Although women are actually more likely to develop heart disease, it’s breast cancer that strikes fear in their hearts. After lung cancer, it’s the most commonly diagnosed cancer in women, yet for most women, preventing it is a big mystery.
To some extent, your risk is already determined—by your age; your family medical history; when you got your first period and entered menopause; whether you had children or took birth control pills or hormone replacement therapy; and whether you carry one of the breast cancer genes, BRCA1 or BRCA2 (Only 5 to 10 percent of breast cancers are BRCA-related).
Even if the breast cancer odds aren’t in your favor, you can give yourself an edge. Monthly breast self-exams and annual mammograms are key, of course, to finding lumps that could be tumors. And the right diet can help prevent them. Scientists are still working to pinpoint which food guards against breast tumors, but we do know that eating more fruits, vegetables, whole grains, and lean protein while curbing saturated fat and trans fat covers you against a lot of diseases, including cancer.
This may be fruits and vegetables contain certain phytochemicals that have been singled out as effective cancer fighter. That’s important because the one thing we do know for sure about breast cancer is that gaining weight, especially later in life, substantially increase risk.
There’s much about breast cancer we can’t control, but what and how much we eat is something we can. Here’s where to start.
Broccoli and other cruciferous vegetables
If you’re going to eat more of just one vegetable, make it broccoli. Lab studies have found that a cancer-fighting compound in broccoli called sulforaphane stops breast cancer cells in their tracks and encourage them to self-destruct. Plus, another compound in broccoli, called indole-3-carbinol, appears to inhibit estrogen’s power to promote the growth of breast cancer cells. Broccoli’s anticancer powers have been shown in human studies, too. In one called the Western New York Diet Study, premenopausal women who ate the most broccoli had a 40 percent lower breast cancer risk than women who didn’t eat as much.
A bonus: Cruciferous vegetables like broccoli, cauliflower, and Brussels sprouts, which protect barbecue lovers from colon cancer, may also shield them from breast cancer. If you’re a big fan of cookouts, you’ll definitely want to steam some broccoli to go with those burgers and hot dogs.
Aim for four ½ cup servings a week of broccoli and other cruciferous veggies, which include cabbage, watercress, bok choy, turnip greens, mustard greens, and collard greens. If you are not a fan of straight broccoli, sneak it into other dishes. Try adding a half cup to pasta sauces, soups, pizza toppings, and even omelets. Steam, stir-fry, or microwave (in just a little bit of water) it instead of boiling it. These three cooking methods best conserve vegetables’ vitamins and protective compounds.
Beans, leafy green vegetables, and other foods rich in folate
Especially if you like to drink alcohol, even moderately, make sure you load your plate with plenty of these foods that supply folate, a B vitamin that alcohol depletes. It protects cells from the potential carcinogenic effects of alcohol.The foods listed above also contain plenty of fiber, which helps lower estrogen levels and in turn breast cancer risk. (Many breast cancer tumors feed on estrogen, so reducing it may prevent tumors from developing.)
Aim for at least one of the five vegetable servings recommended each day. Spinach is one of the richest sources of folate. If you won’t eat it alone, try layering it into lasagna or casseroles or sautéing it with olive oil, garlic, and sesame seeds to add other flavors.
Whole grains are another good source of fiber, and when it comes to preventing breast cancer, you really can’t get too much. Think of fiber as a type of flypaper, but instead of pesky insects, what you’re trapping is estrogen. Estrogen continually cycles through the digestive tract and is reabsorbed into the bloodstream. Fiber grams it so it won’t be reabsorbed, thereby lowering your body’s estrogen levels.
Whole grain foods may also help in other ways. Because fiber slows carbohydrate metabolism, foods like high-fiber cereals and whole-wheat bread may indirectly protect against breast cancer tumors by reducing blood sugar spikes, thereby keeping insulin levels low. Excess insulin is known to promote breast cancer growth.
In addition to their fiber, whole grains contain antioxidant phytochemicals called phenols, which can prevent and perhaps even repair damage to cells from dangerous molecules called free radicals. They also pack lignans, plant estrogens that lower natural estrogen levels in the body and actively slow the growth and spread of cancer cells.
