▲ The plump 'Michelin arm' of babies like tires is an attractive point that can only be seen in infancy.

Kaka (Taemyung), who was born healthy at 3.93kg, is still growing as an excellent baby that exceeds the graph in the growth chart (the curve showing the distribution of physical measurements such as height and weight of children and adolescents). When I go for a walk with Kaka, the elders in the village scan my healthy body up and down and say one word at a time. “I feel like a general. I think mother’s milk is better.” Even though she's a cute little girl with her hair neatly combed and even a pin attached. Some people say with a sad expression, “I see that the baby is fat, so it looks like he is eating formula.” Why do the opinions of 'good breast milk' and 'disappointing formula' coexist when it comes to the appearance of a chubby child? Is breast milk really good, and formula milk is unconditional?


  • Breast anatomical changes due to breastfeeding

▲ An illustration depicting the breasts and ducts of a lactating woman analyzed by ultrasound. ⓒInternational Breastfeeding Journal

During puberty, when secondary sexual characteristics develop, and before menstruation, women experience a more bloated and painful feeling than usual. It is the mammary glands of the chest that cause these changes. When the baby begins to suck on the nipple, the nerve impulse triggers the release of 'prolactin'. The hormone prolactin causes the mammary glands to make milk. After that, when the baby sucks in earnest, the hormone oxytocin is secreted.

During pregnancy, mammary glands develop under the influence of various hormones such as estrogen and progesterone, which leads to changes in breast size. Most of them complete their growth before the 22nd week of pregnancy, and the degree of growth varies from mother to mother. At the end of pregnancy, the volume of the breast increases by an average of 145 mL, and increases by 211 mL by the first month of lactation. Breast growth rate is known to be related to the concentration of 'placental lactogen (hPL)', a hormone secreted from the third week of fertilization.

Donna Geddes, a professor at the University of Western Australia in Australia, published a study in the Journal of Anatomy in 2005 that investigated the relationship between the anatomical structure of the breast and the amount of breast milk. First, the research team recruited 21 mothers who were 1 to 6 months old after giving birth who were 'bare mothers (breastfeeding only)' and analyzed the anatomical structures such as the number of ducts and the distribution of adipose tissue using ultrasound images.

Twenty-one mothers produced an average of 387 g and 407 g of milk in their left and right breasts over 24 hours. The average number of major ducts was 9.6 and 9.2 on the left and right, respectively, and the average diameter was 1.9 mm and 2.1 mm, respectively. Synthesizing the study, Professor Geddes explained, "The anatomical structure, such as the amount of mammary tissue, the number and average diameter of ducts, was not related to the ability to produce milk."

  • Advantages of breast milk that it is 'white sea fruitless'

▲ The positive effects of breastfeeding on babies and mothers have been proven through various studies. 

The World Health Organization (WHO) and the Korean Academy of Pediatrics and Adolescents recommend that you wear 'full hair' for at least 6 months unless there is a special reason. It is not an exaggeration to say that human history is because breast milk has been scientifically proven to have many advantages. A few of the numerous studies will be briefly introduced.

First of all, it has a positive effect on the health of the child. The beneficial intestinal microflora of the mother is passed on to the baby through breast milk, creating a healthy intestinal microbiome ecosystem in the child's intestine. This means that your immunity is strengthened. The longer the period of puberty, the lower the risk of asthma in children. There is also a result that breast milk causes epigenetic changes in the child, which reduces the secretion of 'cortisol hormone', resulting in a child with less stress. It is even said that the longer you breastfeed, the better your child's intelligence (IQ) development.

There are also benefits to the health of the mother. Women who breastfeed are less likely to die from heart disease, stroke and cardiovascular disease. Breastfeeding for more than 12 months has a lower risk of death. It can also help you lose weight gained during pregnancy. During her pregnancy, the woman burns 340,000 more calories than usual, while breastfeeding nine months after her birth requires a whopping 670,000 calories. The diet effect of breastfeeding is clear if you can overcome the ‘hungry if you turn around’ situation.

Meanwhile, it has also been found that breastfeeding after vaccination against COVID-19 can provide a child with “passive immunity” against COVID-19. In January, researchers at Amherst University in the United States reported that they detected antibodies to SARS-CoV-2 in stool samples from mothers who were breastfed after vaccination with COVID-19. The conclusion of the study published in March in the Journal of the American Medical Association (JAMA Pediatrics) is the same. In this study, researchers at the University of Amsterdam in the Netherlands measured the amount of antibody delivered through breast milk depending on the type of vaccine. As a result, it was concluded that the antibody delivery effect of mRNA (microRNA)-based vaccines such as Pfizer and Moderna was superior to vector virus-based vaccines such as AstraZeneca and Janssen.

Joseph Larkin, a professor at the University of Florida in the US, said, "Newborns' immune systems are not yet fully developed, so it is difficult for them to fight an invading virus on their own. It's the same principle as getting a vaccine to prevent it."


