What’s in Breastmilk Anyway?

By Jacquelyn Ordner BSN, RN, IBCLC, RLC

Breastmilk contains over 200 components, and that’s just what scientists have discovered so far! It is no surprise that breastmilk is the optimal food for babies, but what exactly is in it anyway?  With macronutrients, micronutrients, trace minerals, bioactive components and more, breastmilk truly is a living food!

Macronutrients

Macronutrients are nutrients that our bodies require in large amounts, typically measured in grams. Here’s a look at the average concentrations of macronutrients in 1 ounce of mature human milk. 

Carbohydrates	2.1 grams/oz
Protein	0.39 grams/oz
Fat	1.2 grams/oz
Calories (kcal)	22/ oz

Micronutrients, Vitamins, and Minerals

Micronutrients and minerals are essential for human growth and development.  It is important to note that some of these components of breastmilk can be influenced by mom’s dietary intake. Below is a list of just some of the micronutrients and minerals present, on average, in mature human milk.

Iron	23 mcg/ oz
Sodium	4.5 mg/oz
Phosphorus	4.5 mg/oz
Vitamin C	1.2 mg/oz
Vitamin A	18.2 mcg/ oz
Calcium	10.6 mg/ oz

*Note the above table is certainly not a comprehensive list of all micronutrients and minerals contained in breastmilk.

Additional Components 

Breastmilk not only contains amazing nutritional components, but also digestive enzymes, hormones, growth and development factors, antimicrobial components, and immune modulating components.  These non-nutritional agents make breast milk ideal for babies and toddlers! Here’s a brief look into some of these breastmilk super components:

Macrophages	Protect against infection by seeking and engulfing potential immune threats
Stem Cells	Essential for regeneration and repair
Secretory IgA	Most prevalent immunoglobulin in breastmilk. Anti-microbial and anti-inflammatory
Cytokines	Help modulate immune response and play a huge role in gut health.  Help protect against NEC (necrotizing enterocolitis)
Lactoferrin	2nd most abundant protein in breast milk, anti-inflammatory and antioxidant, aids in iron homeostasis, helps reduce instance of sepsis and NEC (necrotizing enterocolitis) in pre-term infants

Wow!  It’s obvious that breastmilk is truly amazing and can’t be duplicated!  How incredible is it that women’s bodies can create this incredible living food for their babies!  So, nurse or pump on mamas……you’re providing the best food on the planet, and every drop counts!

Sources

• American Academy of Pediatrics, Policy Statement. Breastfeeding and the use of human milk. Pediatrics 2005; 115:496-506.
• ESPGHAN Committee on Nutrition; Agostoni C, Braegger C, Decsi T, et al. Breast-feeding: A Commentary by the ESPGHAN Committee on Nutrition. Journal of Pediatric Gastroenterology and Nutrition 2009; 49:112-125.
•  Ochoa, T. J., & Sizonenko, S. V. Lactoferrin and prematurity: a promising milk protein?. Biochemistry and cell biology = Biochimie et biologie cellulaire 2017, 95(1), 22–30. doi:10.1139/bcb-2016-0066
• Walker A. Breast milk as the gold standard for protective nutrients. Journal of Pediatrics 2010; 156(2):Suppl. 1.
• World Health Organization http://www.who.int/topics/breastfeeding/en/