Breast health: Your questions answered

Prevention

CAN DIETARY STEPS HELP PREVENT BREAST CANCER?
Cutting back on alcohol, red meat, and fat, especially trans fats, are three possible steps. Even a drink or two a day of beer, hard liquor, or wine might slightly increase the risk, possibly by affecting estrogen levels, and two to five daily drinks raises the risk 1.5 times that of teetotalers. Cutting total fat intake to about 15 percent of total calories might also slightly lower breast-cancer risk, especially among high-risk women, according to a study from the National Cancer Institute.

Reducing trans fat, which comes mainly from partially hydrogenated vegetable oil, might be particularly important. European researchers collected blood samples from nearly 20,000 women, then followed them for up to seven years. Women with a high level of trans fat in their blood had up to twice the risk of those with a low level. To limit your intake, check food labels, especially on processed foods, for the trans-fat content.

Consuming more than five servings of red meat a week might also boost risk, according to a recent study that followed more than 90,000 women for 12 years. Women who did were 42 percent more likely to develop the most common kind of breast cancer than women who ate fewer than three servings.

Certain other foods may help ward off breast cancer. Cruciferous vegetables such as broccoli and cabbage, for example, are high in indoles, compounds that may protect against breast cancer by lowering levels of estrogen, a hormone that fuels many tumors. But the best bet is simply a balanced diet high in a variety of produce, lots of whole grains, and moderate amounts of fish.

WHAT ABOUT SOY PRODUCTS?
The evidence is contradictory. Soybeans contain estrogen-like compounds called isoflavones that, in animal studies at least, fuel the growth of cancer cells and reverse the inhibitory effects that drugs such as tamoxifen (Nolvadex and generic) have on that growth. Yet Asian women, who tend to consume lots of soy foods, have a lower incidence of breast cancer than do women in Western countries. On balance, it's probably safe for most women to consume soy products as long as they don't go overboard (no more than about 100 mg of isoflavones a day). But women who already have breast cancer or are at high risk for it should limit their consumption.

CAN CERTAIN MEDICATIONS PREVENT BREAST CANCER?
Yes, but the risks make it worthwhile only for very high-risk women. Researchers have long known that tamoxifen can cut the risk of breast cancer in half. And a manufacturer-funded study published in June found that the related drug raloxifene (Evista) is nearly as effective. Other research suggests it is slightly less likely to cause cataracts.

But rates of heart attacks and strokes remain unacceptably high for most people. Research suggests that the risk-benefit ratio is favorable for women younger than 50 whose five-year risk of breast cancer is at least 2.5 percent. In older women, the ratio generally favors only white women in their 50s with a five-year risk of at least 4.5 percent. One way to determine your five-year risk is with the National Cancer Institute's risk calculator, and discussing the results with your physician. But don't feel pressured into taking a drug. Everyone's tolerance for risk differs, so there's no right or wrong approach, even if the calculator indicates a possible benefit for you.