Not all studies have demonstrated that fiber actively protects against breast cancer, but one in particular, the Canadian National Breast Cancer Screening Study, which examined nearly 57,000 women, found that those with fiber-rich diets had a 30 percent lower risk that those who ate smaller amounts.
Try to aim for at least three serving of whole grains daily. One serving is ½ cup of whole-grain pasta or rice or a slice of whole-grain bread. You can try mixing a cup of whole-grain cereal with ¼ cup of dried fruit for a tasty snack that covers you for a serving of whole grains and a serving of fruit.
You already know that fatty fish like salmon and tuna protect against heart disease, but could they protect against breast cancer, too? Some lab studies show that omega-3 fatty acids in these fish slow the growth of breast cancer cells. Studies in people have been less conclusive, but data from Singapore Chinese Health Study gives us some reason to be hopeful. That study looked at breast cancer incidence among more than 35,000 women and found that compared to women who did not eat much fatty fish, those who ate about three serving a week lowered their breast cancer risk by 26 percent. One reason may be the anti-inflammatory fats in these fish help reduce the low-grade inflammation that’s though to spur tumor growth.
Researchers are discovering that omega’3s seem to pack more punch when you eat fewer omega-6 fats like those in corn, safflower, and sunflower oils, which tend to promote inflammation. Women in the Singapore study whose diets were high in omega-6s and low omega-3s had an 87 percent greater risk of breast cancer than those whose diets were low in both types of fat.
Even if omega-3s don’t turn out to actively fight breast cancer, they are still good reasons to eat fish. If you have a salmon dinner in place of a steak dinner, you cutting back on saturated fat, which is a good idea if you’re worried about breast cancer.
It’s not clear how much fatty fish may protect against breast cancer. However, the American Heart Association recommends two servings (8 to 12 ounces total) of fatty fish each week to protect against heart disease.
Milk and dairy foods
That milk mustache you’ve seen in so many ads may help prevent against breast cancer—depending on your age. In the Nurse’s Health Study, which looked at more than 80,000 women, dairy foods seemed to have no effect for postmenopausal women, but premenopausal women who averaged two to three servings of low-fat or fat-free milk or dairy foods each day lowered their breast cancer risk by 28 to 32 percent compared to women who ate dairy just three times a month. Another study found that among more than 68,000 postmenopausal women, those who ate at least two servings of dairy foods a day lowered their breast cancer risk by 19 percent. Until we get more definitive data, eating low-fat dairy food is worthwhile.
Why dairy? It’s not entirely clear. The calcium may play a role, but researchers are also focusing on vitamin D. New research suggests that the type of vitamin D used to fortify milk (known as vitamin D3) reduces breast density, considered a risk factor for breast cancer.
Three servings of milk is the current recommendation. You may also want to take a vitamin D supplement, though. A cup of milk contains only about 100 IU of vitamin D3, and recent research suggest that 1,000 IU daily is associated with up to 35 percent lower risk of breast cancer. The Nurse’s Health Study found that premenopausal women who consumed more than 500 IU of vitamin D each day lowered their breast cancer risk by 289 percent.
The soy story
Does soy protect against breast cancer? That may depend on how old you are when you start eating it. Soy contains phytoestrogens, which are thought to lower the amount of estrogen circulating in your body and thus your breast cancer risk. But cancer specialists now believe that the reason Asian women have lower rates of breast cancer is that they grow up eating soy, unlike Western women who may start eating soy as adults.
The though is that soy’s phytochemicals may alter breast tissue as breasts are developing, making them more resistant to cancer-causing substances. Unfortunately, those phytochemicals may not protect women much once they reach adulthood.
That said, eating soy may still help, albeit indirectly. Eating tofu instead of, say, steak helps lower your calorie and saturated fat intake and maintain a healthy weight, all of which help reduce your overall risk of breast cancer. But there is one caveat: If you’re taking tamoxifen or another anti-estrogen medication, such as aromatase inhibitor that blocks estrogen, you shouldn’t eat soy.
