Breastmilk: Stir it, Swirl it, Shake it, Bop it?

Have you ever heard of the myth that shaking expressed breast milk denatures the proteins within it? Well, shake away mamas (and papas and grandmas and nannies)!

We know that breast milk separates after expression, but what’s the best way to incorporate it back together? Shake it? Swirl it? Run a paint mixer through it? Go for a three mile jog with it in our back pocket (actually, that would mix and warm it… I may be onto something here)? The short answer: do whatever you gotta do to get those fats and proteins all back to their original liquid gold concoction. Well, maybe not the paint mixer...

If you Google the question of shake vs stir, you’ll undoubtedly run across many different websites and experts saying never to shake breast milk, for various reasons. The main reason, the biggest claim? Manually shaking denatures proteins and damages cells. The truth? Nah. It doesn’t. At least that’s to say, there isn’t any scientific evidence that has been published to support the claim that it does.

The main factor considered into this debunking of the myth was primarily the force that it would take to denature a protein. The thing is, hormonal proteins and immune proteins (such as breast milk) are much more difficult to denature than those found in nutritional proteins. Sugars attach to these particular proteins (called bioactive infant circulation) to protect them from denaturing, and other proteins are encased within fat globules. I’ve created an image here for demonstration.

Probably wouldn’t be easy to get through those sugars and fats to get to those proteins, would it? You’d need either a) something very sharp (which aren’t found in bottles containing breast milk), or b) brute force. So unless you’re shaking your breast milk with the force of Mike Tyson, shake away, y’all. Just try not to be Mike Tyson.

References: https://biomarkersandmilk.blogspot.com/2014/08/swirled-or-shaken-does-shaking-actually.html?m=1&fbclid=IwAR21tABcnbxR9zqRJnqmUKaib3gaJ1hLfr1wUYSQM4pRJITJM3i8l8tWt6o

http://www.yourbreastfeedingguidebook.com/blog/2015/6/4/the-milk-shaking-controversy

https://masonbottle.com/blogs/news/118344964-new-parents-cross-this-off-your-list-of-things-to-worry-about