Is it true that breastfeeding increases a child's intelligence?

It is widely believed that feeding with mother's milk not only strengthens the child's immunity, but also increases his intelligence. We decided to check whether this is supported by scientific data.

Information that mother's milk increases child's intelligence can be found at websites many large institutions health, private clinics And centers, as well as specialized Media. The authors of such publications claim that “health and intelligence come with mother's milk" and that "children who have been breastfed for a long time are more successful in adulthood,” some people wonder: “Breastfed children = smart children?" Popular this topic also on parents forums.

Mother's milk, according to data According to the WHO, "ideal foods for babies" are "safe and harmless and contain antibodies that help protect [baby] from many common childhood diseases." WHO experts recommend feed children up to six months exclusively with breast milk, and then, after introducing complementary foods, continue to breastfeed the child until two years or more. However, few people currently follow this recommendation - only one in three babies are exclusively breastfed for the first six months of life. However, breastfeeding is beneficial influences on the health of not only the child, but also the mother. A year of lactation reduces the risk of all types of breast cancer by 4.3%, ovarian cancer by 27%, and uterine cancer by 11%.

One of the largest research, who studied the connection between the type of feeding and the level of intelligence of the child, were carried out back in 1999 at the University of Kentucky Medical Center (USA). Scientists selected 20 scientific papers on the development of children raised on breast and bottle feeding, and calculated that children who received mother's milk show results 3-5 points higher in IQ tests than their peers who were fed formula. Scientists explained this difference by the absence of two substances in milk formulas: docosahexaenoic and arachidonic acids. These substances belong to the group of unsaturated fatty acids and are important for brain development. The researchers noted that mixtures of European manufacturers contain these substances, but most often are not included in American products, and recommended that manufacturers include them in the composition. In 2002, experts from the US Food and Drug Administration (FDA) listened to scientists, and now many American mixtures contain these components. And according to directive The EU and European manufacturers are required to add both substances to their products. 

In 2015, specialists from the Federal University of Pelotas in Brazil let down results of 30 years of observation of almost 6,000 local residents. The scientists had data on the type of feeding of 3,493 people from this group. In addition, the researchers took into account many additional parameters: monthly household income, age and education level of the mother, smoking during pregnancy, body mass index, type of birth (vaginal or cesarean section), gestational age of the child (number of weeks spent in the womb), birth weight and race. After analyzing the life successes of children who became adults, the researchers reported that on average, breastfeeding for 12 months increased IQ by 4 points, and salary by 340 Brazilian reais (about 6,300 rubles at the average exchange rate for 2015), and these children also studied almost a year more than their peers. At the same time, researchers note, that their findings are limited - perhaps better intellectual indicators are associated with the fact that breastfeeding mothers generally took better care of the child and devoted more time to his development than those who, for some reason, chose to use formula.

More conflicting results received scientists from the University of Rochester Medical Center and the University of California at San Diego (USA). They studied the intellectual development of 9,116 children aged nine to ten years. Best (by 0.3 standard deviation, for IQ it is amounts to 15 points) children who were breastfed for more than 12 months coped with tests of cognitive abilities. Those who were fed for seven to 12 months performed slightly worse than them, but better than the average (by only 0.2 deviations). Those who received breast milk from one to six months were more successful in completing tasks by 0.1 deviations. The lowest results were shown by children who at one time did not receive milk at all. However, the researchers note that "the majority of infants who did not receive breast milk were born to unmarried women (52.5%) with a high school education or no education (33%) and a total household income of less than $50,000 per year (43.9%)." In addition to cognitive functions, researchers were also interested in executive behavior and memory. Those who were breastfed for more than 12 months performed slightly worse than others on tests of executive function. Scientists have not found any patterns between memory and nutrition with mother's milk. 

Scientists from the University of Dublin, having analyzed the results of intelligence tests of 7478 children aged three to five years with different types of feeding, not found no difference in mental development. The researchers were interested in the child's skills in solving various problems, his vocabulary, behavior, hyperactivity and ability to build relationships with others. The only thing that distinguished children fed with breast milk rather than formula was that at the age of three they were calmer than their peers, who more often had signs of hyperactivity. However, by the age of five the difference disappeared completely. Scientists have concluded that a child’s development is much more influenced by the mother’s education and family income, rather than the type of diet.

The point in the discussion about the connection between the type of feeding and the intellectual abilities of the child is put study specialists from the University of Edinburgh. They were able to find pairs of siblings with different types or duration of feeding: 332 pairs were discordant on the type of feeding (one child was fed breast milk, the other on formula) and 545 pairs were discordant on the duration of breastfeeding. There were no differences in intelligence between the children. In addition to brothers and sisters, the scientists also observed other children; in total, 5,475 children from 3,161 mothers were included in the study. It turned out that the greatest influence on the development of intellectual abilities was not the type of feeding, but the IQ of the mother herself. However, this parameter most accurately predicted the type of nutrition - a mother's advantage of 1 standard deviation doubled the likelihood that her children would receive breast milk rather than formula. This may also explain the results of other studies: the higher the intelligence of the mother, the more, on the one hand, she pays attention to the development of the child and, thanks to this, ensures better development of his cognitive abilities; on the other hand, the high intelligence of a woman increases the chance of breastfeeding for her baby. Thus, children of mothers with high intelligence are more likely to receive breast milk and have high test scores, but the reason for their results is not nutrition, but the ability of the mother. “Although breastfeeding has many benefits for the baby and mother, increasing the child’s intelligence is unlikely to be one of them,” report researchers.

However, there is a group of children whose intelligence appears to be influenced by breastfeeding: children with third and fourth grades. degree prematurity. After analyzing MRI data from 180 children born before 30 weeks of gestation and weighing less than 1250 g, doctors from the USA, UK and Australia came concluded that drinking mother's milk increases the amount of gray matter in the newborn's brain. The children were monitored throughout the period until the date corresponding to their planned birth. By this time, premature infants who received at least half of their daily calories from mother's milk had a greater volume of gray matter in the deep nuclei of the brain. Seven years later, the scientists met with these children again, gave them another MRI, and also tested them on attention, memory, visual perception, achievement in language and mathematics, and motor skills. These parameters were best developed in children who received mother's milk in the first days of life.

And although different studies show different results regarding the effect of the type of feeding on intelligence, the most reliable of them seems to be a comparison of pairs of brothers and sisters in which one child received breast milk and the other did not. While studying pairs of such children, scientists did not find any pattern between the type of nutrition and intelligence. Only in premature babies does breast milk significantly improve cognitive abilities. In other cases, the mental development of the child will be primarily affected by the intelligence and social status of the mother, who, thanks to this, will take a more responsible approach to raising her offspring, including trying to feed him breast milk. However, even those scientists who did not find any patterns between nutrition type and intelligence, notethat mother's milk is the most optimal product for feeding a child, and they encourage women to resort to this method for as long as possible.

Cover image: Image by Jonathan Hammond from Pixabay

Mostly not true

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