According to the studies, if you have a large group of breastfed babies and a large group of formula-fed babies, there will be more illness in the formula-fed group, and the breastfed group will have a slightly higher IQ.
Breast milk helps to ensure that your child reaches his/her expected potential in terms of health, intelligence, etc. Formula increases your child’s chances of illness, but does not guarantee that he or she will get sick more often.
Breast milk has DHA. (“Breast milk,” 2015) Until a few years ago formula did not. DHA helps with brain function. They don’t know everything that is in breast milk yet. As they learn, they put it in formula. But everything formula is missing does affect the babies health and intelligence. (“Breast milk,” 2015)
Breast milk contains several substances that help the baby’s brain and can increase the child’s IQ over his bottle-fed peers.
Like I said previously, it contains DHA, an omega-3 fatty acid that is important for the brain. The levels of this fatty acid in breast milk depend on the mother’s consumption of omega-3 rich foods, such as fish and flax. The DHA levels are also highest in babies who are breastfed the longest.
Breast milk also has cholesterol, which is needed to make nerve tissue in the growing brain. It is high in lactose, which is broken down in the body into glucose and galactose, and galactose is a valuable nutrient for brain tissue development. We know from animal studies that the more intelligent species of mammals have greater amounts of lactose in their milk. Cow’s milk contains lactose, but not as much as human milk. Soy-based and other lactose-free formulas obviously contain no lactose at all.
Taurine, an amino acid found in breast milk, is important to the brain development. This amino acid is low in cow’s milk. Breastfeeding, itself may also benefit a child’s brain development because it varies more than the bottle-feeding experience, and because of a greater skin-to-skin contact.
A randomised study done in December 2015 revealed that breastfeeding is related to improved performance in intelligence tests. (Horta, Loret, & Victora, 2015) Breast fed infants had higher IQ levels.
CNN also did a study in 2015 and they were able to follow 68% of the participants. They observed that breastfeeding was positively associated with performance and intelligence at 30 years old, as well as with education, school achievement and higher monthly incomes. (LaMotte & CNN, 2015)
LaMotte, S., & CNN, special to (2015, March 19). Extended breastfeeding linked to higher IQ and income in study. CNN. Retrieved from http://www.cnn.com/2015/03/18/health/breastfeeding-iq-income/
Fischer, C. (2014). Master the boards USMLE step 3. United States: Kaplan Publishing.
3. Horta, B., Loret, de, & Victora, C. (2015). Breastfeeding and intelligence: A systematic review and meta-analysis. Acta paediatrica (Oslo, Norway : 1992)., 104(467), 14–9. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/26211556
4. drsearsinstitute. (2013, August 8). Comparison of human milk and formula | ask Dr Sears® | the trusted resource for parents. Retrieved July 28, 2016, from Why Breast is Best, http://www.askdrsears.com/topics/feeding-eating/breastfeeding/why-breast-is-best/comparison-human-milk-and-formula