Switch to sheep’s or goat’s milk “About 95 percent of sheep’s milk in the United States is produced from nonpregnant ewes,” says dairy expert David L. Thomas of the University of Wisconsin, Madison. As a result, sheep’s milk contains low amounts of pregnancy hormones. Goat’s milk also has a lower load ofhormones compared with cow’s milk.
Stick with skim or low fat In one study, skim milk had the lowest levels of a kind of estrogen that can stimulate breast-cancer tumor growth. In addition, skim and low-fat milk are considered healthier choices because of their low saturated-fat content. “Animal fat is linked to a higher risk of cancer in general,” says Moshe Shike, MD, director of clinical nutrition at Memorial Sloan-Kettering.
Consider lactose-free milk If you’re at high risk for ovarian cancer—you have a family history of the disease, or you have tested positive for the BRCA1 or BRCA2 gene—you could opt for widely available lactose-free milk at least part of the time. Goat’s milk is also a good alternative, since it has the least amount of lactose of all the dairy milks.
Go with rBST-free milk Recombinant bovine somatotropin (rBST) is a synthetic growth hormone that is now injected into about 17 percent of U.S. dairy cows to increase their milk production. Milk with rBST contains slightly higher levels of a protein that may be a marker for breast cancer in postmenopausal women; therefore, some experts advocate caution. Many stores (including Walmart) and food companies (such as Yoplait and Dannon) do not sell rBST dairy, and they use the label “rBST-free.” Or go organic: Laws prohibit using rBST in cows that produce that kind of milk.