They gave cow's milk formula a try, even though they'd both had trouble with it themselves as children. As it turned out, their suspicions were right: Emily promptly came down with diarrhea. So they switched to a soy formula, and Emily did fine.
For these parents and some others, choosing between formula types is a "no-brainer" since it's based on the comfort and symptoms of their child. But for parents whose babies can tolerate either type, the decision isn't so simple.
The American Academy of Pediatrics (AAP) recommends that parents give soy formula only to infants who cannot digest cow's milk or to those whose parents wish them to follow a vegan diet. For the majority of infants, the AAP says cow's milk formula is still the next best thing to breast milk. Yet the popularity of soy formulas among U.S. parents has increased, with 1 in 4 now opting for soy, according to the academy's estimates.
With growing attention to the possible health benefits of soy products, parents may be choosing this type of formula thinking it's healthier for their babies. But the AAP says it may not be so. And while the academy doesn't claim that soy formula will lead to the development of health problems, some experts aren't so sure.
The estrogen connection
The main concern about soy formula is that it contains high levels of phytoestrogens -- estrogen-like substances found in some plants. People who are worried about soy formula fear that these substances could interfere with a child's development and even cause early puberty, thyroid problems, breast development in male children, or other difficulties. Because of these concerns, a consumer group in New Zealand tried to have soy formula removed from the market in the mid-1990s. That didn't happen, but the New Zealand Ministry of Health did issue an advisory opinion to parents in 1998 recommending cow's milk formula over soy.
The next year, the concern crossed the globe when the Canadian Health Coalition, a group of consumers and health care professionals, called on the Canadian government to restrict the use of soy formulas there. So far the restriction hasn't come to pass, but the debate continues. Today, about one in five Canadian infants uses soy formula, according to estimates from the Infant Feeding Action Coalition in Canada.