title: Milk immunity and reproductive status among Ariaal women of northern Kenya.
abstract: Abstract Background: The immune factors in human milk protect infants from infection and promote immune development. Evidence suggests that the production of milk-specific immunoproteins is energetically costly, making them a form of maternal investment in offspring health that is subject to life history trade-offs.
  
  
  OBJECTIVE
  This research tests the relationship between measures of reproductive effort and the production of milk immunoglobulin A (IgA) among Ariaal women, a settled northern Kenyan pastoralist population that experiences nutritional and disease stress.
  
  
  METHODS
  Two hundred and forty-three lactating Ariaal women participated in a questionnaire, anthropometric measurement and milk collection. Milk IgA was analysed using ELISA.
  
  
  RESULTS
  There was a significant U-shaped relationship between post-partum months and milk IgA, reflecting decreasing investment in the current offspring over the early post-partum period and subsequent recovery of maternal energy status near the end. There was also a significant inverse U-shaped relationship between milk IgA and parity, with high parity women showing a drop in milk IgA. In contrast, anthropometric measures of energy status were not associated with the production of milk IgA.
  
  
  CONCLUSIONS
  This research shows that patterns of reproductive investment can be demonstrated in milk IgA in the absence of measured energy changes.
authors.affiliation: Department of Anthropology, University of South Florida , Tampa, FL , USA and.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Miller
authors.forename: Daniel S
authors.initials: DS
authors.lastname: McConnell
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis* / Q000276:immunology; D007155:Immunologic Factors / Q000096:biosynthesis* / Q000276:immunology; D007223:Infant; D007630:Kenya; D007774:Lactation / Q000276:immunology; D008895:Milk, Human / Q000276:immunology*; D011795:Surveys and Questionnaires
chemical_list: D007070:Immunoglobulin A; D007155:Immunologic Factors
keywords: Human milk; Kenya; immunoglobulin A; reproductive ecology