A study published in the October 2009 edition of the American Journal of Clinical Nutrition (AJCN) by Dr. Michael Kramer et al. of McGill University, Montreal Canada titled, "Health and development outcomes in 6.5-y-old children breastfed exclusively for 3 or 6 months" finds no adverse or beneficial effects associated with exclusive breastfeeding for 6 months.* Part of the PROBIT study in Belarus, a clinical trial where the promotion of breastfeeding was randomized and infants were followed forward in time and assessed for various health outcomes, this study’s objective was to compare health and developmental outcomes at age 6.5 years in children who were exclusively breastfed for three months (with continued partial breastfeeding for greater than six months) and those who were exclusively breastfed for six months.
The authors randomized pregnant women into two groups: one that received breastfeeding promotion and education and one that did not. They followed the infants in time and at 6.5 years of age, they examined anthropometric measurements, systolic and diastolic blood pressure, intelligence quotient, teachers’ ratings of academic performance, parent- and teacher-rated behavior, atopic symptoms, allergen skin-prick test, and dental caries of infants exclusively breastfed infants for three months (with continued partial breastfeeding) compared to infants exclusively breastfed for six months. The authors found that the only significant differences between the two groups were in mean body mass index, triceps skinfold thickness, and hip circumference, all of which were higher in infants exclusively breastfed for 6 months.
The study’s authors concluded, "no demonstrable beneficial or adverse long-term effects on child health or exclusive breastfeeding for 6 months." Additionally, researches noted that "established benefits appear to be limited to the period of exclusive breastfeeding."
*Kramer MS, Matush L, Bogdanovich N, Aboud F, Mazer B, Fombonne E, et al. Health and development outcomes in 6.5-y-old children breastfed exclusively for 3 or 6 mo. Am J Clin Nutr 2009;90(4):1070-4.
