Breast Milk and Brain: The Influence of Iodine and Neurotrophic and Growth Factors on Children’s Neurodevelopment-A Secondary Analysis

Pantea  Nazeri; Najmeh Hamzavi  Zarghani; Zhale  Tahmasebinejad; Mohadese  Dashtkoohi; Mehdi  Hedayati; Parvin  Mirmiran; Mamak  Shariat; Fereidoun  Azizi

doi:10.18502/jfrh.v19i3.20062

Pantea Nazeri Breastfeeding Research Center, Family Health Research Institute, Tehran University of Medical Sciences, Tehran, Iran
Najmeh Hamzavi Zarghani Department of Pediatrics, Faculty of Medicine & Dentistry, College of Health Sciences, University of Alberta, Edmonton, AB, Canada
Zhale Tahmasebinejad Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Mohadese Dashtkoohi Maternal, Fetal and Neonatal Research Center, Family Health Research Institute, Tehran University of Medical Sciences, Tehran, Iran
Mehdi Hedayati Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Molecular Biology, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Parvin Mirmiran Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Mamak Shariat Maternal, Fetal and Neonatal Research Center, Family Health Research Institute, Tehran University of Medical Sciences, Tehran, Iran
Fereidoun Azizi Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/jfrh.v19i3.20062

Keywords: Breast Milk Iodine Concentration; Brain-Derived Neurotrophic Factor; Insulin-Like Growth Factor-1; Child Neurocognitive Development

Abstract

Objective: This study targeted to investigate the potential role of breast milk iodine concentration (BMIC), insulin-like growth factor-1 (IGF-I), and brain-derived neurotrophic factor (BDNF) during the early stage of lactation in child neurocognitive development.

Materials and methods: In this secondary analysis, we examined 122 breastfeeding mothers and their healthy children, all of whom were breastfed for at least six months. Levels of BDNF, IGF-1, and BMIC were assessed in breast milk samples obtained between the third and fifth days after lactation began (before any iodine supplementation intervention). Three-year-old children were administered the Bayley-III screening test to assess their cognitive, motor, and language development.

Results: The median (interquartile range) concentrations of iodine, BDNF, and IGF-1 in breast milk during the starting few days of lactation were 285.0 (181.0-366.0) µg/l, 0.59 (0.52-0.76) ng/ml, and 12.5 (9.6-18.3) ng/ml, respectively. The mean (standard deviation) cognitive, motor, and language scores were 101.0 (10.8), 93.4 (14.6), 100.1 (13.5) and, respectively. Linear regression models revealed a negative relation between breast milk iodine and children’s cognitive development ((β unadjusted = -0.004 (P = 0.010); β adjusted = -0.003 (P = 0.024)). However, no associations were found between breast milk BDNF and IGF-1 and cognitive, language, or motor scores in three-year-olds.

Conclusion: Our findings indicate that early exposure to iodine, BDNF, and IGF-1 in breast milk, measured prior to iodine supplementation, has no substantial association with neurodevelopment in three-year-old children. The weak negative association between BMIC and cognitive scores may reflect prenatal iodine status, warranting further research to explore long-term effects of supplementation.