When it comes to feeding a newborn baby, breastmilk is widely considered the gold standard. Breastmilk provides complete nutrition for babies in the first 6 months of life, containing the ideal balance of fat, protein, carbohydrates, vitamins, and minerals. Breastmilk also contains important bioactive components like antibodies, enzymes, hormones, and prebiotics that support immune function, digestion, and development.
However, breastfeeding may not be possible or preferable for all mothers. In cases where breastmilk is not available, formula can provide a healthy alternative for infant feeding. But with so many formula options on the market, how do you know which is the closest match to breastmilk? Here we review the key components of breastmilk and compare different formula types to determine which formula comes closest to the nutritional profile of breastmilk.
Key Components of Breastmilk
Breastmilk contains hundreds of distinct components that work synergistically to meet a baby’s nutritional needs. Here are some of the most important components that make breastmilk unique:
Macronutrients:
- Carbohydrates – Lactose is the primary carb in breastmilk, providing energy.
- Protein – Whey and casein proteins provide amino acids for growth and development.
- Fat – Breastmilk contains hundreds of fatty acids like DHA and ARA for brain growth.
Micronutrients:
- Vitamins – Especially vitamin A, C, D, E, and B vitamins.
- Minerals – Like calcium, phosphorus, zinc, iron, and magnesium.
Bioactive Components:
- Enzymes – Like lipase to assist with fat digestion.
- Hormones – Including insulin, leptin, and adiponectin.
- Oligosaccharides – Prebiotics that feed healthy gut bacteria.
- Immunoglobulins – Antibodies that provide passive immunity.
- Lysozyme – An antimicrobial enzyme that fights infection.
- Growth Factors – Support tissue growth and maturation.
- Nucleotides – Building blocks for DNA and RNA.
This complex nutritional profile changes over time to meet a baby’s needs. Colostrum produced in the first few days after birth is higher in immunoglobulins. As lactation progresses, breastmilk adapts its macronutrient content based on the age and size of the infant. No formula can fully replicate all the components in breastmilk, but some come closer than others.
Standard Cow’s Milk Formula
For decades, standard cow’s milk-based formula was the norm for bottle feeding infants. However, research has shown that the nutritional profile of standard cow’s milk formula differs significantly from breastmilk in a few key ways:
- Higher in casein protein than whey protein.
- Lower in essential fatty acids like DHA and ARA.
- Contains different profile of oligosaccharides.
- Much higher renal solute load.
- Potentially harder to digest.
Due to these compositional differences, some babies fed standard cow’s milk formula are at higher risk of gastrointestinal issues, kidney stress, and nutrient deficiencies. While formula companies have made some improvements by partially hydrolyzing proteins, adding DHA/ARA, and supplementing with prebiotics, standard cow’s milk formula remains nutritionally inferior to breastmilk.
Partially Hydrolyzed Formula
Partially hydrolyzed formulas take cow’s milk proteins and break them down into smaller peptides through enzymatic processing. This makes the proteins easier to digest. Partially hydrolyzed formulas like Enfamil Gentlease are sometimes used for babies with minor feeding tolerance issues such as mild colic, gas, or reflux.
However, partially hydrolyzed formulas still have an imbalance of whey and casein compared to breastmilk. And they lack some bioactive components found in breastmilk. Partially hydrolyzed formulas are an improvement over standard cow’s milk in terms of digestibility. But they are not nutritionally equivalent replacements for breastmilk.
Extensively Hydrolyzed Formula
Extensively hydrolyzed formulas use more advanced enzymatic processing to break down the proteins into amino acids and very small peptides. Examples include Alimentum and Nutramigen. They are designed for babies with more significant gastrointestinal issues like severe cow’s milk protein allergy or colic.
The more extensive protein breakdown makes these formulas highly digestible and hypoallergenic. However, the process also destroys some bioactive components in milk that are beneficial. And they still do not mimic the balanced macronutrient or micronutrient profile of breastmilk. So while helpful for therapeutic uses, extensively hydrolyzed formulas are not good nutritional stand-ins for breastmilk for routine feeding of healthy infants.
Amino Acid-Based Formula
The most hypoallergenic infant formulas are those made from individual amino acids. Neocate and Elecare are examples. These are useful for severe food allergies and GI conditions requiring an elemental diet.
