Human milk cortisol is associated with infant temperament

Abstract

The implications of the biologically active elements in milk for the mammalian infant are largely unknown. Animal models demonstrate that transmission of glucocorticoids through milk influences behavior and modifies brain development in offspring. The aim of this study was to determine the relation between human milk cortisol levels and temperament of the breastfed infant. Fifty-two mother and infant pairs participated when the infants were three-months old. Milk cortisol levels were assessed and each mother completed the Infant Behavior Questionnaire (IBQ), a widely used parent-report measure of infant temperament. Analyses revealed a positive association between milk cortisol and the Negative Affectivity dimension of the IBQ (partial r =.37, p < .01). No correlation was found between elevated cortisol levels and the Surgency/Extraversion or the Orienting/Regulation dimensions. Further, the positive association between increased maternal milk cortisol and Negative Affectivity was present among girls (β = .59, p < .01), but not among boys. (Although, the sex by milk cortisol interaction term was not statistically significant, suggesting that these results require replication.) Environmental factors such as maternal demographics and negative maternal affect (depression and perceived stress) at the time of assessment did not account for the positive association. The findings support the proposal that exposure to elevated levels of cortisol in human milk influences infant temperament. The findings further suggest that mothers have the ability shape offspring phenotype through the transmission of biologically active components in milk.

Sex differences in anxiety and depression clinical perspectives

“…With this said, longitudinal cohort studies suggest that low birth weight and being small for gestational age, evidence of a sub-optimal in utero milieu and fetal stress, lead to relatively greater risk of depression in adolescent (Patton et al, 2004; Costello et al, 2007; vanLieshout and Boylan, 2010), and adult (Rice et al, 2007) but not pre-adolescent (Costello et al, 2007; vanLieshout and Boylan, 2010) females. In addition, elevated levels of maternal depression and cortisol during pregnancy (Buss et al, 2012; Sandman et al, 2013) and elevated milk cortisol levels during lactation (Grey et al, 2012) have been associated with more fearful and reactive behavior in female infants and children compared to male offspring.…”

Analysis of cortisol in dog hair - a potential biomarker of chronic stress: a review

“…Generally, cortisol concentrations are assessed by sampling blood plasma or serum (Haverbeke et al 2008;Giannetto et al 2014), saliva (Kobelt et al 2003;Giannetto et al 2014), urine (Zhang et al 2017), faeces (Accorsi et al 2008;Salaberger et al 2016) and milk (Grey et al 2013).…”

“…While blood collection for cortisol in plasma should be completed within three minutes so as to not affect the cortisol concentration in plasma, saliva sampling has to be completed in less than four minutes to prevent the stress of restraint from elevating salivary cortisol concentrations (Kobelt et al 2003). Principles for milk sample collection in humans have also been described (Grey et al 2013), and faecal sample collection in dogs and cats should be done with an emphasis on cross-contamination prevention and immediate identification, labelling and storing (Accorsi et al 2008). Compared with the application of assay techniques for other types of biological sampling, hair, and in the most upto-date research, also claw (Veronesi et al 2015) sampling is a non-invasive and painless method (Ouschan et al 2013).…”

The epidemiology of observed temperament: Factor structure and demographic group differences

“…Scholars from a wide range of disciplines are empirically interested in the construct of temperament. For example, scientists who study prenatal development routinely consider temperament as an early outcome that is associated with early exposure to toxicants, (non)prescription drugs, and general stressors (Blair, Glynn, Sandman, & Davis, 2011; Grey, Davis, Sandman, & Glynn, 2013; Mayes, 2002; Richardson, Goldschrmidt, & Willford, 2008; Schuetze, Molnar, & Eiden, 2012; Weiss, Jonn-Seed, & Harris-Muchell, 2007). Cognitive neuroscientists have characterized temperament as “model area of study” for questions focused on the inter-relations of cognitive and emotional functioning (Bell & Wolfe, 2004; Henderson & Wachs, 2007; Wolfe & Bell, 2004).…”