Benefits for brain and psychological development

Will breastfeeding help my baby’s brain develop?

Evidence suggests breastfeeding can benefit your baby’s brain. Studies have linked breastfeeding with higher IQ scores, better motor skills, and a lower risk of attention-deficit/hyperactivity disorder. There are also psychological benefits, as breastfeeding can calm an upset baby and reduce the pain from medical procedures. Breastfeeding helps to strengthen the bond between mother and baby, allowing optimal growth and development.

A) How the brain develops

These images show the dramatic increases in the size and complexity of a baby's brain before and after birth. (Courtesy of Dr. David van Essen, PhD, Washington University School of Medicine, St. Louis, and Dr. Terrie E. Inder, MBCHB, Brigham and Women's Hospital, Boston.)

The human brain quadruples in weight between birth and four years of age when it reaches 90% of its adult size. It is only fully mature in the mid-twenties (Dekaban 1978).

Brain cells are produced from the 6th week after conception. These cells must move into the correct position, mature, develop connections with other cells and then prune them to stabilize networks. Brain maturation is completed in early adulthood when it has about 85 billion brain cells (neurons), each connected to about 1,000 other cells, creating a network of trillions of connections (Herculano-Houzel 2009). By comparison, a cat has 300 million neurons.

As the brain develops, brain cells become coated with a greasy, white substance called myelin, allowing them to work properly. Myelin is first deposited in the brain in the second trimester and continues into a person’s 20s (Volpe 2017). Specific parts of the brain also grow until this age (Pujol 1993).

B) The benefits of breastfeeding for brain development

1) Brain function

The majority of studies of breastfeeding and long-term brain development suggest that children who breastfeed for longer than six months have better memory retention, language skills and brain function (Bar 2016; Horta 2018; Hou 2021; Ip 2007; Kramer 2008; Lenehan 2019; LeWinn 2020; Soled 2020).

Studies show that compared with infant formula-fed babies, breastfed babies have been reported to better understand words and language, analyze information, and solve problems using both language-based and non-language-based reasoning (Belfort  2013; Choi 2018; Turner 2019).

Breastfed children have been reported to have better motor skills (Grace 2017).

2) Behaviour

Breastfed babies have been shown to have a lower risk of developing attention-deficit/hyperactivity disorder and lower risk of being diagnosed with autism spectrum disorder (Bar 2016; Hof et al. 2020; San Mauro Martin 2019; Soled 2020; Tseng 2018; Tseng 2019). 

Children and adults have been shown to have fewer behavioural disorders when breastfed and benefits increased with increasing breastfeeding duration (Poton 2018; Speyer 2021). 

3) Mood

Breastfeeding appears to have long-term benefits for mood.

Breastfed babies appear to be more attuned to happy faces than those with fearful or angry expressions (Krol 2015a; Krol 2015b). Breastfeeding has been reported to reduce peer problems, neurotoicism, anxiety, and negative moods and to increase optimism and agreeableness (Turner 2019).

Being breastfed as a baby appears to decrease the risk of anxiety (Orengul 2018) and depression (Huang 2019) in older children and improve mental health in adolescence (Oddy 2010) and adulthood (Lewinsohn 1997).

C) How breastfeeding helps brain development

By breastfeeding, babies receive optimal nutrition, have a better collection of gut microbes such as bacteria, viruses, and fungi (microbiome), have fewer infections, and may experience less harmful stress. All of these can have a major role in supporting the optimum development of our complex brain and nervous system (Bull-Larsen 2019). 

1) Optimum growth of the brain tissues

Breast milk supports brain growth and development by providing ideal energy, building blocks for growth (amino acids, fatty acids, minerals), hormones, health-promoting microbes, and bioactive factors such as stem cells and microRNA

Researchers have found that when compared with infant formula-fed babies, breastfed babies have increases in brain size, in thickness of the grey and white matter of the brain, and connectivity (Bauer 2019; Ou 2016). The amount of these differences increases as the duration of breastfeeding increases (Krol 2018; Solis-Urra 2019).

In one study, babies who were exclusively breastfed for three months had better myelin coverage of brain cells than babies who were fed infant formula (Deoni 2017). The same study showed better brain performance in breastfed babies.

