Drinking Milk While Breastfeeding: How Does It Affect Your Baby?

Diet is a prevalent topic for women in general, and even more so when breastfeeding. When you eat a healthy, balanced diet, it doesn’t just give your baby an excellent start to life, but you look after your own health too.

Whether you should drink milk while breastfeeding is a commonly asked question. Let’s firstly address a myth: “you need to drink milk in order to make milk”. That is simply not the case, breast milk is produced by the mammary glands in your breasts and has a dynamic (ever-changing) composition.

Why your baby (or toddler) needs calcium

You do not need to drink milk specifically in order to make milk . But, there are many nutrients in milk that are beneficial to your baby.

Calcium is an important part of your diet, because through breast milk, it helps your baby or toddler’s bones develop properly. Calcium cannot be manufactured in the body, so it is crucial to have a high enough intake to support your own needs and those of your infant via breast milk.

Other essential nutrients contained in cow’s milk include:

Vitamin A supports healthy vision in your baby. Interestingly, colostrum (that liquid gold from the first days of breastfeeding) contains twice as much Vitamin A as mature breast milk.

Vitamin B12 is important for the development of your little one’s nervous system.

Iodine is particularly important for the development of your baby’s brain and nervous system.

If you do not drink cow’s milk because you are lactose intolerant or vegan, you will need to replace the calcium , and the other vitamins present in milk with alternatives. In those cases, please consult a dietician for assistance.

Why you need calcium

You understand now why calcium is so important to your baby, but why do you need it?

When you were pregnant, the calcium needs of your baby were met by your systems extracting it from your bone mass. The greatest transfer of calcium from you to your baby occurred during the third trimester.

If you were not consuming enough calcium to replace that which you were transferring to your baby, then your body would have been at a calcium deficit at the time of birth. This is further exacerbated when, “during the postpartum period, a large amount of calcium is transferred to your baby through nursing.”

When your stores of calcium are depleted, bone mass is lost. By increasing your calcium intake , you can “increase the amount of calcium that is available to the fetus during pregnancy and the infant while breast-feeding.”

This is not always enough to prevent degradation of bone. However, “studies have indicated that an increased calcium intake reduces, and in some cases counteracts, the reduction of maternal bone during pregnancy and lactation.” That’s why you should be drinking cow’s milk if you can - while pregnant and while breastfeeding.

The link between cow’s milk consumption and a reduced rate of cow’s milk protein allergy

Allergies are an important topic for parents and their children. We want to do everything we can to protect our children from developing and then feeling the effects of those allergies.

According to the Australian Breastfeeding Association, “the most recent research suggests that excluding allergenic foods from a mother's diet during pregnancy or breastfeeding does not help prevent babies from developing allergies.”

It can be tempting to exclude foods that are commonly associated with childhood allergies. But, unfortunately, this can have the opposite result of what we intended.

A survey of 500 Swedish women and their children investigated how much cow’s milk they were drinking while breastfeeding.

There was a clear association between mother’s drinking milk and a reduced rate of a milk protein allergy in their one-year-olds. “Mothers of healthy one-year-olds consumed more cow's milk during breastfeeding than mothers of allergic one-year-olds.” There is no claim that this is a general cure for food allergies, and the mechanism at work is unclear at this stage, however the association cannot be overlooked.

There are many factors that determine if allergies occur. But, diet is one that mother’s have direct control over and is therefore very important in trying to prevent a milk protein allergy.

Does excluding cow’s milk from your diet help a colicky infant?

If you are breastfeeding a baby with colic, it may have been suggested to you to exclude cow’s milk from your diet.

Unfortunately, this is likely to work only in a minority of cases. Why is that?

“Colic is likely to be an exacerbation of normal infant crying brought about by physiological and psychosocial factors.” And because of this, there is no single treatment which is effective in resolving all cases of colic.

Excluding cow’s milk from your diet is only going to be effective treatment for colic, if it’s a milk protein allergy causing the colic. And although colic can affect up to 20% of infants, milk protein allergy tends to account for only 5% of the colic cases .

Other signs that your colicky baby might have a milk protein allergy include:

• Feeding difficulties (day, as well as night)
• Widespread eczema
• Vomiting
• Diarrhea with blood or mucus
• Failure to thrive
• First-degree family history with a genetic tendency to develop allergic diseases

If a medical professional recommends you do so, you can exclude dairy from your diet for two weeks. If all the symptoms presented resolve or improve, a diagnosis of a milk protein allergy may be confirmed.

Final thoughts on drinking milk while breastfeeding

If you can do so, then it’s beneficial to you and your baby or toddler to drink cow’s milk when you’re pregnant and breastfeeding. They may help prevent unnecessary bone degradation in yourself, and a milk protein allergy in your baby.

Please note that this article is not intended to provide medical advice. If you would like advice on this topic for your personal situation, please see your GP or child health nurse.