Detection of cortisol, estradiol, and testosterone in archaeological human hair from the Dakhleh Oasis, Egypt

Hair has become an invaluable resource in forensic, clinical, and bioarchaeological research. The unique interaction between the growing hair fiber, the hair follicle, and the endocrine system inundates the growing hair fiber with an incremental record of many of the discreet physiological processes of the body. A novel study by Webb et al. (2010) demonstrated that endogenous records of cortisol, the “stress hormone”, are capable of being extracted from archaeological human hair through a modified enzyme-linked immunosorbent assay (ELISA) technique, thus providing insight into the “invisible” stress experiences of an individual that would otherwise not be detectable through skeletal analysis. This study seeks to apply this technique to archaeological hair from 10 individuals from the Kellis 2 cemetery, Dakhleh Oasis, Egypt to evaluate patterns of cortisol production and to determine whether endogenous patterns of secretion are detectable for the steroid reproductive hormones estradiol and testosterone. All three hormones were identified in each individual within the sample, and analyses revealed that preservation was favorable. Incremental patterning of each hormone appears to reflect endogenous hormone secretion in life. Values for cortisol, estradiol in pre-menopausal females, and testosterone extracted from samples fall within reference values taken from archaeological and clinical research, though estradiol values for males and postmenopausal females exceeded projected reference values. The results of this study demonstrate that steroid reproductive hormones can be preserved in archaeological human hair, and that these hormones can be analyzed to create additional lines of inquiry into bioarcheological studies of ancient health and fertility.