What Proteins are Used in Baby Formulas and Why are They Used?

With so many different baby formulas on the market, parents often wonder what makes them so different from each other and how to choose what formula is best for their child. One component that can make one formula different from another is the formula’s protein source. Certain sources of proteins can be harder to digest, and some can even cause allergic reactions for some children, so getting the right-for-you protein ingredient in your baby’s formula is important.

This article explains what kind of protein is used in baby formula and why.

Why is protein important for babies?

Proteins are the building blocks for all tissues in the body. They are extremely important for how the body works because proteins are used to make hormones, enzymes, and other substances to support growth and development. Sources of protein can either be animal-based or plant-based.

What kind of protein is used in baby formulas?

There are many sources of protein used in baby formulas. Animal-based (dairy-based) sources of protein used in baby formulas include cow’s milk, goat’s milk, whey protein, organic milk protein concentrate, milk protein isolate, and casein hydrolysate. Plant-based sources of protein used in baby formulas include soy protein, pea protein, and even almond butter.

Why do many baby formulas include nonfat cow’s milk as the protein source?

Nonfat cow’s milk has been the  “go to” substitute to include in baby formula when breast milk is not available. It contains essential amino acids (building blocks of proteins) that little ones need. It also excludes fat, which can be hard for infants to digest. ¹ When nonfat milk is used, it's accompanied by an appropriate blend of oils to ensure that a full complement of good fats is available. Standard nonfat cow’s milk is used in the manufacturing of both organic and non-organic formulas, including Baby’s Only® Organic Dairy Toddler Formula, Baby’s Only® Organic Dairy DHA/ARA Toddler Formula, Baby’s Only® Organic Gentle Toddler Formula, Baby’s Only® Organic Gentle DHA/ARA Toddler Formula, and Baby’s Only® Organic Premium Infant Formula.

Learn more about Baby’s Only® Organic Premium Infant Formula here.

Why is whey protein added to baby formula?

Whey protein is often added to a baby formula made with nonfat milk to bring the ratio of two proteins, whey and casein, closer to the ratio that is found in mature human milk.

The two primary proteins in milks are whey and casein. If you remember the nursery rhyme about Little Miss Muffet eating her curds and whey, she was probably eating cottage cheese! You can picture the small curds in cottage cheese as casein and the watery portion as whey.

Whey and casein are present in both human milk and in cow’s milk. Mature human milk is approximately 60% whey and 40% casein,whereas cow’s milk is approximately 18% whey and 82% casein. ² To resemble human milk more closely, a combination of nonfat cow’s milk with added whey protein is used in many formulas. Whey protein is used in the manufacturing of both organic and non-organic formulas. You’ll find organic whey protein in Baby’s Only® Organic Gentle Toddler Formula, Baby’s Only® Gentle DHA/ARA Toddler Formula, and Baby’s Only® Organic Premium Infant Formula. Formulas with added whey protein may aid in digestion and help produce softer stools.^3-5

Why are organic milk protein concentrate and milk protein isolate included in some baby formulas?

Organic milk protein concentrate (used in organic formulas) and milk protein isolate (used in non-organic formulas) are sources of protein included in baby formulas since they contribute a source of protein with little to no lactose, which is important for babies with lactose sensitivity or lactose intolerance. Organic milk protein concentrate is used in Baby’s Only® Organic Sensitive DHA/ARA Toddler Formula.

Why is goat’s milk used in some baby formulas?

There is a growing interest in the use of alternative milks, like goat’s milk, within baby formula. Some research indicates that the proteins in goat milk may be easier digested than cow’s milk. ^6-11 Goat’s milk protein offers more A2 beta casein, less alpha-s1 casein, and a form of Beta-lactoglobulin less resistant to digestion, and these aspects appear to contribute to making goat milk more efficiently and quickly digested.^7-11 Baby’s Only® Goat Milk Toddler Formula with DHA and ARA provides parents with another option for feeding their child that they can feel good about!

What does “hydrolyzed” mean and why are hydrolyzed proteins included in some baby formulas?

You can think of “Hydrolyzed” like “broken down.” A “hydrolyzed” protein has gone through a “hydrolysis” process to break the protein into amino acids (the building blocks of proteins) and small peptides (2 or more amino acids linked together). A “hydrolysate” is what results after hydrolysis.

When the casein portion of cow’s milk is broken down into amino acids (the building blocks of proteins) and small peptides (2 or more amino acids linked together), this ingredient is called “casein hydrolysate.” Studies suggest that formulas made with extensively hydrolyzed proteins such as casein hydrolysate can reduce allergic responses to the proteins in cow’s milk. Because of this, extensively hydrolyzed formulas are often recommended when children are diagnosed with cow’s milk protein allergies.

Some formula companies also sell partially hydrolyzed formulas, which are made with partially hydrolyzed whey protein. These formulas often claim “easier digestion” because some of the cow’s milk protein has been hydrolyzed or broken down.

At this time, extensively hydrolyzed proteins do not meet organic standards and there are no organic certified extensively hydrolyzed protein formulas on the market.

Why do some baby formulas include plant-based proteins?

There is a growing interest in plant-based formulas largely due to the growing interest in our planet’s sustainability, with many families choosing a more vegetarian or plant-based lifestyle. Traditionally, the only plant-based formula option available for families was a soy protein formula. Now, other options like plant-based pea protein formulas are available!

