Does breastfeeding increase the intelligence of babies?
Both in the scientific community and in the general population a large number of benefits are attributed to breastfeeding compared to the use of a bottle. In addition to the improvement of the immune system or the rhythm of physical growth, demonstrated by science, sometimes it is also said that breastfeeding increases the intelligence of babies .
The available research currently does not allow to affirm in a clear way that the consumption of breast milk has a direct relationship with the IQ. However, although there are contradictory data in this regard, the probability that there is a small but significant causal relationship between these two variables is high.
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Relationship between breastfeeding and intelligence
According to a meta-analysis of 17 studies on this topic by Horta, Loret de Mola and Victora (2015), there seems to be a relationship between breastfeeding and a better performance in the tests that measure the IQ.
The average of the differences, say the authors of this research, would have a value of approximately 3.44 points of CI . It is a relatively small difference but with a high statistical significance and that is maintained in later stages of development.
However, these researchers highlight the fact that the heterogeneity between studies is high, which makes it difficult to draw definitive conclusions. Even so, it should be taken into account that they tried to control the IQ of the mother, a variable that could interfere, but not the family socioeconomic level, potentially key.
Another interesting finding of this meta-analysis is that breastfeeding is not only associated with an increase in IQ, but also it could also influence academic performance in general and on the level of income during adulthood. These effects may be due directly to breastfeeding, but also to unidentified mediating variables.
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What are these effects due to?
Horta and his collaborators suggest that the link between breastfeeding and the increase in IQ does not have to be due to breast milk itself but could be determined by other factors, particularly the greater interaction between the child and his mother, that would lead to an increase in the stimulation that the baby receives.
In the event that the assumption is assumed that breastfeeding increases intelligence directly, this causal relationship could be attributed to two main facts: the strengthening of the bond between the baby and the mother and the nutritional richness of breast milk.
This food contains very beneficial nutrients for young children, such as long-chain polyunsaturated fatty acids. Its consumption could boost the development of the brain and white matter in particular, according to Isaacs et al. (2011).
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Evidence against this hypothesis
A longitudinal study conducted with a sample of more than 8 thousand families in Ireland (Girard et al., 2017) found a statistically significant relationship between breastfeeding and IQ in the early stages of life; however, it is a small increase and that it has practically disappeared when it reaches 5 years of age .
This research team found that babies who were breastfed systematically by their mothers during the first 6 months after birth showed an improvement in cognitive functions, although it was not maintained in the medium term. Therefore, in adulthood this increase in IQ would be predictably non-existent.
According to these authors, the effects found in other studies are due to insufficient control of variables. Particularly noteworthy are the educational and socio-economic levels of parents , which in turn are associated with better health, including a lower probability of tobacco use.
Other benefits of breastfeeding
Different investigations have found relationships between the early consumption of breast milk and a better functioning of the immune system. This would help prevent very varied diseases, from infections to diabetes and even sudden infant death syndrome.
In fact, the World Health Organization says that the risk of death in the first month of life is six times lower in babies who are fed with breast milk in comparison with those who are nourished exclusively by the bottle.
In any case, it is important to bear in mind that many of the studies on the effects of breastfeeding in the organism could be biased in a similar way to those we have mentioned when describing the relationship of this food with intelligence.
Finally, it is worth mentioning the relevance of the bond of attachment between mother and baby . This can have a great influence on the development of the child, especially from a psychological point of view. Breastfeeding enhances this intimate relationship, but of course there are many other elements that can do so.
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- Girard, L.C., Doyle, O. & Tremblay, R. E. (2017). Breastfeeding, cognitive and noncognitive development in early childhood: a population study. Pediatrics, 139 (4).
- Horta, B. L., Loret de Mola, C. & Victora, C. G. (2015). Breastfeeding and intelligence: a systematic review and meta-analysis. Acedia Paediatrica, 104: 14-19.
- Isaacs, E.B., Fischl, B.R., Quinn, B.T., Chong, W.K., Gadian, D.G. & Lucas, A. (2010). Impact of breast milk on intelligence quotient, brain size, and white matter development. Pediatric Research, 67 (4): 357-62.
- Lucas, A., Morley, R., Cole, T. J., Lister, G. & Leeson-Payne, C. (1992). Breast milk and subsequent intelligence quotient in children born preterm. The Lancet, 339 (8788): 261-264.
- Victora, C. G., Horta, B. L., Loret de Mola, C., Quevedo, L., Tavares Pinheiro, R., Gigante, D. P., Gonçalves, H. & Barros, F. C. (2015). Association between breastfeeding and intelligence, educational attainment, and income at 30 years of age: a prospective birth cohort study from Brazil. The Lancet: Global Health, 3 (4): 199-205.