2) Minimizing harmful stress 

a) Decreasing the risk of infection and reducing inflammation

Breast milk prevents infection and reduces inflammation which can stress and injure the developing brain.

Breastfeeding may reduce the risk of seizures with fever (Mitsuda 2019).

b) Decreasing pain

Babies, and in particular sick or premature ones, sometimes have to undergo painful procedures. Various options have been used to decrease their pain. Breastfeeding is as good as or better than the following at decreasing pain (Graf 2020; Reece-Stremtan 2016):

  • Numbing agents 
  • Sweet-tasting solutions 
  • Giving pain medication before procedures 
  • Talking to babies
  • Holding babies
  • Swaddling 

Breast milk placed in the mouth of a premature baby can help reduce pain (Collados-Gómez 2018; Graf 2020).   Babies are especially attuned to the smell of breast milk and exposure to it can shorten crying and lower levels of stress hormones (cortisol) during painful procedures (Gellrich 2021; Zhang 2018).

c) Helping mothers respond to the baby’s needs and promoting bonding

A dyad is one thing that has two parts. This term has been used to nicely describe the relationship between mothers and babies (Vestal 1982). In some ways, a mother and her baby are like a single organism linked psychologically and  biologically. Breastfeeding supports and strengthens this bond (Peñacoba 2019; Villar 2020). When this link is weakened, babies may experience harmful stress that interferes with normal brain development and function.

Breastfeeding requires that mothers understand and respond to their babies’ hunger signs. Breastfeeding mothers appear to be more responsive to their babies and the longer the period of breastfeeding, the more responsive the mother becomes. This promotes secure emotional attachment of the baby to the mother and decreases harmful stress.   

Breast milk components change during the day and night. These variations may be providing nutrients when they are most needed by the baby, teaching and supporting the baby’s internal clock, and synchronizing the mother’s and baby’s body.

For example, breastfeeding mothers and babies have similar patterns of rises and falls in their blood levels of a particular hormone (cortisol) during the first year of life (Jonas 2018). This relationship is reduced in infant formula-feeding pairs.

3) The act of breastfeeding and the effect on the brain

The act of breastfeeding may also influence brain development.

Breastfed babies are generally in contact with more of the mother’s skin than when fed with most other feeding methods. The mother’s skin smells familiar and is always the same temperature and exposure to it can calm the baby. The mother’s skin may give the baby helpful microbes, which are known to have a role in healthy brain development. This benefit may work directly on the brain, through the promotion of beneficial hormonal pathways, or through changes in the baby’s genes (Chambers 2017; Lester 2018).

References

Bar S, Milanaik R, Adesman A. Long-term neurodevelopmental benefits of breastfeeding. Curr Opin Pediatr. 2016 Aug;28(4):559-66
 
Bauer CE, Lewis JW, Brefczynski-Lewis J, et al. Breastfeeding Duration Is Associated with Regional, but Not Global, Differences in White Matter Tracts. Brain Sci. 2019 Dec 30;10(1):19

Belfort MB, Rifas-Shiman SL, Kleinman KP, et al. Infant feeding and childhood cognition at ages 3 and 7 years: Effects of breastfeeding duration and exclusivity. JAMA Pediatr. 2013 Sep;167(9):836-44

Benoit B, Newman A, Martin-Misener R, et al. The influence of breastfeeding on cortical and bio-behavioural indicators of procedural pain in newborns: Findings of a randomized controlled trial. Early Hum Dev. 2021 Mar;154:105308

Bull-Larsen S, Mohajeri MH. The Potential Influence of the Bacterial Microbiome on the Development and Progression of ADHD. Nutrients. 2019;11(11):E2805

Chambers J. The Neurobiology of Attachment: From Infancy to Clinical Outcomes. Psychodyn Psychiatry. 2017 Winter;45(4):542-563

Choi HJ, Kang SK, Chung MR. The relationship between exclusive breastfeeding and infant development: A 6- and 12-month follow-up study. Early Hum Dev. 2018 Oct 3;127:42-47
 
Collados-Gómez L, Ferrera-Camacho P, Fernandez-Serrano E, et al. Randomised crossover trial showed that using breast milk or sucrose provided the same analgesic effect in preterm infants of at least 28 weeks. Acta Paediatr. 2018 Mar;107(3):436-441
 
