Now, what cooler than being cool?
Ice cold!
I can’t hear ya! I say what’s, what’s cooler than being cool?
Ice cold!
Alright alright alright alright alright alright alright alright alright alright alright alright alright alright alright alright!

Lyrics for “Hey Ya!” by Outkast

Keeping it cold is also the advice if you want to keep the bactericidal activity of breastmilk intake (JPGN 2012; 55: 146-49).  This study examined the effects of freezing from 48 healthy donors who provided samples of fresh breastmilk.  Bactericidal activity was determined by thawing breastmilk (in duplicate) and innoculating with bacterial strains and then comparing growth in breastmilk compared with control samples.

Freezing at -20 degrees celsius (C) for 1 month did not effect the bactericidal activity of breastmilk against either E coli or P aeruginosa.  In contrast, when samples were stored for three months, freezing at -80 degrees C was protective of this activity whereas -20 degrees C was not.

So if you are storing breastmilk for longer than 1 month, keep it cold if you can.

Related blog entry:

Long-chain polyunsaturated fatty acids, breastmilk, and infant cognition