December 2014 Issue

Update on Infant Formulas
By Judith C. Thalheimer, RD, LDN
Today's Dietitian
Vol. 26 No. 12 P. 32

Download table, "Recommended Uses of Common Infant Formulas," here

Over the years, manufacturers have introduced new, innovative varieties and categories. Learn what's available and how to help clients and patients choose what's best for their babies.

National and international health organizations all agree: Exclusive breast-feeding for at least one year is the best nutritional choice for infants.1 Still, somewhere around 75% of families in the United States will find that exclusive breast-feeding for one full year isn't an option.2 For these families, infant formula is a time-tested alternative.3

In all, the FDA estimates 1 million infants in the United States are fed formula from birth, and about 2.7 million will rely on formula for at least part of their nutrition by the time they're 3 months old.4 There are a wide variety of formulas on the market and choosing the right one can be confusing and stressful for families.

Why Formula?
Families must weigh medical necessity, practical considerations, and societal constraints when making the difficult decision of how to feed their baby. For babies who are adopted or have lost their mother, in many instances formula may be the only choice. While some medicines are safe when passed to a baby through breast milk, others are known to be harmful, and many have been inadequately studied, so mothers on medication may choose formula to reduce the possibility of risk to their infants.3 "Breast surgery is an often-overlooked impediment to breast-feeding," says James Kollmar, Jr, MD, a pediatrician with Horsham Pediatrics in Pennsylvania. Double mastectomies, of course, would rule out breast-feeding, and "While breast augmentation is usually fine, breast reduction surgery is often problematic," Kollmar says.

In the United States and Canada, more than one-half of all women with a child under 1 year old are part of the work force.5 The practical complications of returning to work certainly play a role in the use of infant formula. Families may choose formula for other reasons as well. Some feel it makes it easier for other caregivers to share in this intimate aspect of a baby's care. For others, lack of knowledge and support can lead to abandoning breast-feeding early on.3 "Perhaps husbands or grandmothers don't support them, or they don't know anyone who has breast-fed," says Bridget Swinney, MS, RD, LD, author of Eating Expectantly, Baby Bites, and Healthy Food for Healthy Kids, and president of the El Paso Academy of Nutrition and Dietetics. "So many moms quit breast-feeding when their babies go through a growth spurt and they think they can't make enough milk," Swinney says. In fact, the body responds to increased feeding demands by increasing milk production.6 While support from a lactation consultant or other expert can help to resolve many of these issues, the fact remains that the majority of breast-fed infants end up on a combination of formula and breast-feedings before their first birthday.3 "Families should understand that it's not 'all or nothing,'" Swinney says. "I'm of the philosophy that any breast milk is better than none. A combination of breast-feeding and formula feeding is often what works well when moms go back to work or school."

Formula Basics
Infant formula manufacturers try to mimic human milk.4 Like breast milk, formula is designed to deliver fluid for hydration; protein to provide amino acid building blocks for growth; carbohydrates to fuel the muscles, brain, and other organs; concentrated calories of fat for energy; and various vitamins and minerals.3 The three main categories of infant formula are differentiated by the type of protein they contain: cow's milk-based, soy protein-based, and hydrolyzed or amino acid formulas in which the proteins have been predigested.

Cow's milk-based formula is appropriate for the vast majority of infants. "Cow's milk-based formula is the most studied and, according to manufacturers, it is as close to breast milk as possible, so that's where we start if a mother is not able to breast-feed," says Sarah Krieger, MPH, RDN, a spokesperson for the Academy of Nutrition and Dietetics.

Soy-based formulas may be recommended for infants with known or suspected cow's milk protein intolerance or lactose intolerance. "Soy formula is appealing to vegan families," adds Krieger, "and is also used for those infants with galactosemia who aren't able to digest milk sugar." According to the American Academy of Pediatrics (AAP), soy formulas aren't recommended for low-birth-weight or preterm infants or for preventing colic or the development of allergies.3 There have been concerns about the effects of soy phytoestrogens on developing infants. However, these concerns appear to be unfounded. Recent research comparing children fed cow's milk protein formula vs soy protein formula as infants found no developmental differences.7

For the 2% to 3% of infants who have a true allergy to milk proteins, and for those with multiple allergies or intolerances, there are hypoallergenic extensively hydrolyzed formulas such as Nutramigen, Alimentum, and Pregestimil.3 Proteins in these formulas are already essentially predigested, broken down into small pieces that are safe for 90% of cow's-milk allergic babies. For those extremely sensitive infants who can't tolerate extensively hydrolyzed formulas, amino acid-based products such as Neocate or EleCare can be used.8 "These are the Cadillacs of infant formulas," Krieger says. "They can cost close to $40 or more per can. If a baby isn't tolerating milk-based formula well, I recommend families try soy formula first before switching to hydrolysate." Not all practitioners agree on this matter. "In our practice, we recommend iron-fortified milk-based formula. If there's a protein allergy, we move the baby right to an extensively hydrolyzed formula like Nutramigen or Alimentum, not to soy formula," Kollmar says. In the case of protein allergy or intolerance, health care professionals should work with the family to make a choice that meets the needs of the baby and the family as a whole.