Dekaban AS. Changes in brain weights during the span of human life: relation of brain weights to body heights and body weights. Ann Neurol. 1978 Oct;4(4):345-56
 
Deoni S, Dean D 3rd, Joelson S, et al. Early nutrition influences developmental myelination and cognition in infants and young children. Neuroimage. 2017 Dec 19. pii: S1053-8119(17)31080-7

Gellrich J, Breuer AS, Han P, et al. Central nervous system processing of floral odor and mother's milk odor in infants. Chem Senses. 2021 May 18:bjab024
 
Gozy S, Naveed S, Waqas A, et al. Breastfeeding Status is not Associated With Risk for Autism Spectrum Disorder: A Systematic Review and Meta-Analysis JAACAP 2017: 56(10); S262-3 
 
Grace T, Oddy W, Bulsara M, et al. Breastfeeding and motor development: A longitudinal cohort study. Hum Mov Sci. 2017 Jan;51:9-16 

Graf T, Duffey E, Spatz D. Development of an Interprofessional Policy on the Use of Human Milk and Breastfeeding for Pain Relief. Adv Neonatal Care. 2020 Sep 30

Harrison D, Reszel J, Bueno M, et al. Breastfeeding for procedural pain in infants beyond the neonatal period. Cochrane Database Syst Rev. 2016 Oct 28;10:CD011248 

Heikkilä K, Sacker A, Kelly Y, et al. Breast feeding and child behaviour in the millennium cohort study. Arch Dis Child 2011;96:635–42.

Herculano-Houzel S. The human brain in numbers: a linearly scaled-up primate brain. Front Hum Neurosci. 2009 Nov 9;3:31

Hof MV', Ester WA, van Berckelaer-Onnes I, et al. Do early-life eating habits predict later autistic traits? Results from a population-based study. Appetite. 2020 Sep 21:104976

Horta BL, de Sousa BA, de Mola CL. Breastfeeding and neurodevelopmental outcomes. Curr Opin Clin Nutr Metab Care. 2018 Jan 30 

Hou L, Li X, Yan P, et al. Impact of the Duration of Breastfeeding on the Intelligence of Children: A Systematic Review with Network Meta-Analysis. Breastfeed Med. 2021 Jun 1

Huang T, Yue Y, Wang H, et al. Infant Breastfeeding and Behavioral Disorders in School-Age Children. Breastfeed Med. 2019 Mar;14(2):115-120
 
Ip S, Chung M, Raman G, et al. Breastfeeding and maternal and infant health outcomes in developed countries. Evid Rep Technol Assess. 2007(153):1-186
 
Jonas W, Bisceglia R, Meaney MJ, et al. The role of breastfeeding in the association between maternal and infant cortisol attunement in the first postpartum year. Acta Paediatr. 2018 Jul;107(7):1205-1217
 
Kramer MS, Aboud F, Mironova E, et al. Breastfeeding and child cognitive development: new evidence from a large randomized trial. Arch Gen Psychiatry. 2008 May;65(5):578-84
 
Krol KM, Grossmann T. Psychological effects of breastfeeding on children and mothers. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 2018 Jun 22
 
Krol KM, Monakhov M, Lai PS (Krol et al 2015a). Genetic variation in CD38 and breastfeeding experience interact to impact infants' attention to social eye cues. Proc Natl Acad Sci U S A. 2015 Sep 29;112(39):E5434-42
 
Krol KM, Rajhans P, Missana M (Krol et al. 2015b). Duration of exclusive breastfeeding is associated with differences in infants' brain responses to emotional body expressions. Front Behav Neurosci. 2015 Jan 22;8:459
 
Lenehan SM, Boylan GB, Livingstone V, et al. The impact of short-term predominate breastfeeding on cognitive outcome at 5 years. Acta Paediatr. 2019 Sep 13

Lester BM, Conradt E, LaGasse LL, et al. Epigenetic Programming by Maternal Behavior in the Human Infant. Version 2. Pediatrics. 2018 Oct;142(4):e20171890

LeWinn KZ, Bush NR, Batra A, et al. Identification of Modifiable Social and Behavioral Factors Associated With Childhood Cognitive Performance. JAMA Pediatr. 2020 Sep 21;174(11):1–11

