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A mother breastfeeding her baby

Magical Ways Your Breastmilk Boosts Your Baby’s Immunity

Pinky McKay

5 minutes


Right now, with the threat of winter bugs in the Southern hemisphere and anxiety around the Corona Virus, depending where you live and what the risks are there, this can be a scary time if you have a little baby.

The good news is that if you are breastfeeding, you are providing amazing immune protection to your baby. Breast milk, this magic potion made by mothers is a living fluid that changes depending on the needs of your baby – it can seal your newborn’s gut against potentially harmful bacteria, viruses and allergens; it can boost your growing baby’s immunity by producing antibodies to bugs your baby is exposed to; and it can change in composition depending on whether your baby is hungry, thirsty, or going through a growth spurt.

The thing is, if you are infected with any illness, your baby has already been exposed before your own symptoms become obvious. However, as you produce antibodies to viruses that your body is fighting, your baby will receive these germ fighting substances through your milk. This is protective to your baby.

Breastfeeding not only helps protect your baby against illnesses from you but to illnesses from other people, for instance, at child-care. If your baby is exposed to bacteria and viruses (even if you aren't exposed), the transfer of his saliva to your breast will trigger your own lymphatic system to produce antibodies to those bugs and help protect your child.

This is why, by continuing to breastfeed even if you catch a virus (although you might wear a mask if you are coughing or sneezing), your baby will receive the best protection.

Protection as your baby grows

The composition of breast milk and nutrients, including macronutrients, and immune factor concentrations change according to the age and development of your baby, providing the perfect food for your baby as he grows from birth through starting family foods and becoming mobile, to weaning.

For instance, studies show that the milk of mothers who have premature babies contained more calories, a greater fat concentration, more protein, sodium and secretory IgA (sIgA) than the milk of newborn term mothers.

Often referred to as baby’s first immunisation, colostrum, the sticky yellowish first ‘milk’ will maintain your newborn’s blood sugar and kick start important immunologic responses in your baby’s gut, influencing the development of normal gut flora, and preventing the growth of harmful bacteria. It also has a laxative effect that helps your newborn to pass meconium, that first black, tarry bowel motion. This reduces the reabsorption of bilirubin, reducing the risks of jaundice.

For the next day or two as your milk making hormones are triggered by the expulsion of your placenta, and a drop in progesterone (one of your pregnancy hormones) your milk will ‘come in’. It will still be a yellowish colour and is now called ‘transitional milk’ – as it ‘transitions’ from colostrum to mature milk somewhere between 3 and 5 days after birth, although this can vary.

Although your mature breast milk no longer looks ‘creamy’ and can even appear ‘watery’, however long you breastfeed, your milk will not ‘lose its goodness’ – some immune factors actually become more concentrated during the second year of life, right when your baby becomes mobile enough to play with other children and is exposed to a greater array of bugs!

Your diet can boost your breast milk

Although the nutrient stores you have laid down during pregnancy will mean that your milk is nutritious and balanced for all of your baby’s needs, there is evidence that some nutrients will be influenced by your own diet. For instance, the proportion of different fatty acids, some vitamins, such as vitamin C which is an important immune booster (however, please take care with supplements as although higher doses of vitamin C aren’t harmful, they can cause your baby to have runny bowel motions) and elements such as selenium and iodine vary according to levels in your own diet. Further research has linked ratios of fatty acids in mother’s milk and her baby’s tendency to develop certain allergies. Other studies report that levels of omega three fatty acids in mothers’ diets are linked with healthy neural development and sleep patterns in babies, as well as boosting immunity strengthening properties of breast milk.

By boosting your own diet, you will not only be boosting the nutrients in your milk, but you will be keeping yourself healthy and less likely to pass on bugs to your baby. Your baby will get ‘first dibs’ on your nutrient stores, so if you don’t eat well, you can become depleted and this will affect your energy and immunity. A good general rule for healthy nutrition is to eat a variety of natural foods - eat the rainbow (coloured vegetables and fruits) every day, drink water according to your thirst and sustain your energy with healthy whole grains and protein.

What if you are exclusively pumping or mixed feeding?

If you are an exclusively pumping Mama, your baby will still receive immune factors from your milk and by kissing your baby (how can you resist?), you will ingest bacteria and pathogens from her skin so you will make antibodies against these too.

If you are mixed feeding, even small amounts of breastmilk/breastfeeding are helpful in boosting your baby's immunity - studies show that just a teaspoon of breastmilk contains over 3 million germ killing cells!

Every bit of breast milk is protecting your baby so if you are breastfeeding but considering weaning, please reconsider continuing to breastfeed, at least through the next few months to boost your baby's immune system from these extra bugs in our environment right now.

Pinky McKay is Australia’s most recognised and respected Breastfeeding expert. She’s an IBCLC lactation consultant, best-selling author of Sleeping Like a Baby and Parenting by Heart (Penguin Random House) and creator of Boobie Foods, original all natural and organic foods to nourish breastfeeding mothers and support a healthy breast milk supply.

For tips to boost your breast milk supply, download Pinky’s FREE ebook ‘Making More Mummy Milk, Naturally’ at |