Most milk-based infant formulas contain lactose as the major carbohydrate source. For infants who are lactose intolerant, Similac Sensitive, as well as many soy-based formulas, are made with alternative carbohydrate sources such as corn-syrup solids, sucrose, tapioca starch, modified cornstarch, and glucose polymers.3 Fat in infant formulas comes from vegetable oils including corn, soy, safflower, and coconut oils. Specialty products such as Enfamil Pregestimil are available with medium-chain triglycerides for infants with conditions affecting fat absorption.

Water is a key component in formula preparation. While liquid ready-to-use formulas don't require adding water, liquid concentrates and powders do. Adding too much water can lead to water intoxication, potentially resulting in low blood sodium levels, irritability, coma, and even permanent brain damage. Not adding enough water leads to diarrhea and dehydration, with the possibility of kidney failure, gangrene, and coma.3 "It's important to dilute as directed," Swinney says. "Parents should also be taught not to keep prepared formula more than 24 hours, not to save a bottle of formula for later if a baby hasn't finished it, and to follow good food-handling practices."

Research and Innovation
Over the years, formula manufacturers regularly have added or adjusted ingredients in response to emerging research or trends. In the United States, beginning in 1984, the amino acid taurine was added to infant formulas based on research showing that taurine-deficient infants had impaired fat absorption, bile acid secretion, retinal function, and hepatic function.1,9 In the early 2000s, the long-chain polyunsaturated fatty acids (LCPUFAs) DHA and arachidonic acid were added to many formulas;1 they're present in human milk and are important for development.

While research remains inconclusive, adding them to infant formula may help short-term cognitive function and vision.2,3 There has been a significant amount of research aimed at determining the ideal concentration and ratios of fatty acids for infant nutrition,3 and research continues to examine the impact of LCPUFA fortification on infant development. A 2013 meta-analysis in the journal Pediatrics that examined whether supplementation of infant formula with LCPUFAs improves visual acuity found mixed results.2

According to the FDA, vitamins and minerals are added to infant formulas at levels more than sufficient to ensure proper nutrition, and vitamin and mineral supplementation isn't necessary for healthy full-term infants taking formula.3,4 Iron was added to infant formula in 1959 to combat the common problem of iron deficiency.1,4 The infant formulas currently available in the United States are either "iron fortified" (approximately 12 mg of iron per liter) or "low iron" (approximately 2 mg of iron per liter).4 In 1999, the AAP declared low-iron infant formulas to be nutritionally deficient and strongly recommended against their use.3 "I don't believe in using low-iron formulas, because they don't have enough iron to support the developing infant brain," Kollmar says. "Some families think iron causes constipation or other problems in infants," he adds, "but they can rest assured it doesn't." Nonetheless, a 2012 study of infants in Chile found that iron-fortified formula had a negative impact on long-term developmental outcomes when fed to infants who weren't iron-deficient.10 More research is needed on this issue, but the AAP and FDA continue to strongly recommend against the use of low-iron formulas.4

Other components are added to various formulas in response to emerging research, parental concerns, or perceived needs. "Marketing goes along with the trends of research and what is acceptable to moms," Krieger says. "There are formulas with added rice starch for babies who spit up a lot, and one with added dietary fiber to help bulk up the stools of infants with diarrhea."

"There are so many things added now," Swinney says. "Prebiotics, probiotics, lutein for eye and brain development, and increased levels of vitamin E." And the variety of formulas goes beyond added ingredients. "There are different protein sources, different ratios of casein to whey, partially hydrolyzed protein, extensively hydrolyzed protein, or even elemental formulas. There are formulas with 19, 22, or 24 kcal per ounce instead of 20. There are even human milk fortifiers, used to increase the nutrient content of breast milk for preemies," Swinney says. "Formula to supplement breast-feeding is a pretty recent addition to the lineup," she adds. "While this can be seen as a marketing tactic, I like it because it might save a breast-feeding mom from quitting." In fact, a small randomized controlled trial published in 2013 in the journal Pediatrics found that early limited formula use may encourage long-term breast-feeding.11

Preterm and very low birth weight infants have extra nutritional needs to ensure proper growth and development. Special, nutrient-rich formulas have been developed for this population. On the other end of the spectrum are the formulas for toddlers. "Toddler formula is really not necessary," Kollmar says. "While cow's milk isn't safe for children under 1 year because it's iron-deficient, kids 1 year and older can get all the nutrients they need from solid foods and whole milk. Formulas marketed to different stages of development might keep people buying the products longer, but they aren't necessary for the health of the child."

