YOU ARE NOT WHAT YOU EAT DURING STRESS: AN ISOTOPIC EVALUATION OF HUMAN HAIR FROM BELLEVILLE, ONTARIO

Abstract

<p>Carbon and nitrogen isotope values in sequential segments of human hair keratin provide an archive of temporal fluctuations in isotopic composition close to the time of an individual’s death. By combining stable isotope analysis with a microscopic examination of hair, this thesis explores health status prior to the death of early settlers from St. Thomas’ Anglican Church cemetery in Belleville, Ontario (1821-1874). The purpose of this thesis is to determine if there is a consistent difference in carbon and nitrogen isotopic signatures along sequentially segmented hair in individuals who have observable pathological conditions versus individuals who display no osteological evidence of pathology. Elevated nitrogen values can be associated with physiological stressors such as chronic illness, infection, or injury that affect an individual’s metabolic state. Elevated nitrogen values represent a recycling of nitrogen derived from the breakdown of existing proteins in the body and subsequent tissue repair. Results from 10 individuals indicate that δ¹⁵N values increase greater than 1‰ if an individual was suffering from a pathological condition (e.g., periostitis) or decrease by 1‰ if an individual was possibly pregnant, while δ¹³C values remained relatively constant. The variability in nitrogen values over 1‰, coinciding with less change in δ¹³C values, may be indicative of physiological stress. These results suggest that δ¹⁵N values are not only useful for studying diet, but may also be used as indicators of physiological stress.</p>