How much you need: Have one serving of some sort of flavonoid each day—an ounce of chocolate or a glass of purple grape juice. But if you choose wine, don’t go overboard. “One drink is OK; more is not,” says Cynthia Thomson, PhD, RD, associate professor of nutritional sciences at the Arizona Cancer Center in Tucson. A study reported last year in the Journal of the National Cancer Institute found that for women each additional daily drink significantly increased the risk of breast cancer and other cancers. Limit yourself to 5 ounces of wine daily; use a measuring cup until you can pour accurately.
Bonus benefits: Flavonoids boost heart health, making arteries more flexible and reducing plaque formation.
Powerhouse Preventive: Vitamin A
Why you need it: A 2008 study that compared newly diagnosed breast-cancer patients with healthy women concluded that running short on this vitamin doubles the risk of developing breast cancer. The theory: Vitamin A (along with other antioxidants) can help stem the damage caused by free radicals in the body.
Find it in: Very dark green vegetables like broccoli, spinach and bok choy and deep-orange fruits or vegetables like carrots, sweet potatoes, winter squash, cantaloupes and mangoes. Despite their color, oranges don’t belong in this group.
How much you need: Collins recommends 700 to 900 mcg a day for women. You’ll get this amount if you eat a half cup each day of one of the aforementioned foods, Collins notes. (If the spinach is raw, up your serving to three quarters of a cup.) Since this fat-soluble vitamin is stored in the liver, it’s possible to get a toxic overdose over time, so nutritionists recommend getting your A from food rather than pills.
Bonus benefits: Vitamin A is crucial for maintaining your immune system.
Powerhouse Preventive: Folate
Why you need it: This B vitamin helps keep DNA healthy and is needed for cell growth. A large Swedish study published in the American Journal of Clinical Nutrition found that women with the highest folate levels had a 44 percent lower risk of breast cancer than those with the lowest. Folate is particularly protective in women who drink alcohol. But while it’s impossible to overdose on the folate found naturally in foods, getting too much of its cousin, folic acid—the form of folate that’s added to multivitamins and fortified foods—can actually cause cancer cells to grow, Collins says. Check labels and aim for 400 mcg a day; levels over 1,000 mcg are considered dangerous.
Find it in: Dark green leafy vegetables, beans, peas, lentils and citrus fruits.
How much you need: One to two servings daily.
Bonus benefits: Folate plays a key role in the formation of red blood cells.
Powerhouse Preventive: Lycopene
Why you need it: It has been shown to inhibit the growth of breast-cancer cells, Ledesma says.
Find it in: Watermelons, apricots, guavas, papayas and tomatoes. Cooked and canned tomatoes and tomato sauce contain even more lycopene than the fresh ones do. Why? Heating breaks down the cell wall of the tomato, allowing the micronutrient to be better absorbed by the body’s cells. To make this fat-soluble pigment more available to your body, drizzle tomatoes with olive oil.
How much you need: Aim for at least two servings each week.
Bonus benefits: Lycopene helps prevent lung and stomach cancer as well.
Powerhouse Preventive: Sulforaphane
Why you need it: This compound inhibits the growth and spread of human breast-cancer cells, according to research by Nancy E. Davidson, MD, director of the University of Pittsburgh Cancer Institute.
Find it in: Brussels sprouts, cabbage, cauliflower, broccoli (especially the sprouts), kale and other veggies that contain sulfur compounds, which give off a telltale odor when cooked.
How much you need: “Try to eat one of these veggies every day,” Weiss advises.
Bonus benefits: Sulforaphane is also critical in fighting other cancers, especially lung and prostate.