  • Are the benefits of breastfeeding exaggerated?

▲ Most mothers give up breastfeeding because of environmental factors, not because formula is better than breast milk. A series of studies highlighting the benefits of breast milk can be stressful for these mothers. In the long term, some studies have found that the effects of breastfeeding on children are not significantly different from that of formula feeding. ⓒPxhere

How many mothers decide not to breastfeed because formula is better than breast milk? Numerous obstacles such as the mother's health status, the newborn's metabolic disorders, allergies, and the shape of the nipples will make it difficult to breastfeed. In fact, among my child-rearing comrades, there were many cases where I tried to breastfeed, but gave up on breastfeeding because of ‘the child refused to suck’, ‘the amount of breast milk was small’, and ‘the nipple was flat’. For this reason, it is easy to cause an uncomfortable situation when women are forced to breastfeed on the basis of various scientific merits. Moreover, there are studies that evaluate that some of the benefits of breast milk are not without exaggeration.

A 2017 study published in Pediatrics found that breast milk had minimal positive effects on children's intellectual and cognitive development. Researchers at the University of Dublin in Ireland evaluated whether breastfeeding had an effect on the children's cognitive abilities, such as problem solving and vocabulary, in 7,478 children aged 3 and 5 years. To eliminate the socioeconomic level bias, children from similar backgrounds were selected, and surveys were conducted when the children reached 3 and 5 years of age.

As a result of the study, children who were breastfed for more than 6 months scored higher on the problem-solving ability test when they reached the age of 3 compared to those who were fed formula. However, there was no significant difference in cognitive ability at the age of 5 years. In the long term, the conclusion is that breastfeeding has no significant effect on children's cognitive abilities.

The conclusion of a research team at Ohio State University in the United States, published in the international academic journal ‘Social Science & Medicine’ in 2014, is similar. The research team analyzed the effects of breastfeeding on 1,773 children aged 4 to 14 years who were raised by the same parent, but with different feeding patterns, such as the first mother and the second mother (only formula-fed). No long-term benefits of breastfeeding were found in 10 of 11 items, including obesity, attachment, compliance, vocabulary, academic achievement, and asthma. One item in which breast milk's benefits were found is the likelihood of developing asthma.

Professor Cynthia Collen, who led the study, said, “Some of the existing studies that emphasized the benefits of breast milk did not consider differences due to socioeconomic circumstances, so the benefits of breastfeeding were exaggerated. If not, we'll have to look more closely at other important aspects, such as 'what stresses breastfeeding puts on mothers'."

On the other hand, there are studies that question the myth that breastfeeding is economical, one of the main advantages of breastfeeding. It is a view that must be taken into account that the majority of women today find it difficult to reconcile work and breastfeeding. In this study, the researchers analyzed the adolescent longitudinal survey data and found that mothers who breastfed for more than 6 months suffered a more severe loss of income than mothers who did not breastfeed or breastfed for a shorter period of time. This is a study that casts doubt on the conventional wisdom that breast milk is “free” because it is made by the mother’s body, unlike formula milk, which has to be purchased at a cost.

  • How to feed is an important consideration

▲ There is also a study result showing that the way a child is fed, not whether it is breast milk or formula, affects a child's intelligence. Ultimately, it is up to the mother and child to decide all of this. ⓒPixabay

The breasts of women who have undergone pregnancy and childbirth can never be the same as they used to be. As it is a change that occurs in the mother's body, it is the mother and child's responsibility to decide on breastfeeding or formula feeding, not the people around them. Advice from those around you can sometimes add to the fatigue of mothers who are suffering from chronic fatigue due to childcare. Once you have decided on the direction, it is a matter of considering how to breastfeed. Based on the interesting findings, I would like to end this article by asking a question to fellow parenters.

The study was published in the European Journal of Public Health in 2012. In this study, the researchers investigated the relationship between mothers' well-being and children's intelligence according to feeding habits in 10,000 children aged 5 to 14 years. The researchers divided the participants into three groups: a group that fed regularly according to a schedule, a group that failed to meet the schedule, and a group that breastfed according to the child's request. We then assessed the well-being of these mothers and the intelligence level of their children according to the feeding regimen.

The results of this study give contradictory implications. The well-being level of mothers in the group who fed regularly according to the schedule was highly rated. Fatigue decreased, maternal confidence and the joy of parenting greatly increased. Regular breastfeeding also lowered the risk of postpartum depression. On the other hand, the IQ scores of children who were fed regularly were 4-5 points lower than those who were fed on demand. If we compare the IQ difference of 4-5 points to a class of 30 children, it is the difference between a child who is in the middle of the class and a child who is in 10th place. The researchers added that as this is the first study to analyze the effects of breastfeeding on mothers and children, more follow-up studies are needed to confirm a clear association.

As such, parenting is a series of choices. I am thinking about how to proceed with breastfeeding with regard to my life and the intelligence of the child. Is it time to delete ‘Baby Time’, an application that records feeding time and sleep?