Helping Families Choose
"Having more options isn't always better," Kollmar says. "The marketing competition going on out there is confusing the consumer."

Krieger agrees: "There's a huge variety of formulas on the market now. If I was a mom going down that aisle, I would be overwhelmed," she says. "I see families switching formulas up to four times in the first month of life looking for the perfect formula. Moms will tell me the baby is fussy and gassy and spits up all the time, and they're looking for a formula that will fix all that. We need to remind them that fussing and spitting up are just things babies do!"

Swinney says, "The truth is, a baby's digestive system is still developing, so some gas and fussiness is normal, and some may be caused by feeding techniques."

There are times when fussiness is a sign of something more. "If the baby is really fussy after every feed, or if they have eczema, excessive spit-up, or vomiting, they could have reflux or an allergy and they should see their doctor," Kollmar says.
Since there are so many formulas for specific issues, it's important for parents to consult with a health care professional when making decisions about what formula is best. "I think advertising drives a lot of formula decisions," Swinney says, "but RDs can help sift through the science and help parents decide what's best."

It's also important to stay informed on the latest products. "It seems that every year or so the formulas change names," Krieger cautions. "Often it's basically the same formula, but with a new name. Name changes confuse parents if this is not their first child."

All formulas on the market will provide the basic nutrition a healthy baby needs. For specific medical conditions, allergies, intolerances, prematurity, and very low birth weight, specialty formulas can be chosen with help from the baby's doctor. Fussing, crying, and spitting up are a normal part of infanthood, but if these behaviors seem excessive, especially if they're combined with other symptoms such as rash, congestion, or blood or mucus in the stool, the family should consult a doctor before switching formulas to identify the underlying cause of the problem.

"There's no doubt that breast milk is the gold standard for infant nutrition, but it's also a personal choice," Swinney says. "I've seen too many moms put through a guilt trip because they gave their babies formula. In some practice areas, formula isn't discussed at all—it's all about breast-feeding. This gives moms the impression that it's 'all or nothing' and can actually turn moms away from breast-feeding. No one likes to be guilted into doing something. As professionals, I think we need to lighten up a bit. A mom who's informed about breast-feeding and formula feeding can make the decision that best works for her. And if formula is the decision, we need to be ready to give them the information they need."

— Judith C. Thalheimer, RD, LDN, is a freelance nutrition writer, a community educator, and the principle of JTRD Nutrition Education Services.

1. Institute of Medicine (US) Committee on the Evaluation of the Addition of Ingredients New to Infant Formula. Infant Formula: Evaluating the Safety of New Ingredients. Washington, DC: National Academies Press (US); 2004.

2. Qawasmi A, Landeros-Weisenberger A, Bloch MH. Meta-analysis of LCPUFA supplementation of infant formula and visual acuity. Pediatrics. 2013;131(1):e262-e272.

3. Infant formulas. MedicineNet website. Updated January 17, 2014. Accessed October 1, 2014.

4. FDA takes final step on infant formula protections. U.S. Food and Drug Administration website. Updated October 10, 2014. Accessed October 12, 2014.

5. Marinelli KA, Moren K, Taylor JS; Academy of Breastfeeding Medicine. Breastfeeding support for mothers in workplace employment or educational settings: summary statement. Breastfeed Med. 2013;8(1):137-142.

6. Increasing milk supply. Ask Dr. Sears website. Accessed October 1, 2014.

7. Andres A, Cleves MA, Bellando JB, Pivik RT, Casey PH, Badger TM. Developmental status of 1-year-old infants fed breast milk, cow's milk formula, or soy formula. Pediatrics. 2012;129(6):1134-1140.

8. Formula options for infants with food allergies. Kids With Food Allergies website. Updated December 2013. Accessed October 2, 2014.

9. Chesney RW, Helms RA, Christensen M, Budreau AM, Han X, Sturman JA. The role of taurine in infant nutrition. Adv Exp Med Biol. 1998;442:463-476.

10. Lozoff B, Castillo M, Clark KM, Smith JB. Iron-fortified vs low-iron infant formula: developmental outcome at 10 years. Arch Pediatr Adolesc Med. 2012;166(3):208-215.

11. Flaherman VJ, Aby J, Burgos AE, Lee KA, Cabana MD, Newman TB. Effect of early limited formula on duration and exclusivity of breastfeeding in at-risk infants: an RCT. Pediatrics. 2013;131(6):1059-1065.