Soy contains isoflavones that are similar to estrogen, which has been linked to breast cancer. However, isoflavones also protect against cancer. The American Cancer Society considers soy foods healthy food. Other health benefits for women who drink soy milk include heart health and bone health. Soy milk is also a nutritious alternative for women who have cow's milk allergies or lactose intolerance.
The controversy over soy milk and women involves the relationship between soy and breast cancer. According to the American Cancer Society, most studies that show an increased incidence of breast tumors and soy intake involve animals. Human studies haven't resulted in the same outcomes. In fact, some show a lower incidence of breast cancer when more soy is consumed. Because of these findings, the American Cancer Society concludes that consuming soy isn't harmful and may even lower your cancer risk. They do advise against taking soy supplements, however, because they contain higher levels of isoflavones than food.
According to the National Heart, Lung and Blood Institute, one in four women dies from heart disease. Eating a heart-healthy diet reduces your risk. Soy milk contains slightly more total fat than skim milk -- 5 grams versus 0.2 grams -- but, because it is plant based, contains no cholesterol. The fat in soy milk is unsaturated, making it a heart-healthy food. The American Heart Association recommends replacing higher fat animal foods with soy foods because they contain polyunsaturated fats, vitamins, minerals, fiber and low amounts of saturated fat. By switching from whole milk to soy milk you can reduce the amount of fat and cholesterol you consume, helping you maintain a healthy heart.
Soy milk and cow's milk contain similar amounts of calcium. As you age, your risk for osteoporosis increases. Consuming adequate amounts of calcium reduces your risk. A study in the 2011 journal, "Nutrition Research," found that, like women who drank cow's milk daily, women who consumed soy milk at least once a day had reduced incidence of osteoporosis.
Soy milk may be a healthy alternative for women with allergies to cow's milk or who are lactose intolerant. It contains a plant-based protein instead of an animal-based protein that may cause allergic reactions in some people. Soy milk is also lactose-free, so if you are lactose intolerant, you can drink soy milk without suffering from the intestinal issues you may experience when drinking cow's milk.
- American Cancer Society: The Bottom Line on Soy and Breast Cancer Risk
- Medline Plus: Heart Disease in Women
- USDA: National Nutrient Database for Standard Reference; Skim Milk
- USDA: National Nutrient Database for Standard Reference; Soy Milk
- Circulation: Soy Proteins, Isoflavones and Cardiovascular Health
- Nutrition Research: Soy Milk and Dairy Consumption is Independently Associated with Ultrasound Attenuation of the Heel Bone Among Postmenopausal Women: The Adventist Health Study–2