What is organic pea protein concentrate and why is it used as an ingredient in toddler formulas?

Organic pea protein concentrate is a dairy-free and soy-free source of protein. Baby’s Only® Organic Plant Based Pea Protein Toddler Formula was the first, and is currently the only, plant-based pea protein toddler formula. Baby’s Only® Organic Plant Based Pea Protein Toddler Formula uses organic pea protein concentrate as its protein source. To make organic pea protein concentrate, organic yellow peas are ground into a powder. Then, with water – and no harsh chemicals or solvents – the fiber and the starch components of the powder are removed, resulting in pea protein concentrate.

Baby’s Only® Organic Plant Based Pea Protein Toddler Formula can be used as a formula for those who prefer a vegetarian or plant-based lifestyle, for lactose intolerance, for galactosemia, or for those who seek a dairy-free and soy protein free formula.

Peas are legumes just like soybeans, peanuts, and many dried beans. While soy protein is an allergen, pea protein is not a major allergen like soy and mashed peas are often fed as one of the first foods offered to a child. Because a pea protein allergy is rare, it can be a possible alternative option for a child with cow’s milk protein allergies and intolerances under the direction of their healthcare provider.

Why is soy protein included in some baby formulas?

Soy protein, often in the form of soy protein isolate, is a source of protein included in soy-based baby formulas.

Soy formulas have been used for children with a cow’s milk protein intolerance, but they are not often appropriate for a child with a diagnosed cow’s milk protein allergy. The reason is that many children with cow’s milk protein allergy may also be allergic to soy protein. Other reasons for the use of a soy formula are lactose intolerance (since lactose is not used as a carbohydrate source), the preference for a plant-based formula, and the genetic condition known as galactosemia.

Why is almond butter used in baby formula?

Almond butter is now used in some toddler formulas. Like peanut butter, almond butter is a major allergen. There are still questions regarding its use for feeding infants or as a sole source of nutrition. Questions exist on whether an almond butter-based formula provides complete protein needs. The verdict is still out on whether this is in fact a nutritious and safe option for infants and young children.

What source of protein in formula is best for my baby?

Your child’s healthcare provider can help you determine the source of protein that is best for your baby. Generally, many healthcare providers will recommend an infant begin with a“standard” formula, which is usually made with nonfat milk and whey protein, such as Baby’s Only® Organic Premium Infant Formula, where the protein ingredients are organic. If a child experiences reflux, gas, constipation, allergies, intolerances, or colic, a child’s healthcare provider may recommend formulas with other sources of protein like some of the other protein ingredients mentioned within this article.

As with any decision regarding what type of formula to use with your little one, always check with your child’s healthcare provider for advice.

References:

1. Petit V, Sandoz L, Garcia-Rodenas CL. Importance of the regiospecific distribution of long-chain saturated fatty acids on gut comfort, fat, and calcium absorption in infants. PLEFA. 2017. 121:40-51.
2. Kunz C, Lönnerdal B. Re-evaluation of the whey protein/casein ratio of human milk. Acta Paediatr. 1992;81(2):107-112. doi:10.1111/j.1651-2227.1992.tb12184.x
3. Malacaman EE, Abbousy FK, Crooke D, Nauyok G. Effects of protein source and iron content of infant formula on stool characteristics. Journal of Pediatric Gastroenterology and Nutrition. 1985; 4:771-773.
4. Rochat F, Cherbut C, Barclay D, et al. A whey-predominant formula induces fecal microbiota similar to that found in breast-fed infants. Nutrition Research. 2007; 27:735-740.
5. Balmer SE, Scott PH, Wharton BA. Diet and faecal flora in the newborn: casein and whey proteins. Archives of Disease in Childhood. 1990; 64:1678-1684.
6. Sae-In S Kay, Stefanie Delgado, Jeenu Mittal, Rebecca S Eshraghi, Rahul Mittal, Adrien A Eshraghi, Beneficial Effects of Milk Having A2 β-Casein Protein: Myth or Reality?, The Journal of Nutrition, Volume 151, Issue 5, May 2021, Pages 1061–1072, https://doi.org/10.1093/jn/nxaa454
7. Jung TH, Hwang JH, Yun SS et al. Hypoallergenic and Physiochemical Properties of the A2 B-Casein Fraction of Goat Milk. Korean J. Food Sci. An. 2017;37(6):940-947. DOI: 10.5851/kosfa.2017.37.6.940.
8. Ye A, Cui J, Carpenter E, et al. Dynamic in vitro gastric digestion of infant formulae made with goat milk and cow milk: Influence of protein composition. Int Dairy J. 2019. 97:76-85.
9. Almaas H, Cases AL, Devold TG, et al. In vitro digestion of bovine and caprine milk by human gastric and duodenal enzymes. International Dairy Journal. 2006. 16:961-968.
10. Hodgkinson AJ, Wallace OAM, Boggs I, et al. Gastric digestion of cow and goat milk: Impact of infant and young child in vitro digestion conditions. Food Chemistry. 2018. 245: 275-281.
11. Prosser CG. Compositional and functional characteristics of goat milk and relevance as a base for infant formula. JFDS. 2021. 86(2):257-265. doi:10.1111/1750-3841.15574