Soy-based formula has few advantages for babies, new medical guidelines say. The guidelines come from the American Academy of Pediatrics. Its members are doctors who specialize in caring for children. Breast milk is best, the report notes. But for those who use formula, the guidelines advise soy milk for only three groups of babies. These are babies who cannot tolerate the lactose in milk, come from strict vegan families, or have a rare condition called galactosemia. There's no proof that soy soothes fussy or colicky babies, the report says. And babies with a milk allergy should get hydrolyzed protein formula. That's because many of them also may be allergic to soy. The guidelines were released May 5. They were published in the journal Pediatrics.
What Is the Doctor's Reaction?
For nearly 100 years, soy formula has been right there on the shelves next to formulas based on cow's milk. About 20% of the formula sold in the United States is soy formula. Many parents, and some doctors, swear by it. They say it helps colic, is better for babies with diarrhea, prevents allergies and eczema, and is a good choice for babies who have milk allergy.
It turns out, though, that it doesn't actually help any of those things. Even worse, it possibly could be harmful.
This month, the American Academy of Pediatrics (AAP) published a report in its journal, Pediatrics, that lays out the facts. The report points out that:
Colic is rarely caused by what babies drink. While some babies may be calmed by the extra sugar and fiber in soy formula, studies have not shown that it helps colic significantly.
Infants with diarrhea don't get better any faster if you give them soy formula instead of breast milk or cow's milk formula. Giving soy formula may decrease the amount of loose stools slightly. However, lactose-free formula is widely available and works just as well.
There is no good evidence that giving soy formula prevents allergies and eczema.
Babies who have cow's milk allergy have a high risk of having a soy allergy as well. They should be given a hydrolyzed protein formula instead.
What makes this report even more important is that some research suggests that soy formula may actually cause health problems. It's certain that premature babies and babies born small shouldn't get soy formula, because it interferes with their bone growth.
Other concerns are far less certain. They relate to the high concentration of isoflavones in soy formula. Isoflavones are hormone-like substances that can have beneficial effects in adults. They may lower the risk of heart disease and certain cancers. But some studies have raised concerns about effects on the reproductive systems of infants.
Babies with thyroid problems who drink soy formula may need higher doses of thyroid medicine because of the hormone-like effects of soy.
The AAP is quite clear in its report that there is no conclusive evidence that soy formula interferes with reproductive or other hormonal systems in babies. However, there are many questions that need to be fully answered.
So why even have soy formula on the market? There are three groups of infants for whom soy formula makes sense:
Infants with galactosemia — In this rare disease, infants can't digest a sugar found in milk. They can have significant health problems without a special diet.
Infants who have hereditary lactase deficiency, also rare
Infants whose parents follow a strictly vegan diet
For everyone else, soy formula really doesn't make sense.
What Changes Can I Make Now?
If your baby is on soy formula and doesn't have galactosemia or hereditary lactase deficiency, and you aren't strict vegans, call your baby's doctor. Discuss changing to a formula based on cow's milk or a protein hydrolysate formula.
If your health care professional suggests that your baby change to soy formula, ask why. Remind them of the AAP report. They may not be aware of it.
If at all possible, breastfeed. There is abundant evidence that breast milk is best. The AAP recommends that babies be exclusively breastfed until they are 6 months old.
A recent report from the U.S. Centers for Disease Control and Prevention showed that the message is getting out: About 77% of new moms breastfeed, at least briefly. If you're pregnant, learn as much as you can about breastfeeding now. Be sure to set up a support network. Visit the website of the La Leche League to find breastfeeding support groups near you. Support will help make your breastfeeding experience much more successful.
What Can I Expect Looking to the Future?
Given that so many babies are currently on soy formula, it will be very important to do further research to understand the effects of isoflavones. We need to find out for sure if they can be harmful to babies.
I hope that we as a society will find more ways to educate parents about breastfeeding — and more ways to support moms as they breastfeed. If we can do this, fewer babies will need formula at all.
