Associations of breastfeeding with childhood autoimmunity, allergies, and overweight: The Environmental Determinants of Diabetes in the Young (TEDDY) study

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BACKGROUND: Breastfeeding has beneficial effects on numerous health outcomes.

OBJECTIVES: We investigated whether breastfeeding duration is associated with the development of early childhood autoimmunity, allergies, or obesity in a multinational prospective birth cohort.

METHODS: Infants with genetic susceptibility for type 1 diabetes (n = 8676) were followed for the development of autoantibodies to islet autoantigens or transglutaminase, allergies, and for anthropometric measurements to a median age of 8.3 y (IQR: 2.8-10.2 y). Information on breastfeeding was collected at 3 mo of age and prospectively thereafter. A propensity score for longer breastfeeding was calculated from the variables that were likely to influence any or exclusive breastfeeding. The risks of developing autoimmunity or allergy were assessed using Cox proportional hazards models, and the risk of obesity at 5.5 y of age was assessed using logistic regression with adjustment by the propensity score.

RESULTS: Breastfeeding duration was not associated with a lower risk of either islet or transglutaminase autoimmunity (any breastfeeding >6 mo, adjusted HR: 1.07; 95% CI: 0.96, 1.19; exclusive breastfeeding >3 mo, adjusted HR: 1.03; 95% CI: 0.92, 1.15). Exclusive breastfeeding >3 mo was associated with a decreased risk of seasonal allergic rhinitis (adjusted HR: 0.70; 95% CI: 0.53, 0.92; P < 0.01). Any breastfeeding >6 mo and exclusive breastfeeding >3 mo were associated with decreased risk of obesity (adjusted OR: 0.62; 95% CI: 0.47, 0.81; P < 0.001; and adjusted OR: 0.68; 95% CI: 0.47, 0.95; P < 0.05, respectively).

CONCLUSIONS: Longer breastfeeding was not associated with a lower risk of childhood (islet or transglutaminase) autoimmunity in genetically at-risk children but was associated with decreased risk of seasonal allergic rhinitis and obesity at 5.5 y of age.


  • Sandra Hummel
  • Andreas Weiß
  • Ezio Bonifacio
  • Daniel Agardh
  • Beena Akolkar
  • Carin A Aronsson
  • William A Hagopian
  • Sibylle Koletzko
  • Jeffrey P Krischer
  • Åke Lernmark
  • Kristian Lynch
  • Jill M Norris
  • Marian J Rewers
  • Jin-Xiong She
  • Jorma Toppari
  • Ulla Uusitalo
  • Kendra Vehik
  • Suvi M Virtanen
  • Andreas Beyerlein
  • Anette-G Ziegler
  • TEDDY Study Group
External organisations
  • Technical University of Munich
  • Dresden University of Technology
  • National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix
  • Pacific Northwest Diabetes Research Institute
  • University of South Florida
  • Augusta University
  • Turku University Hospital
  • Finnish National Institute for Health and Welfare
  • Skåne University Hospital
  • Ludwig-Maximilian University of Munich
  • University of Colorado
Original languageEnglish
JournalThe American journal of clinical nutrition
Publication statusE-pub ahead of print - 2021 Apr 8
Publication categoryResearch