Comparing Formula and Breast Milk
One of the major issues to consider when deciding how to feed your baby is the quality of the food itself. Perhaps you've heard that breastfed babies get hungry sooner than bottle-fed babies. Does that mean formula sustains babies better than breast milk? Maybe you've read that formula contains more protein than breast milk. Does that mean your milk is somehow deficient?
A lesson from Little Miss Muffet
You may remember the old nursery rhyme about Little Miss Muffet, sitting on a tuffet, eating her curds and whey. Looking at curds and whey is a good place to start as you examine the differences between breast milk and formula.
Most baby formulas are derived from cow's milk (although dairy-free formulas are also available). When milk — from the breast or from a cow — is digested, it breaks down into two byproducts: curds and whey. The curd is white and rubbery, and the whey is liquid.
When cow's milk breaks down, the curd that forms is hard for human babies to digest. Breast milk, on the other hand, forms more whey than curd, and the curd is softer and more easily digested. Because the baby can digest breast milk more easily than cow's milk, he's less likely to decorate your favorite sweater with spit-up.
Formula makers are striving to make their formulas contain more whey and less curd, so they can be digested more like breast milk. Some formulas, like Nutramigen and Alimentum, are made of hydrolyzed protein, which is already broken down, so they are more easily digested than standard cow's milk or soy formulas. In all cases, breast milk is still the gold standard that formula companies are continually trying to match!
Formula and breast milk look very different; formula is creamier and looks richer than breast milk. This may lead you to believe that formula is more nutritious for your baby, but that's not the case.
One of the amazing things about breast milk is that your milk is specially formulated to have the right composition for your baby, and to contain exactly the right amounts of nutrients. Bottle-fed babies receive the exact same nutrients every time they eat. Breast milk, on the other hand, continually changes in composition so that your baby gets what he or she needs at any age.
The first liquid the breasts produce (starting a few months before the baby is born) actually doesn't even look like milk. Colostrum, which is yellow and thicker than breast milk, is a great example of how your body custom-makes the right nutrition for your baby. Here are some of its benefits:
- Colostrum has a high concentration of antibodies, especially IgA, an antibody that helps protect the lungs, throat, and intestines.
- Colostrum helps "seal" the permeable newborn intestines to prevent harmful substances from penetrating the gut.
- Colostrum is very high in concentrated nutrition.
- Colostrum has a laxative effect, which helps the baby pass the first bowel movements (and prevents newborn jaundice).
- Colostrum is low in fat, high in proteins and carbohydrates, and very easy to digest.
Within a few days after delivery, your body begins to produce mature milk that takes over the work of giving your baby the necessary ingredients for healthy growth. Colostrum is still present for around two weeks; the milk produced during this time is called transitional milk.
Breast milk contains more than 100 ingredients that the formula industry simply can't duplicate. For example, breast milk is full of antibodies that protect babies from illness and help them develop their own immune systems. Some other key differences between the ingredients in breast milk and formula include the following:
- Formula has a higher protein content than human milk. However, the protein in breast milk is more easily and completely digested by babies.
- Breast milk has a higher carbohydrate content than formula and has large amounts of lactose, a sugar found in lower amounts in cow's milk. Research shows that animals whose milk contains higher amounts of lactose experience larger brain development.
- Minerals such as iron are present in lower quantities in breast milk than in formula. However, the minerals in breast milk are more completely absorbed by the baby. In formula-fed babies, the unabsorbed portions of minerals can change the balance of bacteria in the gut, which gives harmful bacteria a chance to grow. This is one reason why bottle-fed babies generally have harder and more odorous stools than breastfed babies.
Breastfed babies often want to eat again sooner after a feeding than bottle-fed babies, which may lead you (or an outspoken relative) to conclude that you aren't producing enough milk, or your milk isn't rich enough.
Breastfed babies eat more often than bottle-fed babies because the fats and proteins in breast milk are more easily broken down than the fats and proteins in formula, so they are absorbed and used more quickly. This means that breastfed babies often have fewer digestive troubles than bottle-fed babies. (Fats in formula aren't as well absorbed, which is one reason why bottle-fed babies have more unpleasant smelling bowel movements.) However, it also means that if you choose to breastfeed, you can expect to be on call for feedings every few hours. (A bottle-fed baby, by contrast, may be able to sleep longer between feedings.)
An important consideration for breastfeeding mothers is the length of time your baby spends nursing on each breast. A baby receives thinner breast milk known as foremilk (with a lower fat content) at the beginning of a feeding, and thicker milk (with a higher fat content) after he has been nursing for several minutes. This thicker milk is called hindmilk. Allowing the baby to completely empty the breast ensures that he gets an adequate amount of hindmilk. Hindmilk has a sleep-inducing effect, resulting in the relaxed look your baby may have at the end of a meal.