We are often asked, “Why do you pasteurize your milk donations?” The simple answer is this: because pasteurization kills the bad while retaining the good. But that answer doesn’t always satisfy those that think breastmilk is best raw form. While generally, we agree: breastmilk is best untouched, our mission is to provide donor milk to the population of infants who are most susceptible to infection. It’s our job to provide the best nutrition while ensuring we do no harm. Both the American College of Pediatricians and the Center for Disease Control recommend pasteurized human donor milk if mother’s own milk is unavailable and that means we have a responsibility to ensure proper procedures.
Before we pasteurize milk donations, we first make sure that our donors are free of communicable diseases and are generally healthy with limited medication use. We require a blood test for all our milk donors to check for HIV, HTLV, Syphilis, Hepatitis B &C. We make sure our donors maintain lifestyles that are compatible for donation- they are a non-smoker, aren’t taking a medication that will affect a premature baby and pump and store their milk in a safe way.
But what about the milk itself? What in the milk is killed during pasteurization and what is maintained?
First, let’s talk about what is retained.
- The enzyme that destroys bacteria by disrupting their cell walls retains 75 percent of its activity. Lysozyme, with many other bioactive components, allow a baby to create their own immunity in their urinary tract. Meaning, babies fed breast milk are less likely to develop a urinary tract infection.
- Oligosaccharides, a complex chain of sugars unique to human milk are unchanged by pasteurization. You might be wondering, why are these sugars important? They exist to feed the tiny organisms that make up a baby's digestive system. In fact, some researchers believe that human milk was evolved to be more protective than to provide nutrition.
- 70 percent of the concentrated IgA antibodies are also retained through pasteurization. These are the antibodies to things like E. coli, group B streptococci and Brucella abortus, all bacteria that can be harmful, if not deadly to a preterm infant.
So, how does breastmilk change when pasteurized?
- The good news is, not much changes! Well, aside from the things we want to change like the elimination of pathogens and viruses.
- Some of you might have heard about lipase or have experienced high amounts of it in your own frozen milk, pasteurization inactivates the enzyme.
Our final step to ensure sure the milk we are sending to the most fragile infants is completely safe involves testing for potential bacteria. Each batch has a random sample checked by an independent lab that performs a 48- hour culture to check that all potential pathogens and viruses are destroyed.