The Link Between Breastfeeding and IQ

It is indeed a pity that in recent times, breastfeeding has grabbed headlines for a slew of controversial reasons. Remember the ruckus some people made about women breastfeeding in public? Well, they got rightly trounced by the saner and the more considerate members of the public. But the flurry of mud-slinging and Twitter rants brought into the open a disturbing fact — many people are still unaware of the transformative physical and mental health benefits of breastfeeding on children.

Many doctors point out that breastfeeding helps new mommies shed the weight they have gained during pregnancy. But as men of science, they should also point out the positive link between breastfeeding and higher IQ of children. After all, this has been proved conclusively in countless studies.

The Effect of Early-Life Diet on IQ

Studies have already conclusively proved the impact of early-life diet on the brain structure of human beings. One study was conducted on two groups of adolescents who were respectively fed on a standard diet and a highly-nutritious diet in the weeks after they were born. The findings show that those adolescents who were on a high nutrient diet had significantly greater verbal IQ than the group that was on a regular diet. This study encouraged scientists to research more on the long-term cognitive benefits of breastfeeding.

Another, more recent investigation has conclusively proven the link between breastfeeding and white matter development, which is related to IQ. It demonstrated that exclusive breastfeeding is related to increase in the volume of white matter throughout the brain and that of the gray matter in the sub-cortical region. Exclusive breastfeeding is also related to the excess thickness of the parietal lobe cortical region.

Scientists have found that the duration of breastfeeding is also a critical factor that determines the mental development of the child. The longer the duration, the more is the cognitive and motor development in children. This finding was reported from a study on 2- and 3-year-old children who were breastfed for various lengths of time.

The Positive Effects of Breastfeeding Evident Well Into Adulthood

Scientists are excited to note that the positive effects of breastfeeding continue to manifest long after adolescence and well into adulthood. A decades-long study was undertaken in Brazil to determine the long-term benefits of exclusive breastfeeding. Breastfeeding information of close to 6,000 infants from various demographic groups was recorded in 1982. After 30 years, the scientists tracked down more than half of the original participants and recorded their IQ levels, educational qualifications, and incomes. The findings were startling.

Infants who were breastfed for 12 months or more scored more on IQ tests, had greater educational attainment, and earned more than those infants who were breastfed for less than a month. The positive correlation between high IQ and both greater educational attainment and income-earning potential is evident, but the findings of this study prove that it is not just breastfeeding that matters. The duration of breastfeeding plays a critical role in the cognitive development of infants.

This is the first study to examine the long-term effects of breastfeeding. The findings of this study should now encourage physicians to educate their patients on the benefits of exclusive breastfeeding at least for the first six months of the baby’s life and continuing the practice well into the first year of age. Hospitals too should encourage breastfeeding amongst new mothers.

What’s in Breastfeeding: The DHA Link

Although it is known that breast milk is rich in all the nutrients that the baby needs to mature intellectually and physically, scientists are not yet sure about the exact mechanisms at work. But they strongly believe that DHA has a role to play.

Docosahexaenoic (DHA) and arachidonic (AA) acids comprise about 20 percent of the fatty acid content in the human brain. Fatty acids are known to promote healthy neuronal growth and repair and myelination. Myelination or the increase in the volume of myelin (a protective layer of protein and fatty substances) around the neurons improves neuronal coordination and enhances brain functionality especially with regards to higher cognitive tasks. Breast milk contains an abundance of long-chain fatty acids like DHA and AA. So scientists believe that there could be a strong DHA link in the positive relation between breastfeeding and higher IQ.

The above findings have critical lateral considerations. Physicians could prescribe DHA supplements to pregnant women, so there is placental transmission of this fatty acid that would, in turn, aid the neural development in the fetus. Lactating mothers can take these supplements in prescribed doses to boost the concentration of DHA in their milk. Infant formula manufacturers should also invest in research and development to determine the optimal amount of DHA they should include in their products.

Breastfeeding, Oxytocin, and Brain Development

Some scientists also believe that the hormone oxytocin may have a role to play in facilitating brain development in breastfed babies. Oxytocin is present in small amounts in maternal milk. Animal studies suggest that oxytocin is also produced by the body in response to the suckling action of babies feeding on mother’s milk.

Oxytocin has long been associated with increased bonding and trust between the mother and the child. But according to more recent data, oxytocin is also instrumental in shaping and supporting the physical development of the central nervous system. It regulates the functions of the autonomic nervous system to ensure smooth motor functioning. Oxytocin also acts as a neural protective agent and heals scarred tissues. So it is evident that the presence and release of oxytocin in the infant body indirectly enhances his mental capabilities by promoting and supporting healthy brain development.

The findings from the above-mentioned studies leave no room for doubt that infants who have been exclusively breastfed for the first six months of their lives grow up to be more happy, healthy, and intelligent than their formula-fed peers. Mothers, are you taking note?


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Krol, K., Rajhans, P., Missana, M., & Grossmann, T. (2015). Duration of exclusive breastfeeding is associated with differences in infants’ brain responses to emotional body expressions Frontiers in Behavioral Neuroscience, 8 DOI: 10.3389/fnbeh.2014.00459

Victora, C., Horta, B., de Mola, C., Quevedo, L., Pinheiro, R., Gigante, D., Gonçalves, H., & Barros, F. (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) DOI: 10.1016/S2214-109X(15)70002-1

Image via MitarArt / Shutterstock.

Viatcheslav Wlassoff, PhD

Viatcheslav Wlassoff, PhD, is a scientific and medical consultant with experience in pharmaceutical and genetic research. He has an extensive publication history on various topics related to medical sciences. He worked at several leading academic institutions around the globe (Cambridge University (UK), University of New South Wales (Australia), National Institute of Genetics (Japan). Dr. Wlassoff runs consulting service specialized on preparation of scientific publications, medical and scientific writing and editing (Scientific Biomedical Consulting Services).
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