Whey & Casein In breastmilk
If you’ve done much reading about breastmilk vs formula milk its likely you’ve read about the difference between the whey-casein ratio in these milks. But did you know that the ratio of whey and casein in breastmilk changes over time?
This post is going to get a tiny bit science-y, but an understanding of breastmilk composition, and how it differs from formula milk, can help you understand why your baby may be behaving differently to those of your friends that may not be receiving breastmilk.
Whey protein is the liquid portion of your milk and makes up 90% of the protein in your milk in the early days of lactation. The whey protein is full of immune factors to provide protection for your baby. It also helps to support the growth and development of your baby’s bones, teeth and muscles. The whey protein remains liquid and is really easy for your baby to digest.
Casein protein is also important for your baby’s growth and plays a role in helping your baby build healthy bones. Casein proteins bind together in the stomach, forming curds, so is digested more slowly than whey. Casein therefore plays a role in your baby feeling fuller for longer and therefore potentially asking for less frequent feeds.
In the first few weeks with your baby the ratio of whey to casein in your breastmilk is 90:10 (90% Whey:10% Casein).
Over the coming weeks there is a gradual change to a 80:20 whey to casein ratio at around 6 weeks. Its likely that you will see this reflected in your baby’s stools with stools becoming slightly more formed, thicker and possibly less frequent.
Over the coming months that ratio continues to adjust to your baby’s needs, reaching around 60:40 or 50:50 when your baby is around 6 months old.
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Whey & Casein In Formula and cows milk
If you are needing or choosing to use a formula milk then it is recommended that only first infant milks are offered during the first year of your baby’s life. The ratio of whey to casein in first infant milks is usually around 60% whey: 40% casein.
There are many other formula milks available to buy. Some of them being described as follow on milks or milks labeled as number 2 or perhaps suitable from 6 to 12 months. It is not necessary to use a follow on milk. Continue to use a number 1 milk through the first year of your baby’s life.
Follow on milks largely exist to allow manufacturers to advertise their products as there are significant restrictions on advertising first milks.
There are also a number of products described as helping to meet different needs for you baby, perhaps thickened and described as anti-reflux, helping to reduce colic and hungry baby milks. Hungry baby milks will have higher volumes of casein, the harder to digest protein. If you are considering using one of these milks I would suggest you consult with your healthcare provider or an infant feeding specialist.
You can see this post for more information about types of formulas.
When your baby is one year cows milk can be provided instead of formula milk. Cows milk is around 20% whey: 80% casein.
