6 ways breast milk is basically magic, according to science

It’s undeniable that breast milk is downright incredible. From the way it adapts to meet your baby’s needs at different times to its immune-boosting qualities, breast milk deserves all the applause.

“It is incredible that your body can provide such a magical substance for your baby,” says Diana Spalding, CNM, a Motherly advisor and midwife. “It’s just more proof that we know how to mother our children intuitively.” Here are more ways the breast milk science continues to amaze us.

Learn more about the science behind why breast milk is magic

1. Mothers’ breast milk varies based on the child’s sex

Studies have shown that the breast milk mothers produce varies in significant ways based on whether they are feeding a boy or girl. Specifically, the milk produced for female offspring (across a number of different mammal groups, including humans) tends to be lower in fat and protein than that created for males.

But making this even more remarkable are the adaptations in milk for children’s sexes in different cultures: As a 2012 study published in Nature found, impoverished mothers in Kenya produced fattier, higher-quality milk for daughters versus sons—which led researchers to hypothesize this is because girls stand a better chance at raising their family’s profile through beneficial marriages.

Related: Breastfeeding helped me love and appreciate my body—finally

2. The composition of breast milk changes as baby ages

As any mom who has witnessed the first days of colostrum give way to bags and bags of expressed milk can attest, babies’ nutritional needs change as they grow—and breast milk keeps up. And these changes to breast milk continue as babies age: According to a study published in the journal Pediatrics, the fat and energy contents in milk expressed from moms who have been lactating for more than one year were “significantly increased” than the fat and energy contents in milk from moms breastfeeding younger babies.

Related: Should you pump colostrum during pregnancy?

3. Breast milk adapts when baby is sick to provide stronger antibodies

When a nursing baby comes down with a cold, research shows the numbers of leukocytes in the mother’s breast milk spikes. Even more incredible to think about is the theory about how this information is communicated from baby to mama: Although research is limited, there are some strong scientific suggestions that backwash from baby’s mouth through mother’s nipple can carry signals that indicate the need for more antibodies.

Related: Covid vaccine antibodies found in breast milk

4. Breastfeeding reduces rates of certain ailments

Studies show breastfed infants grow up to experience lower rates of asthma, and the reason why may be because the short-chain fatty acids found in breast milk are uniquely able to line infants’ colons and lead to stronger immune responses. A recent study also found that breastfeeding is associated with a 33% reduction in mortality in a baby’s first year.

Related: An element in breast milk may help prevent certain cancers

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5. An element in breast milk is designed to protect babies from allergies

A recent study from Penn State College of Medicine found that tiny molecules in most people’s breast milk known as micro ribonucleic acids (miRNAs) can help reduce the likelihood of infants developing atopic dermatitis or food allergies. It seems that breastfeeding for at least three months activates a baby’s immune system to more appropriately respond to environmental exposures, giving them better protection against what their immune system might otherwise see as a threat.

Related: There’s an antimicrobial compound in breast milk that could help formula-fed babies, too

6. Breast milk during nighttime nursing sessions promotes infant sleep

Good news for any mama ready to get her baby back to sleep ASAP after a nighttime feed: Breast milk produced in the twilight hours has higher levels of sleep-promoting nucleotides than milk expressed during the day. This finding led researchers to suggest pumping moms offer milk expressed during certain times of the day to their babies at that same time of day—because the wonders of breast milk are really only just being revealed.

While breastfeeding may not be an easy journey, it sure is comforting to remember that not only are you helping your baby grow—but you’re also working some magic while doing it.

A version of this story was originally published on October 17, 2017. It has been updated.