Lewinsohn PM, Zinbary R, Seeley JR, et al. Lifetime comorbidity among anxiety disorders and between anxiety disorders and other mental disorders in adolescents. J Anxiety Disorders 1997; 11(4):377-394

Mitsuda N, Hosokawa T, Eitoku M, Fujieda M, Suganuma N; Japan Environment and Children's Study (JECS) Group. Breastfeeding and risk of febrile seizures in infants: The Japan Environment and Children's Study. Brain Dev. 2019 Nov;41(10):839-847 

Oddy WH, Kendall GE, Li J, Jacoby P, et al. The long-term effects of breastfeeding on child and adolescent mental health: a pregnancy cohort study followed for 14 years. J Pediatr. 2010 Apr;156(4):568-74
 
Orengul AC, Tarakcioglu MC, Gormez V, et al. Duration of Breastfeeding, Bottle-Feeding, and Parafunctional Oral Habits in Relation to Anxiety Disorders Among Children. Breastfeed Med. 2018 Nov 9
 
Ou X, Andres A, Pivik RT, et al. Voxel-Based Morphometry and fMRI Revealed Differences in Brain Gray Matter in Breastfed and Milk Formula-Fed Children. AJNR Am J Neuroradiol. 2016 Apr;37(4):713-9
 
Peñacoba C, Catala P. Associations Between Breastfeeding and Mother-Infant Relationships: A Systematic Review. Breastfeed Med. 2019 Aug 19
 
Poton WL, Soares ALG, Oliveira ERA, et al. Breastfeeding and behavior disorders among children and adolescents: a systematic review. Rev Saude Publica. 2018 Feb 5;52:9 
 
Pujol J, Vendrell P, Junqué C, et al. When does human brain development end? Evidence of corpus callosum growth up to adulthood. Ann Neurol. 1993 Jul;34(1):71-5
 
Reece-Stremtan S, Gray L. ABM Clinical Protocol #23: Nonpharmacological Management of Procedure-Related Pain in the Breastfeeding Infant, Revised 2016. Breastfeed Med. 2016 Nov;11:425-429

San Mauro Martin I, Sanz Rojo S, Garicano Vilar E, et al. Lifestyle factors, diet and attention-deficit/hyperactivity disorder in Spanish children - an observational study. Nutr Neurosci. 2019 Sep 3:1-10

Soled D, Keim SA, Rapoport E, et al. Breastfeeding Is Associated with a Reduced Risk of Attention-Deficit/Hyperactivity Disorder Among Preschool Children. J Dev Behav Pediatr. 2021 Jan 1;42(1):9-15

Solis-Urra P, Esteban-Cornejo I, Cadenas-Sanchez C, et al. Early life factors, gray matter brain volume and academic performance in overweight/obese children: The ActiveBrains project. Neuroimage. 2019 Aug 26:116130

Speyer LG, Hall HA, Ushakova A, et al. Longitudinal effects of breast feeding on parent-reported child behaviour. Arch Dis Child. 2021 Apr;106(4):355-360
 
Tseng PT, Chen YW, Stubbs B, et al. Maternal breastfeeding and autism spectrum disorder in children: A systematic review and meta-analysis. Nutr Neurosci. 2019 May;22(5):354-362
 
Tseng PT, Yen CF, Chen YW, et al. Maternal breastfeeding and attention-deficit/hyperactivity disorder in children: a meta-analysis. Eur Child Adolesc Psychiatry. 2018 Jun 15
 
Turner S, Mayumi Maruyama J, Matijasevich A, et al. Breastfeeding and the Development of Socio-Emotional Competencies: A Systematic Review. Breastfeed Med. 2019 Oct 29
 
Vestal KW. A proposal: primary nursing for the mother-baby dyad. Nurs Clin North Am. 1982 Mar;17(1):3-9

Villar J, Ochieng R, Staines-Urias E, et al. Late weaning and maternal closeness, associated with advanced motor and visual maturation, reinforce autonomy in healthy, 2-year-old children. Sci Rep. 2020;10(1):5251 

Volpe JJ, Inder T, Darras B, et al. Neurology of the newborn. 6th Edition. Philadelphia: Saunders/Elsevier; 2017
 
Zhang S, Su F, Li J, et al. The Analgesic Effects of Maternal Milk Odor on Newborns: A Meta-Analysis. Breastfeed Med. 2018 Jun;13(5):327-334