Should I switch my fussy baby to soy formula?

Ask Anne…

a crying babyQuestion: My 2 month old baby is fussy and spits up a lot. My doctor said she has milk allergies and recommended switching her to a soy formula. What do you think?

Answer: We know that cow’s milk is a very allergenic substance, because it  isn’t ‘species specific’. In other words, human milk is designed for human babies (who double their birth weight in  5-6 months), and not for baby cows (who double their birth weight in about 6 weeks).

Scientists have worked for decades to engineer a formula as close to breast milk as possible, by adding/removing substances found in cow’s milk, but in spite of all their efforts, many babies are still allergic to it. In fact, the top 6 allergens are: cow’s milk products (and formula is a ‘cow’s milk product’); soy; wheat, corn; eggs; and peanuts.

For this reason, the American Academy of Pediatrics recommends NO cow’s milk until your baby is at least a year old.

When you look at the list of allergens, you’ll notice that milk is closely followed by soy. That’s one of the reasons that intestinal upsets like colic aren’t ‘cured’ when you switch your baby to soy based formula. All soy formulas are modified to meet the minimum requirements for human milk substitutes, including added iron, vitamins, and minerals, as set by the AAP and the FDA, but hey don’t contain lactose, a milk sugar important to your baby’s health and development.

According to the American Academy of Pediatrics, “Soy protein-based formulas in the United States may account for nearly 20% to 25% of the formula market.”

If one in four babies are put on soy based formula, it’s obvious that mothers think that a soy formula is better for babies that cow’s milk formula. Many think that their baby’s fussiness or colic will be ‘fixed’ if their baby switches to soy, but this is not the case.

If soy formula doesn’t solve baby’s digestive problems, then why is soy formula recommended so often?

  • When babies have  galactosemia, a metabolic disorder that keeps them from breaking down the carbohydrate in milk and milk products, they may need a soy formula, because they can’t digest any dairy, including breast milk.  Galactosemia is a rare genetic disorder that occurs once in every 30,000-60,000 babies.
  •  When babies are truly lactose intolerant and can’t  fully digest lactose, the primary carbohydrate in cow’s milk, they may need a special formula. This is extremely uncommon, because the problem with cow’s milk is the protein, which is difficult for babies to digest, and not with the lactose. Human beings are not born lactose intolerant. Lactose intolerance is caused by a deficiency of the enzyme lactase, which breaks down lactose (milk sugar) so it can be easily digested. Mammals are born with this enzyme in their intestines. As they grow older and wean, the lactase enzyme decreases. That’s why lactose intolerance rarely shows up in humans  before age 3 or 4, since that’s around the natural age of weaning.
  • When babies are recovering  from an intestinal infection, some doctors recommend that babies be put on a soy formula.  However, The American Academy of Pediatrics does not recommend the routine use of soy formulas in infants recovering from diarrhea.
  • When baby’s parents are vegan and want their baby to have a plant based formula instead of one based on dairy.

What are the disadvantages of using soy based formula?

  • Soy contains substances similar to estrogen, and if babies ingest a lot of these ‘Phytoestrogens’, some research indicates that they might have a negative effect on children’s hormonal development during puberty. More research is needed on this topic, but it is a very real concern.
  • Soy has more protein, phosphorus and calcium than cow’s milk based formula, because these nutrients aren’t as well absorbed as formula based on dairy, so babies fed soy formula need more of them added.
  • Soy formula is often sweetened with corn syrup which may damage your baby’s teeth when used for long periods of time. It’s also made of corn, which is another top allergen.
  • Soy based formula may reduce the absorption of proteins and minerals, especially in premature babies
  • Soy formula doesn’t contain lactose, a sugar found in human milk, which is an important part of your baby’s diet. Lactose helps the baby’s intestine absorb iron and calcium, and promotes the growth of ‘friendly bacteria’ like lactobacillus, which help the baby develop his immune system and absorb nutrients, and create an acidic environment in which ‘bad’ bacteria can’t grow.
  • Lactose also contains a fat that helps the baby’s brain development. Human babies are meant to be fed human milk, and it doesn’t make sense that they would be allergic to a substance found naturally in breastmilk. Lactose is a sugar, not a protein. The protein in cow’s milk is what causes intestinal allergies like diarrhea and blood in the stools, because it’s a foreign protein from another species, and not meant for human babies.
  • Soy formula doesn’t help babies who are spitting up. Spitting up is less of a digestive problem than an anatomical one.
  • At least half of the babies who are allergic to cow’s milk are also allergic to soy because the proteins in both are very similar.
  • Dr. Sears says that  “Cow’s-milk-based formulas have been around for nearly a century. We don’t have that much experience with soy, so be cautious.”

If you have a fussy or colicky baby that spits up a lot or has other intestinal upsets, soy formula is probably not the answer. For formula fed babies who are truly allergic to dairy, a protein hydrolysate formulas like Alimentum or Nutramagen is probably a better choice than a soy based formula.

These formulas are predigested, which means the proteins in the milk are already broken down. They taste horrible and smell like cow’s milk spit up, and they are ridiculously expensive.

Cow’s milk is a highly allergic substance. The protein in from another species and wasn’t made for human babies, so it can cause an allergic reaction in the baby’s intestine that may show up as streaks of blood in the stool. Before you switch to a soy or a ‘hypoallergenic formula’, look at the possibility of your baby reacting to the foreign proteins in milk, and modifying your diet accordingly.

Remember that breastmilk is made for human babies, and there is no other food that is easier to digest than mama’s milk. When you consider switching to formula, remember all the live cells and immune factors in human milk that aren’t present in any formula, whether dairy based or plant based.

Always consult your doctor before making any change in your baby’s diet, including switching to formula.

Anne Smith, IBCLC
Breastfeeding Basics


About Anne Smith, IBCLC

Anne Smith, IBCLC
As the mother of six wonderful breastfed children, three perfect breastfed grand babies, and an IBCLC (International Board Certified Lactation Consultant) with over twenty-five years experience in lactation counseling, I can offer you professional support, as well as information and advice based on my personal experiences over the years.

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