Breastfeeding and cognitive development: Are breastfed babies smarter?
Breastfeeding has numerous undisputed benefits for mothers and babies alike. But when it comes to the impact of breastfeeding on the baby’s cognitive development, researchers can’t seem to come to an agreement. Is there a direct link between breastfeeding and intelligence? Do breastfed babies turn out to be smarter later in life?
In this article, we’ll look at the relationship between breastfeeding and cognitive development. We’ll also explore the health benefits of breastfeeding that make it the best source of nutrition for most newborns and infants.
Are breastfeeding and cognitive development related?
Researchers have been trying to find out whether breastfeeding has a positive impact on the baby’s cognitive development for decades. To date, there’s no conclusive evidence to suggest that breastfed babies are smarter than those who receive their nutrition from formula. Numerous studies have found a link between breastfeeding and intelligence; however, other studies claim that breastfeeding doesn’t provide cognitive benefits. Let’s take a look at both sides.
A possible link between breastfeeding and cognitive development
In 1999, American researchers conducted a meta-analysis of 20 studies to determine whether breastfed children score higher on tests of cognitive function than formula-fed children. (1) They found that children who were breastfed had significantly higher levels of cognitive function. The differences could be observed as early as six months and as late as 15 years of age. They also found that premature infants got even more cognitive benefits from breast milk than full-term infants. And, it appeared that the longer the mother breastfed the baby, the better the child’s cognitive performance later in life.
To investigate the relationship between breastfeeding and cognitive development, another group of researchers followed 1,300 children in a long-term study published in 2013. (2) They assessed the children’s receptive language skills and intelligence at ages 3 and 7. Their findings showed that breastfeeding for a longer time improves a child’s understanding of language at 3, and leads to higher verbal and nonverbal intelligence at 7.
Similar results have been found in other populations. For example, a study by a group of researchers from Korea published in 2016 found that infants who were breastfed for nine months or longer achieved significantly higher scores on cognitive tests than those who had not been breastfed. (3)
All three of these studies adjusted for a number of covariates that could influence a child’s cognitive development, such as socioeconomic status, maternal education, and home environment.
Not all studies found cognitive advantages to breastfeeding
On the other hand, several studies have been published that don’t support the notion that breastfeeding correlates to higher IQ.
For example, an early study published in 1999 that assessed children at ages 4 and 11 found that breastfed children didn’t have significant IQ advantages after adjusting for maternal IQ and parenting skills. The researchers concluded that children’s IQ is more likely to be influenced by genetic and socioenvironmental factors than breastfeeding. (4)
A 2017 study published in Pediatrics followed nearly 7,500 infants until the age of five. (5) The researchers assessed the children’s vocabulary, problem-solving skills, and behavior at nine months, three years, and five years. The only significant advantage they discovered was that children who were breastfed for at least six months had better problem-solving skills and were less hyperactive at three years old. They didn’t find any other long-term cognitive benefits of breastfeeding.
Why are the results of these studies so different?
There are several reasons for the discrepancies between studies. Each group of researchers uses different research methodologies, evaluates cognitive performance using different tests, and adjusts for different covariates.
It’s difficult to say whether breastfeeding makes babies smarter because there are so many factors at play. Researchers have to take into account genetics, socioeconomic, and psychosocial factors (like maternal IQ, family income, home environment, etc.), and the interactions that babies have with their parents – which could all influence intelligence. It could be that breastfed babies do better simply because they are more likely to grow up in a home that supports their cognitive development.
It appears that once researchers rigorously control for all important cofounders, the differences between breastfed and non-breastfed babies disappear. A systematic review of over 80 studies published in 2013 concluded that much of the reported effect of breastfeeding on cognitive development is due to confounding factors. (6)
It’s also important to mention that some studies don’t distinguish between babies who were exclusively breastfed and those who received formula supplementation. Others fail to take into account the duration of breastfeeding, which can also affect the results.
What components of breastmilk are thought to influence cognitive development positively?
Researchers in favor of the “breastfed babies are smarter” hypothesis have identified specific components of breastmilk that may influence a baby’s cognitive development.
It has been suggested that breastfeeding may contribute to cognitive development because human milk provides the nutrients that the immature brain of infants needs to develop. (3) The components of breastmilk that are thought to support the development of the newborn brain include long-chain polyunsaturated fatty acids (LCPUFAs), such as docosahexaenoic acid (DHA) and arachidonic acid (AA).