However, amino acid formulas have minimal bioactive components and altered nutritional composition compared to breastmilk. The protein, fat, carbohydrate, and micronutrient balance does not mimic breastmilk. So while beneficial for therapeutic intervention, amino acid formulas are not equivalent substitutes nutritionally.
Organic Formula
Organic formula uses organic cow’s milk, but is still fundamentally cow’s milk in composition. While the organic methods minimize pesticide exposure, the actual nutritional content is not significantly different from standard formula. Organic formula does not have compositional improvements that bring it closer to breastmilk.
Goat Milk Formula
Goat milk formula swaps out cow’s milk proteins for goat milk proteins. However, the overall macronutrient and micronutrient profile remains cow milk-like rather than human milk-like. There is limited evidence that infants find it easier to digest compared to standard cow’s milk formula. But there is no evidence that it better mimics the diverse components of breastmilk compositionally.
Soy Formula
Soy formula is made from soy protein isolates and oils rather than cow’s milk. It does not contain lactose, which may help with lactose intolerance. However, soy formula differs compositionally from breastmilk in many other ways:
- Higher in phytoestrogens
- Lower in whey protein
- Missing milk fat globule membrane
- Contains phytates that impair mineral absorption
Due to breastmilk being nutritionally superior, the American Academy of Pediatrics recommends soy formula be used only for infants with cultural/dietary preferences or cow’s milk protein allergy. Otherwise, soy formula is not recommended as an equivalent stand-in for breastmilk.
Human Milk Oligosaccharides (HMOs) in Formula
Human milk oligosaccharides (HMOs) are a group of complex carbohydrates naturally found in high concentrations in breastmilk. Over 150 different HMOs have been identified, making them the third most abundant solid component in breastmilk after lactose and fat.
HMOs act as prebiotics to support the growth of healthy gut bacteria. They also help prevent pathogen binding and directly modulate immune function. Infant formula does not naturally contain HMOs. However, some newer formulas are now supplemented with HMOs to try to provide specific benefits of breastmilk:
- Similac Pro with 2’FL HMO
- Enfamil NeuroPro with 2’FL HMO
- Gerber Good Start with 2’FL HMO
While HMO supplementation brings formulas a step closer to breastmilk, these formulas still only contain one or two of the most abundant HMOs. They lack the full spectrum of diverse HMOs present in breastmilk that work synergistically. So HMO supplementation alone does not make formula equivalent to breastmilk compositionally.
Milk Fat Globule Membrane (MFGM) in Formula
In breastmilk, fats are packaged inside milk fat globules surrounded by a membrane known as the milk fat globule membrane (MFGM). This membrane contains bioactive proteins, lipids, enzymes, and immune factors.
Standard infant formula lacks MFGM. But some newer formulas now contain bovine MFGM, such as Enfamil Enspire:
- Enfamil Enspire
- Similac 360 Total Care
MFGM supplementation provides some functional benefits like MFGM in breastmilk. But the specific proteins and lipids in bovine MFGM still differ from human MFGM in breastmilk. So while a beneficial innovation, bovine MFGM enrichment alone does not make formula equivalent to breastmilk.
The Bottom Line
No commercial infant formula fully matches the comprehensive nutritional package of breastmilk. However, some come closer than others:
Closest to breastmilk:
- Formulas with HMOs + MFGM (Enfamil Enspire, Similac 360 Total Care)
- Organic dairy formulas with added DHA/ARA
Not equivalent substitutes for breastmilk:
- Standard cow’s milk formula
- Partially hydrolyzed formula
- Soy formula
- Goat milk formula
For therapeutic uses only:
- Extensively hydrolyzed formula
- Amino acid-based formula
While no formula fully replicates breastmilk, some of the newest formulas are incorporating innovations like HMOs and MFGM to try to come closer compositionally. However, breastmilk remains the gold standard when it comes to infant nutrition in the first 6 months. Whenever possible, breastfeeding is still recommended as providing the most complete nutrition for babies. But for mothers who require an alternative to breastmilk, newer formulas with HMOs and MFGM provide the closest match nutritionally based on our current knowledge. Research continues to reveal new components of breastmilk, which may lead to additional innovations in infant formula in the future.
References
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