Some of you may have been told or have heard that shaking expressed BM damages it. Well someone decided to actually figure out if that's true, the results are interesting!
"There is no published evidence to support that shaking actually damages breast milk when compared to swirling. Many of the issues identified with shaking are better described as myths, and simply do not hold up when the actual shear forces are calculated. Certainly, it would be awesome if we could do an in depth study of this – have women swirl and shake milk with sensors on the hand and in the milk cup and actually measure the acceleration of the hand and then analyze the milk. I suspect however, that we wouldn’t find much damage.
...a really excellent point about this myth – “Really I think it's just one more way to make breastfeeding seem super hard and easy to mess up.” And it seems to be one piece of advice that while well meaning, may contribute to the persistent idea that human milk is fragile, easily damaged, and requires a high degree of care. It serves as one more perceived “threat” mothers (and fathers and caregivers) pose to human milk – the “if you aren’t careful, you’ll damage it and you can’t damage formula*” underlying subtext that serves to undermine breastfeeding mothers."