Recent studies have found evidence of other components in breastmilk that may give babies’ brains a boost.
For example, a study published in February 2020 discovered that an oligosaccharide called 2’-fucosyllactose (2’FL) found in human milk may be part of the reason why breastfed babies experience cognitive benefits.
The study showed that higher amounts of 2’FL in breastmilk in the first month of feeding resulted in significantly higher scores on cognitive tests in infants at age 2. However, higher quantities of the same component in breastmilk at six months didn’t have any influence, which suggests that exposure to 2’FL in the first month after birth is critical. (7)
Once researchers identify the components in breastmilk that aid cognitive development, formula companies can start improving their recipes. However, further research is needed to understand whether adding components like fatty acids to formula has the same benefits as those that occur naturally in breastmilk.
And let’s not discount the importance of the act of breastfeeding in furthering a baby’s cognitive development. The intimate relationship, physical contact, and bonding between mother and baby during breastfeeding may contribute to the baby’s cognitive development, albeit in an indirect way. (3)
Benefits of breastfeeding for your baby
Human milk is considered the best source of nutrition for most babies. Besides containing all the nutrients that a baby needs in the first six months of life, it also has lots of powerful antibodies to protect against viruses and bacteria.
The American Academy of Pediatrics recommends that mothers exclusively breastfeed their babies for about six months, and then continue breastfeeding while introducing some solids for one year or longer.
Breastfeeding has numerous nutritional and immunological benefits. Here are a few examples.
1. Breastfed babies may suffer fewer infections
Breastmilk may provide babies with protection against infections. A study published in 2014 that followed up with breastfed infants at six years of age suggests that breastfeeding may protect against ear, throat, and sinus infections well beyond infancy. (8)
2. Breastfed babies may have fewer allergies and respiratory diseases
Breastfeeding your baby may also help prevent allergies and respiratory diseases. A recent study published in March 2020 found a link between exclusive breastfeeding for the first three months and a lower risk of respiratory allergies and asthma when children reached six years of age. (9)
In addition, a 2007 study that surveyed 1500 Qatari infants between ages zero and five found that asthma, wheezing, allergic rhinitis, and eczema were less frequent in exclusively breastfed children. (10) These findings inspired the researchers to recommend breastfeeding as a way to reduce the risk of asthma and allergic diseases in developing countries.
3. Breastfed babies may be less likely to be obese later in life
Breastfeeding may help promote healthy weight in children. According to a 2019 report by the WHO, breastfed babies have a significantly lower chance of becoming obese by the age of nine, especially if they are breastfed for six months or more. (11) The Europe-wide study assessed 30,000 children across 16 countries and concluded that exclusive breastfeeding is a powerful shield against childhood obesity.
4. Breastfed babies may have fewer behavioral problems such as ADHD
Breastfeeding may also protect against the most commonly diagnosed neurobehavioral disorder in children: attention deficit hyperactivity disorder (ADHD).
In 2013, Tel Aviv University researchers compared six- to twelve-year-old children diagnosed with ADHD with two control groups. (12) They found that children with ADHD were less likely to have been breastfed at three months and six months of age than children in the two control groups, suggesting a protective effect of breastfeeding against ADHD.
A 2016 study has found that breastfeeding may also protect against autism and should be practiced at length to promote child development. (13)
5. Breastfeeding may transmit security to the baby
Last but not least, breastfeeding has been found to heighten a baby’s sense of security. Mothers who choose to breastfeed appear to have enhanced sensitivity during early infancy, which may foster secure attachment. (14)
Conclusion
Even though we can’t say for sure whether breastfeeding enhances cognitive development in babies, exclusive breastfeeding for at least six months is recommended because of its many health benefits for the baby.
However, it’s important to remember that breastfeeding isn’t for everyone. Some mothers aren’t able to breastfeed; others choose not to. This is a personal choice that should be respected.
At the same time, we need to make sure that mothers have all the support and education they need to make the right choices for their families.
