Soy milk is packed with essential nutrients and is a source of complete protein for vegetarian and vegan dieters. However, because soy contains compounds that are similar to estrogen, a female hormone, some people are hesitant to consume soy products. It appears that the pros of drinking soy milk outweigh any potential cons.
Nutrients in Soy Milk
Soy milk is rich in protein, and fortified with some of the same micronutrients found in cow's milk -- such as calcium, vitamin D, riboflavin, phosphorous, vitamin A, and vitamin B-12. One cup of soy milk generally provides about 8 grams of protein, the same amount found in a cup of low-fat cow's milk. The protein in soy milk is high quality protein, comparable to protein in animal foods, notes MedlinePlus. Soy milk is also a source of alpha-linolenic acid (ALA), which is an omega-3 fatty acid your body requires daily to function properly.
Cow's milk contains lactose, a natural sugar that some people have a difficult time digesting, but soy milk is lactose-free. Therefore, if you're lactose intolerant or have a milk allergy, soy milk is a nutritious substitute that shouldn't cause any negative side effects for you.
Possible Health Benefits
Soy milk may provide you with several health benefits. It's free from dietary cholesterol, saturated fat, and trans fat, which means it won't increase your risk for heart disease. In fact, the U.S. Food and Drug Administration says that consuming 25 grams of soy protein daily as part of a healthy diet may lower your risk for developing heart disease. MedlinePlus notes that isoflavones found in soy products may help prevent hormone-related cancers like endometrial cancer, prostate cancer, and breast cancer.
While numerous possible health benefits exist for drinking soy milk, some studies show potential concerns. A review published in 2014 in Alternative Therapies in Health and Medicine reports that some studies show soy might negatively impact fertility in men, while other studies show no effects. This review notes that some studies show soy increases thyroid hormone activity, while other studies found that soy decreases thyroid function. Lastly, milk protein appears to be more effective than soy protein at increasing lean muscle mass in athletes, according to a review published in 2012 in the Journal of the International Society of Sports Nutrition.
An experienced health, nutrition and fitness writer, Erin Coleman is a registered and licensed dietitian and holds a dietetics degree from the University of Wisconsin-Madison. She also has worked as a clinical dietitian and health educator in outpatient settings. Erin's work is published on popular health websites, such as TheNest.com and JillianMichaels.com.