eat plenty of omega-3-rich coldwater fish to bolster heart health, or to make sure you’re getting ample fiber to ward off colon cancer and diabetes. But how often do you eat for breast health?

The truth is that what you eat and how much you get of certain nutrients can play a huge role in lessening the risk of cancer and other breast problems, say experts.

In fact, a third of the nearly 200,000 new breast cancer cases every year in the U.S. could be prevented by dietary changes, says cancer expert Leena Hilakivi-Clarke, professor of oncology at Georgetown University Medical Center in Washington, DC.

In addition to getting ample servings of fruits and vegetables and whole grains in breads and cereals, Hilakivi-Clarke and other experts recommend working these breast-smart food and supplement choices into your everyday habits.

Work in walnuts

Trade in your potato chips for a handful of walnuts. Walnuts contain healthy omega-3s, as well as antioxidants and phytosterols (another type of plant fat)—all of which have been shown to slow the growth of breast tumors. Earlier this year, a study presented at the American Association for Cancer Research showed that mice eating the human equivalent of 2 ounces (that’s just 14 walnuts) a day were much less likely to develop breast cancer, even though these rodents were at very high risk for the disease.

Related research shows that the same amount of walnuts in the diet can slow breast tumor growth by blocking cancer cell proliferation, which means that the breast tumors that did develop grew more slowly. Since walnuts pack a wallop of fat (even though it’s the healthy kind, it’s still fat) and concentrated calories, make sure you’re substituting walnuts for other snacks and not just eating them in addition to your normal intake, as weight gain raises the risk of breast cancer.

Trade coffee for tea

When researchers took a close look at the beverage choices of thousands of women, they found that women who regularly drank green tea lowered their risk of developing breast cancer by 12 percent. The more years and more often these women drank tea, the stronger was their protection from breast cancer.

Tea contains powerful antioxidants, with the superstar being one called epigallocatechin gallate (EGCG). Green and white teas, in particular, are packed with EGCG, although black and oolong teas also have some. EGCG deactivates harmful free radicals before they damage DNA and trigger cancerous changes.

But if you have breast pain or fibrocystic breast changes, you might consider avoiding methylxanthines, the family of caffeine and caffeine-like compounds in caffeinated coffee and tea (and in small amounts in chocolate). These can encourage painful breast cysts, says William Dunn, MD, from the West Michigan Cancer Center. If you’re quitting coffee and tea, be aware that it can take a few months for the pain to decrease or go away completely, notes Katherine Lee, MD, from Cleveland Clinic’s Breast Center.

Fill up on fiber

Keeping regular isn’t the only perk of a fiber-rich diet; fiber reduces the risk of breast cancer and keeps fibrocystic disease, mastalgia, and cysts at bay, says James Anderson, MD, a nutrition expert from the University of Kentucky.

Fiber’s role in breast-cancer risk reduction is still not completely understood, but the leading theory, says Anderson, is that fiber both “increases the excretion of estrogens and lowers estrogen levels in the blood.” Another reason fiber may work: It keeps waistlines trimmer. (Because fat tissue makes estrogen, being overweight ups the risk of breast cancer.)

Women should aim for 28 grams of fiber every day, men 38 grams. The average American gets just 15 grams. The fiber in cereals (think: oatmeal and whole-grain cereals) and fruits (particularly apples, figs, raisins) is particularly healthy for breasts.