References
(1) James W Anderson, Bryan M Johnstone, Daniel T Remley (1999). Breast-feeding and cognitive development: a meta-analysis, The American Journal of Clinical Nutrition, 70(4), 525–535, https://doi.org/10.1093/ajcn/70.4.525
(2) Belfort, M. B., Rifas-Shiman, S. L., Kleinman, K. P., Guthrie, L. B., Bellinger, D. C., Taveras, E. M., Gillman, M. W., & Oken, E. (2013). Infant feeding and childhood cognition at ages 3 and 7 years: Effects of breastfeeding duration and exclusivity. JAMA pediatrics, 167(9), 836–844. https://doi.org/10.1001/jamapediatrics.2013.455
(3) Lee H, Park H, Ha E, Hong YC, Ha M, Park H, Kim BN, Lee B, Lee SJ, Lee KY, Kim JH, Jeong KS, Kim Y. (2016). Effect of Breastfeeding Duration on Cognitive Development in Infants: 3-Year Follow-up Study. J Korean Med Sci. 31(4), 579-584. https://doi.org/10.3346/jkms.2016.31.4.579
(4) Jacobson, S. W., Chiodo, L. M., & Jacobson, J. L. (1999). Breastfeeding effects on intelligence quotient in 4- and 11-year-old children. Pediatrics, 103(5), e71. https://doi.org/10.1542/peds.103.5.e71
(5) Lisa-Christine Girard, Orla Doyle, Richard E. Tremblay (2017). Breastfeeding, Cognitive and Noncognitive Development in Early Childhood: A Population Study. Pediatrics 139 (4) e20161848. https://doi.org/10.1542/peds.2016-1848
(6) Walfisch A, Sermer C, Cressman A, et al (2013). Breast milk and cognitive development—the role of confounders: a systematic review. BMJ Open 2013;3:e003259. https://dx.doi.org/10.1136/bmjopen-2013-003259
(7) Berger PK, Plows JF, Jones RB, Alderete TL, Yonemitsu C, Poulsen M, et al. (2020) Human milk oligosaccharide 2’-fucosyllactose links feedings at 1 month to cognitive development at 24 months in infants of normal and overweight mothers. PLoS ONE 15(2): e0228323. https://doi.org/10.1371/journal.pone.0228323
(8) Li, R., Dee, D., Li, C. M., Hoffman, H. J., & Grummer-Strawn, L. M. (2014). Breastfeeding and risk of infections at 6 years. Pediatrics, 134 Suppl 1(Suppl 1), S13–S20. https://doi.org/10.1542/peds.2014-0646D
(9) Bigman, G. (2020). Exclusive breastfeeding for the first 3 months of life may reduce the risk of respiratory allergies and some asthma in children at the age of 6 years. Acta Paediatr. 2020; 00: 1– 7. https://doi.org/10.1111/apa.15162
(10) Bener, A., Ehlayel, M. S., Alsowaidi, S., & Sabbah, A. (2007). Role of breast feeding in primary prevention of asthma and allergic diseases in a traditional society. European annals of allergy and clinical immunology, 39(10), 337–343. PMID: 18386435.
(11) Rito A, I, Buoncristiano M, Spinelli A, Salanave B, Kunešová M, Hejgaard T, García Solano M, Fijałkowska A, Sturua L, Hyska J, Kelleher C, Duleva V, Musić Milanović S, Farrugia Sant’Angelo V, Abdrakhmanova S, Kujundzic E, Peterkova V, Gualtieri A, Pudule I, Petrauskienė A, Tanrygulyyeva M, Sherali R, Huidumac-Petrescu C, Williams J, Ahrens W, Breda J: Association between Characteristics at Birth, Breastfeeding and Obesity in 22 Countries: The WHO European Childhood Obesity Surveillance Initiative – COSI 2015/2017. Obes Facts 2019;12:226-243. doi: 10.1159/000500425
(12) Aviva Mimouni-Bloch, Anna Kachevanskaya, Francis Benjamin Mimouni, Avinoam Shuper, Eyal Raveh, and Nehama Linder (2013). Breastfeeding May Protect from Developing Attention-Deficit/Hyperactivity Disorder. Breastfeeding Medicine 8(4), 363-367. https://doi.org/10.1089/bfm.2012.0145
(13) Boucher, O., Julvez, J., Guxens, M. et al. (2017). Association between breastfeeding duration and cognitive development, autistic traits and ADHD symptoms: a multicenter study in Spain. Pediatr Res 81, 434–442. https://doi.org/10.1038/pr.2016.238
(14) Britton, J. R., Britton, H. L., & Gronwaldt, V. (2006). Breastfeeding, sensitivity, and attachment. Pediatrics, 118(5), e1436–e1443. https://doi.org/10.1542/peds.2005-2916