Extra-virgin olive oil
It’s not just how much fat you eat but also what type of fat you eat that influences your breast cancer risk. While it’s generally though that eating too much fat increases risk, one can’t help but notice that that’s not always the case in Mediterranean countries, where fat intake is high but breast cancer incidence is low. The key, many researcher suspect, is that people in Mediterranean culture consume monounsaturated fat like that in olive oil rather than saturated fat like that in butter, ice cream, and meat or even polyunsaturated fat like that in corn or safflower oil. Indeed, a study of women in the Canary Islands showed that those who used at least 2 teaspoons of olive oil daily lowered their risk of breast cancer by an amazing 73 percent.
Research in this area is still unfolding, but a few theories have emerged. One is that olive oil is simply a healthier type of fat and that eating it in place of unhealthy saturated fat and trans fat lowers risk. The other piece of the puzzle is that olive oil comes from olives, fruits that contain many of the therapeutic compounds, like phenols and lignans, that we already know fight cancer. (Phenols inhibit the formation of cancer-causing compound. Lignans convert in the body to a weal estrogen-like compound that can displace the body’s own, stronger estrogen from cells.) Researchers at Northwestern University have also discovered that the oleic acid in olive oil actively suppresses a gene associated with the development of a very aggressive form of breast cancer and even improves the effectiveness of the cancer drug transluzumab (Herceptin).
The caveat, of course, is that olive oil is high in calories, so use it sparingly—instead of other fats, not with them. One reason olive oil may be so cancer protective is that it makes those veggies go down a little easier. Try sautéing vegetables in olive oil instead of butter or using olive oil in place of other vegetable oils in salad dressings.
These tiny seeds may turn out to offer big protection against breast cancer. Flaxseed (but not flaxseed oil) is even richer in lignans than olive oil and supplies alpha-linoleic acid, the plant form of omega-3 fatty acids, as well. Cell and animal studies as well as a preliminary study of 32 postmenopausal with breast cancer suggest that flaxseed helps reduce tumor growth and spread. Note: Research is still under way to determine how flaxseed may interact with anti-estrogen medications such as tamoxifen or aromatase inhibitors, so if you’re taking one of these breast cancer drugs, talk to your doctor before loading up on flaxseed. Also pregnant and breastfeeding women shouldn’t eat a lot of flax since there’s no safety data for them
Aim for a tablespoon of ground flaxseed daily. Buy it ground or grind it yourself in a coffee grinder, blender, or food processor. Store ground flaxseed in an airtight container in the fridge. You can add flaxseed to your meals by sprinkling it over cereal or salads, mixing it into yogurt or smoothies, or buying flaxseed-enriched products like breads and waffles.
Lose weight, lower your risk
There is one more thing that you can do that will surely help lower your risk of breast cancer: Maintain a healthy weight. Not only are heavy women more likely to develop breast cancer, they’re also more like to die from it. Data from the Nurse’s Health Study suggest that nonsmoking women who are overweight when they’re diagnosed are almost twice as likely as slender women to die of breast cancer.
More body fat equals higher estrogen levels. And excess body fat, particularly around the belly, produces proteins called cytokines, which increase inflammation and cause the kind of cell damage that can lead to cancer. For that reason, “apple-shaped” premenopausal women have more than double the breast cancer risk as the “pear-shaped” counterparts. Being overweight also goes hand in hand with higher levels of the tumor-stimulating hormones insulin and insulin growth factor-1.
During pregnancy, it’s important not to gain significantly more than the recommended 25 to 34 pounds and to lose that weight after giving birth. A Finnish study of more than 27,000 breast cancer patients found that gaining 40 pounds during pregnancy was associated with a 40 percent increase in breast cancer.
Gaining weight after menopause is also problematic. According to the Nurse’s Health study, women who put on 22 pounds after menopause raised their breast cancer risk by 18 percent.
So cut calories— and get off the couch. Even apart from weight loss, exercise appears to influence hormones in a way that’s protective against breast cancer as well.