Breastmilk Confirmed as Sleep Aid

Christina Larmer


We've long known how fantastic breastmilk is for developing bubs. It contains a powerful mix of diverse components that are vital to newborns, boosting their immunity, offering protection from everything from asthma and allergies to SIDS and obesity, and even promoting intelligence. But did you know, breastmilk may also be a weary mother’s best friend?

According to a growing body of research, human milk contains all the ingredients needed for bub to get a good night’s sleep – starting with the fat content. While looking into the stem cells in breastmilk, researchers at The University of Western Australia discovered that the fat content of mothers’ milk, which naturally rises during a feed, continues to rise for half an hour after a baby has fed, before it starts to fall.

This has exciting implications for tired mums, says lactation expert Kate Mortensen, manager of the Australian Breastfeeding Association’s Lactation Resource Centre.

“We have always suggested that if your baby is unsettled – if you’ve cuddled her, changed her nappy and she’s still not settled – and it’s half an hour after a feed, put her back to the breast,” she says. “Now, with this new research, we have an indication of why this works – because the baby is getting this higher-fat milk.”

We also know that breastmilk contains a range of hormones, including oxytocin, prolactin, melatonin and cholecystokinin, which all help relax mother and baby, says Kate. Sleeping is a complex issue in this respect, she says. “For example, melatonin, the sleep hormone, is undetectable in breastmilk during the day and peaks during the night, but we don’t know why. It possibly provides another stimulus to train the baby’s sleep-wake cycle.”

Timing is everything

Even more intriguing is research undertaken overseas, which has shown that the time you feed your baby may also be pivotal in her getting a good night’s rest. Spanish scientists have studied samples of breastmilk taken from healthy mothers at different times of the day, and found that the concentrations of its components can vary significantly over a 24-hour period.

Of particular interest here are components that are called nucleotides. These are the building blocks of DNA and are also known to have a role in exciting and relaxing the nervous system, having an effect on sleep. The Spanish researchers found concentrations of sleep-inducing nucleotides to be stronger after dark than during the day, and for this reason they believe breastmilk should be fed fresh.

“You wouldn’t give anyone a coffee at night, and the same is true of milk,” says lead researcher Dr Cristina Sánchez. “It has day-specific ingredients that stimulate activity in the infant, and other night-time components that help the baby to rest. It is a mistake for the mother to express the milk at a certain time and then store it and feed it to the baby at a different time.”

Expressing mums

That’s all very well and good, but what does this mean for mothers who can’t give their babies breastmilk fresh from the breast? While Dr Sánchez suggests they take note of the time they express milk, freeze it, then give it at the same time the following day, Kate is not convinced.

“I think a mother is doing really well to express then give it to her baby at any time, but to try and give the same milk at the same time of day, that’s too much to worry about and I don’t think it’s going to make a huge amount of difference,” she says.

“It’s always interesting to find out more about breastfeeding and how special it is, but there are so many other things in breastmilk that induce sleepiness in a baby that I think mothers need not add that extra stress to their lives.”

Instead, Kate says we need to remember that giving breastmilk at any time puts bub in good stead. “We’re only starting to understand all the special things about breastmilk,” she says. “Breastmilk is amazingly complex and there are so many interactive elements that all work together.

If you can’t feed your baby directly from the breast, then expressing your milk is the next best thing, and by doing that you’re really doing a great job.”

Tips to help your baby sleep

While there’s no doubt that feeding breastmilk direct from the source is a wonderful way to relax both mum and bub, Kate says that if you can’t give breastmilk fresh, there are plenty of other sleep-inducing options open to you. “There are other techniques that you can use that would be helpful, like having a nice bedtime routine in the evening,” she says. Here’s just some of what the latest research shows us:

Sleep routines do work. A Philadelphia study has found that infants put in a regular routine before bed (a warm bath, followed by a massage and then quiet activities such as cuddling and singing) sleep better than others. Routines, the researchers say, promote a more relaxed, stress-free environment.

But don’t be too strict

It’s also important to be emotionally receptive to your baby’s needs, say researchers at Penn State University in the US. They found that parents who pay attention to their children’s cues and respond appropriately (using soft, gentle encouragement) are more effective at getting infants to sleep than those who sternly enforce a routine. We also know that babies will start to fuss or fidget, lose interest in play or wipe their eyes when they need sleep. Learn to read your baby’s signals and act on them so she doesn’t become overtired.

Try massage

A simple massage can make a big difference. In the US, University of Miami researchers have found infants massaged for 15 minutes before bed each day for a month soon learn to fall asleep better than those who are not. Other studies show that massaged infants tend to cry less, sleep better and have lower stress levels. See page 62 for more on the benefits of touch.

Try a top-up feed

If all else fails, take heed of the Wollongong University research and give your baby a second feed 20 to 30 minutes after the first. The extra fat in the milk may be all she needs to drift off to sleep and to stay slumbering longer.

How breastmilk changes

We’ve long known that the make-up of breastmilk changes over time as your baby grows and her energy, nutrition and other needs change. When breastmilk first ‘comes in’ (a few days after bub’s birth), it’s called colostrum and is typically thicker, more concentrated and yellowish in colour. It’s also packed with just the right protein and antibodies your newborn needs to protect her from disease, and it also has the highest concentration of sleep-inducing nucleotides.

After a couple of weeks, mature breastmilk replaces the colostrum. This is thinner and whiter in appearance, but is still packed with all the essentials that your growing baby needs, including proteins, fats, carbohydrates and micronutrients.

However, during the first few weeks of lactation, the nucleotide concentration falls by about 50 per cent, which may explain why your baby starts to sleep less! Your body will continue to produce enough milk to suit her needs. If you are worried that she is not getting enough, try feeding her more often to stimulate the milk-making tissues, boosting your milk supply.

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The National Health and Medical Research Council recommends babies be exclusively breastfed until around six months of age, with breastfeeding to continue alongside appropriate first foods until at least 12 months of age. While breastfeeding is the ideal way to nourish your baby, we recognise that not all mums are able to do so. If you have any concerns about your breastfed or bottle-fed baby, see your child health nurse or GP.