Soy milk is a plant-based alternative to cow's milk that many people choose for health reasons. Soy milk contains phytoestrogens, a plant-based form of estrogen that mimics the effect of the hormone estrogen. Estrogen is primarily a female hormone, even though both males and females produce estrogen. The fact that soy milk contains estrogens makes some people worry whether soy milk is safe for boys to drink.
The primary concern surrounding soy milk and boys is the fear that the phytoestrogens in the soy will interfere with male hormones, leading to delayed or weakened sexual development that can compromise fertility. Soy milk can interact with a boy's natural estrogen levels, according to Dr. Walter C. Willett of the Harvard School of Public Health, but there is no evidence that fertility is impaired. Dr. Willett believes that soy milk is safe for both boys and girls to drink in moderation.
Boys and men who drink soy milk may enjoy some future health benefits, including a reduced risk of breast cancer -- already a rare occurrence in males -- and prostate cancer. The Physicians Committee for Responsible Medicine's Cancer Project explains that the same phytoestrogens that some people fear will adversely effect a boy's hormones can actually lead to a lower incidence of prostate cancer and a longer survival rate.
Nutritionally speaking, soy milk provides many of the same nutrients as cow's milk, but in different doses. Soy milk contains fat, protein and calcium just as cow's milk does, and also fiber and iron, which cow's milk does not contain. Even though soy milk can be a nutritious beverage for a boy, the differing nutritional values may not be appropriate for a growing toddler who needs substantial calories and fat for normal development. Eight ounces of soy milk contains 100 calories versus 146 in whole milk, and less fat than either whole or 2 percent milk.
Soy-based formula can be a safe and appropriate alternative to milk-based formula or breast milk for infants who suffer from lactose intolerance or other digestive difficulties. Check with your doctor before switching your baby boy to soy-based formula.