Soy infant formula combines soy protein with vegetable oils and corn syrup to create a substitute for milk-based infant formula. Sometimes sucrose is also added for carbohydrate value. Soy-based formula has been on the market for more than 100 years and is generally given to infants who cannot tolerate the lactose in milk-based formula or in human milk. Also, families who are vegan—strict vegetarians who do not consume dairy products—may choose soy-based formula for ethical reasons. Milk-based formulas and soy-based formulas tend to give infants equal levels of nutrition because they typically come fortified with identical vitamins and minerals.
Occasionally parents give infants soy formula because of an allergy to proteins in cow milk formula. Unfortunately, making this switch rarely helps because many babies who are allergic to cow-milk protein are also allergic to soy protein. Hypoallergenic formulas composed of amino acids often work better as substitutes if a protein allergy is the concern. Additionally, lactose-free cow milk formulas are available for purchase.
The safety and side effects of soy infant formula frequently become subjects of debate due to the isoflavones found in soy products. Isoflavones are a type of estrogen normally found in legumes, with the highest concentration being in soybeans. Estrogen in plants is called phytoestrogen. Phytoestrogens have the ability to act like human estrogen in the body, which could potentially cause problems during the developmental stages of infancy. The fear is that the estrogen added to the body during infancy could lead to early-onset puberty in children. Infants get their nourishment solely from breast milk or formula, so the high level of soy exposure given to some babies can become a concern.
Most pediatricians consider soy infant formula safe for babies, but they suggest only using it if the child is lactose intolerant or in the situation where families are vegan. The American Academy of Pediatrics issued a statement in May of 2008 saying that although nearly a quarter of formula sales in America consist of soy-based purchases, there really are very few reasons to switch an infant to soy formula. Making a switch to soy infant formula generally does not help in controlling cases of fussiness or colic. The statement also makes it clear that there is no conclusive evidence showing that the phytoestrogen found in soy-based formula can harm infants.
Anti-soy activists worldwide have raised other concerns regarding soy infant formula. They speculate that its use can be linked to attention deficit disorder (ADHD), asthma and irritable bowel syndrome. None of these claims have been proven by a scientific study, and in the United States the FDA has concluded that soy formula is safe. Some other countries, such as Israel, require a prescription from a doctor to use soy infant formula. Any type of nourishment substitution for infants should be discussed beforehand with a family doctor.
