August is National Breastfeeding month, and the CDC has released some encouraging news: between 2000 and 2010 the percentage of new mothers who chose to nurse their babies has climbed. In 2000, 35 percent of new moms nursed for six months, and 16 percent nursed for at least one year; in 2010 those numbers rose to 49 percent and 27 percent.1 This is excellent news for the health of our nation’s children, as it is well known that breastfeeding is associated with a multitude of health benefits for both the child and mother.2 Breast milk is the ideal food for infants, a naturally complex combination of nutritional and immunologic factors that cannot be replicated by formula.
Benefits of breastfeeding for the child:
- Development of the immune system:
The immune system is not yet fully active upon birth, and children are especially vulnerable to respiratory and gastrointestinal tract infections during the first two years of life. Breast milk has a “programming” effect on the immune system, providing antibodies that protect the baby from infection, antimicrobial compounds, and a variety of immunomodulatory substances that promote the maturation of immune function. Also there is new evidence that breast milk also contains healthy bacteria that may help to populate the baby’s gut flora.3 The immune benefits of breast milk translate into a reduced risk of allergies, asthma, eczema, diarrhea, respiratory conditions and ear infections in early life.
- Reduced risk of overweight in childhood:
Breast-fed infants grow more slowly and are leaner during the first two years of life compared to formula-fed infants, likely due to the lower protein content of breast milk compared to formula.4 This early slow growth may exert a long-duration protective effect, since the risk of overweight in childhood and adolescence is reduced by 22% in breast-fed infants.5
- Reduced risk of childhood leukemia.2
- Reduced risk of type 1 diabetes in childhood.4
- Enhanced cognitive development and school achievement, likely due to the DHA content of breast milk. The first year of life is a crucial time for brain development, and DHA-rich breast milk provides the building blocks for the baby’s brain.5\
- Adults who were breast-fed as infants have a reduced risk of high blood pressure, high cholesterol, type 2 diabetes, obesity, and premenopausal breast cancer.2, 5-8
Benefits of breastfeeding for the mother:
- Reduced risk of breast cancer, possibly due to the reduced exposure to ovarian hormones. A large-meta-analysis found that the risk of breast cancer decreases by 4.3 percent for every year of breastfeeding.9
- More favorable lipid, glucose and insulin levels.4
- Longer duration of breastfeeding is associated with a reduced risk of type 2 diabetes. In the Nurses’ Health Study, there was a 14-15 percent decrease in risk for each year of breastfeeding.10
- Reduced weight retention after giving birth.4
Optimal duration of breastfeeding
I agree with the recommendations of the World Health Organization, which are for exclusive breastfeeding for the first 6 months of life, with continued supplemental breastfeeding to two years. Two years is likely the appropriate age because it is the time at which the spaces between the cells lining the baby’s gastrointestinal tract close; before that time, those spaces allow the mother’s protective antibodies from breast milk to be absorbed. The new data from the CDC, although the trend is promising, suggest that breast feeding in the U.S. is not adequate – three-quarters of infants are no longer being breast-fed by their first birthday.
Proper nutrition is vitally important to health during all stages of life, and especially during the rapid cellular growth that occurs during fetal development and infancy. Early nutrition is a significant determinant of long-term health, and it starts with a woman’s nutritional status even before she becomes pregnant, followed by good nutrition throughout pregnancy and nursing, and then setting a good nutritional example for children. Breastfeeding is most protective of a child’s health when the mother is in good health.
1. U.S. Centers for Disease Control and Prevention. Breastfeeding Report Card. United States/2013. 2013. http://www.cdc.gov/breastfeeding/pdf/2013BreastfeedingReportCard.pdf. Accessed
2. Hoddinott P, Tappin D, Wright C: Breast feeding. BMJ 2008;336:881-887.
3. M'Rabet L, Vos AP, Boehm G, et al: Breast-feeding and its role in early development of the immune system in infants: consequences for health later in life. J Nutr 2008;138:1782S-1790S.
4. Gunderson EP: Breast-feeding and diabetes: long-term impact on mothers and their infants. Curr Diab Rep 2008;8:279-286.
5. Evidence on the long-term effects of breastfeeding: Systematic reviews and meta-analyses. World Health Organization; 2007.
6. Owen CG, Martin RM, Whincup PH, et al: Effect of infant feeding on the risk of obesity across the life course: a quantitative review of published evidence. Pediatrics 2005;115:1367-1377.
7. Owen CG, Whincup PH, Kaye SJ, et al: Does initial breastfeeding lead to lower blood cholesterol in adult life? A quantitative review of the evidence. Am J Clin Nutr 2008;88:305-314.
8. Martin RM, Middleton N, Gunnell D, et al: Breast-feeding and cancer: the Boyd Orr cohort and a systematic review with meta-analysis. J Natl Cancer Inst 2005;97:1446-1457.
9. Collaborative Group on Hormonal Factors in Breast C: Breast cancer and breastfeeding: collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries, including 50302 women with breast cancer and 96973 women without the disease. Lancet 2002;360:187-195.
10. Stuebe AM, Rich-Edwards JW, Willett WC, et al: Duration of lactation and incidence of type 2 diabetes. JAMA 2005;294:2601-2610.