Yes, mammograms can discover cancerous breast cells early—but that’s not the first line of defense for women. “It’s time to think beyond detecting and treating breast cancer and put a greater emphasis on preventing it in the first place,” says Marisa Weiss, MD, founder of Breastcancer.org. And while a genetic predisposition to the disease is significant, the biggest known risk factor for postmenopausal breast cancer is being overweight. “Every 11 pounds you gain as an adult increases your risk by 3 to 5 percent,” notes Karen Collins, MS, RD, nutrition adviser to the American Institute for Cancer Research.
How to protect yourself, whatever your weight? First, exercise—the standard prescription of 30 minutes of aerobic activity a day helps fend off cancer even if you can’t drop pounds. Second, follow a healthy diet: eat lots of fruits, vegetables and grains, and monounsaturated and polyunsaturated fats (nutrients work better in combination than solo); minimize saturated fats; and give up trans fats. “Choosing the right foods can improve your odds of avoiding the disease and may help prevent a recurrence,” Weiss says. And this kind of meal plan should help you lose weight.
Here are some specific ingredients for your anticancer menu.
Powerhouse Preventive: Oleic Acid
Why you need it: You know about heart-healthy omega-3 fatty acids, but did you know you need omega-9s, too? According to a recent research review in the journal Clinical and Translational Oncology, an omega-9 called oleic acid helps kill cancer cells and enhances the effect of the breast-cancer drug Herceptin when taken by women with the disease.
Find it in: Almonds, avocados and olive oil. Extra-virgin olive oil is best because the first press produces the most phytochemicals, such as polyphenols, which may inhibit the growth of free radicals, notes Natalie Ledesma, RD, an oncology dietitian at the University of California, San Francisco.
How much you need: A small amount (one fifth of an avocado, 1 ounce of almonds, 1 tablespoon of olive oil) every day.
Bonus benefits: Preliminary research suggests that oleic acid, along with the monounsaturated fats found in the same foods, may help decrease belly fat, which would reduce your risk of insulin resistance and heart disease.
Powerhouse Preventive: Lignans
Why you need them: These phytochemicals, found in plant foods, may shift production of estrogen to less biologically active forms and reduce various cancer-related growths, which could explain why they are associated with a lower risk of breast cancer and possibly other types, Collins says.
Find them in: Beans, oats, barley and flaxseed. Flaxseed needs to be ground in order to release its lignans. Since it goes rancid quickly, buy ground flaxseed in small quantities and refrigerate it. Whole soy products, such as tofu and soy milk, also contain lignans.
How much you need: Some fruits and vegetables contain lignans, too, but eating three cups per week of oats, barley or beans is one approach to getting healthy lignans in your diet.
Bonus benefits: Lignans also act as antioxidants in the bloodstream, which could help prevent heart disease. Oats, barley and beans contain beta-glucan, a fiber that binds with cholesterol and whisks it out of your system.
Powerhouse Preventive: Flavonoids
Why you need them: These antioxidants not only have anti-inflammatory properties but also help protect you from cancer-causing agents. “Flavonoids repel free radicals, preventing them from getting through the cell wall and doing damage,” Ledesma says. That’s probably why preliminary research indicates that the lower a woman’s blood levels of flavonoids, the higher her risk of breast cancer.
Find them in: Green tea, wine (red has the most flavonoids, but white has some, too), grapes and chocolate.
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.
Powerhouse Preventive: Vitamin D
Why you need it: Women with the highest levels of vitamin D suffer from breast cancer 50 percent less often than those with the lowest, according to a meta-analysis done at the University of California, San Diego. A national survey found that 53 percent of American women are D deficient. Be sure you’re not one of them.
Find it in: Fatty fish (salmon, tuna, mackerel), eggs and fortified dairy products.
How much you need: The official suggestion is 200 IU a day, but the latest thinking calls for 800 IU. Since it’s hard to get enough D from food (a cup of fortified skim milk contains only 115 IU), you might need a supplement. But before you start popping pills, get a blood test to determine if your vitamin D blood levels are low (ask to be tested the next time you get your blood drawn), then consult with your doctor about proper dosage.
Bonus benefits: Some data suggest that people with high levels of vitamin D have lower rates of all cancers and a lower risk of premature death.
Originally published in the July/August 2010 issue of More.