A new study published in Jama Pediatrics[i] claims that babies given solid food in addition to breastmilk from three months of age sleep better than those who are solely breastfed. Mothers filled in monthly online questionnaires between three and 12 months, and then reported quarterly until their children were three years old. Those who were giving solids reported that babies slept longer (a peak difference of 16.6 extra minutes per night at around six months), woke less frequently (1.74 times a night instead of twice a night) and had fewer serious sleep problems than those who were exclusively breastfed until about six months. The mothers also said they had improved quality of life.
When considering the results of this study, it may be useful to refer to a recent Sleep Medicine article[ii] which raised questions about the outcomes of previous infant sleep studies based on parents’ self-reporting on the amount their babies slept. In particular, this article found that some parents over-estimated how much more a baby slept when diet was altered, and the authors of the JAMA Pediatrics study admit that “the commonly held belief that introducing solids early will help infants sleep better could have produced a reporting bias.”[iii]
Understanding normal sleep patterns
LLLGB aims to provide mothers with accurate information about breastfeeding and parenting to enable them to make informed choices and consider what is best for them and their families. The JAMA Pediatrics study raises several areas of concern.
When making decisions about infant feeding, it can help to know that it is normal for a baby to wake at night and that lots of arousals can in fact protect the baby. Understanding that “sleeping through the night” is something which will happen when the baby is developmentally ready allows women not to feel pressured into introducing solids before their baby’s digestive system can cope with them. Parental expectations on how much a baby “should” sleep can be determined by the society they live in and may not be biologically appropriate.[iv]
Why babies often wake frequently
Breastmilk is easily digested and is meant to be absorbed quickly by a baby’s digestive system. Waking to nurse frequently is a protective measure to help prevent a life-threatening sleep apnoea (a temporary inability to breathe), as infants who spend more time in a deeper sleep don’t arouse so easily.
Dr. James McKenna, Director of the Mother-Baby Behavioral Sleep Laboratory at the University of Notre Dame says: “infantile cardio-pulmonary perturbations are corrected by the infant arousing from sleep that leads to oxygenation. Arousing is an infant’s best defense against a range of potential physiological challenges”.[v]
Dr. McKenna says infants are not always waking for food, but also for non-nutritive purposes, such as to be cuddled and touched, and possibly reassured emotionally. Night waking is often determined and/or regulated “by way of changing growth, metabolic and developmental caloric requirements, and likely by the infant’s own personality characteristics”.[vi]
Why early solids can be detrimental
Breastmilk supplies all the essential nutrients a baby needs for around the first six months of life. An infant’s digestive system is designed to be ready for solid food once he has developed enough to be able to eat it on his own.
A baby’s digestive tract needs to be mature before starting solids, so the lining of his intestines is sealed against allergens (allergy producers). If given solids too early, allergens can slip through the intestinal wall into the bloodstream, resulting in the baby producing antibodies against them, potentially leading to allergies and eczema. Often a baby will automatically thrust solids back out to protect his digestive tract.
At around six months a baby starts producing adult-type enzymes needed to break down food for digestion. Having solids before they can be properly digested can cause a baby to have tummy problems and not fully absorb the nutrients.[vii]
In addition, starting a baby on solids like fruit and vegetables before he is ready can cause his iron stores to drop. This is because these foods are often low in iron and so are simply replacing breastmilk, the perfect food for babies, with ones providing fewer nutrients.
La Leche League suggests mothers look for cues that their baby is ready, such as being able to sit up, pick up food, get it in his mouth and chew without choking, which often happens around six months.[viii]
Studies have also shown that early introduction of solids, particularly of sugary foods, is an important factor behind the obesity epidemic and can lead to babies being overfed. Breastfeeding helps a baby to regulate his own appetite so that when he starts solids he may be better able to avoid over eating.[ix]
Frequent night waking to breastfeed poses a significant challenge to mother’s sleep; however, feeding a baby solids before he’s ready in the hope that he will sleep more could over-ride his instinct to wake and could create other problems.
Caring for a new baby is often tiring, independent of the way a baby is fed. It can help to try to sleep or rest when the baby does, even if it’s not a time when you would normally nap. Sitting down to breastfeed means you get a chance to relax and put your feet up.
Studies have shown that when mothers stop breastfeeding their fatigue level does not change. One US study also found that breastfeeding mothers averaged 40-45 minutes more sleep at night during the first three months than those formula feeding, even when fathers helped out with giving bottles.[x] [xi]
La Leche League GB knows that women often receive conflicting advice and information. While we recognise that it is important to ensure that recommendations are based on the best available evidence and are regularly reviewed, we continue to believe that breastmilk provides everything a baby needs up to around six months of age, and that introducing other foods before a baby is ready is not beneficial.
Babies’ individual development varies and parents are best placed to look for signs that their baby may be ready for solid foods.
Anna Burbidge for La Leche League GB, July 2018
[i] Perkin, M.R. et al. Association of Early Introduction of Solids With Infant Sleep. A Secondary Analysis of a Randomized Clinical Trial. JAMA Pediatrics, 9 July 2018. https://jamanetwork.com/journals/jamapediatrics/fullarticle/2686726
[ii] Rudzik, A.E.F. et al. Discrepancies in maternal reports of infant sleep vs. actigraphy by mode of feeding. Sleep Medicine, 30 June 2018. https://www.sleep-journal.com/article/S1389-9457(18)30320-4/fulltext
[iii] Perkin, M.R. et al. Association of Early Introduction of Solids With Infant Sleep. A Secondary Analysis of a Randomized Clinical Trial. JAMA Pediatrics, 9 July 2018. https://jamanetwork.com/journals/jamapediatrics/fullarticle/2686726
[iv] McKenna, J. Night waking among breastfeeding mothers and infants: Conflict, congruence or both? Evolution, Medicine, and Public Health, 2014; 1: 40-47. https://academic.oup.com/emph/article/2014/1/40/1844291
[vii] La Leche League International. The Womanly Art of Breastfeeding. 2010, 8th Edition; 248-249.
[ix] American Academy of Pediatrics. Starting Solids Too Early May Increase Obesity Risk, https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/Starting-Solids-Too-Early-May-Increase-Obesity-Risk.aspx (accessed 9 july 2018).
[xi] Kendall-Tackett, K. et al. The Effect of Feeding Method on Sleep Duration, Maternal Well-being and Postpartum Depression. Clinical Lactation, 2011; 2 (2): 22-26. http://www.uppitysciencechick.com/kendall-tackett_CL_2-2.pdf