Putting stress to the test: a critical evaluation of the biological response and physical manifestation of stress in the human skeleton
Using traditional osteological methods of stress analysis, specifically skeletal lesions and growth and development patterns, this research focuses on the timing and manifestation of stress in the hard tissues of the body and the interaction between these various indicators of poor health. The Danish Black Friars cemetery population spanning the medieval and post-medieval periods (13th-17th centuries) is used for this research to explore changing health trends during a period of socioeconomic disruption and expanding urban dwelling. The results of this study show a distinct trend between the late and early post-medieval periods where stress was elevated after the Reformation (AD 1536). Additionally, females generally show higher levels of stress than males. The poorer health experienced in the post-medieval period was likely influenced by the changing living conditions of the late 16th century where urban dwelling increased in Denmark introducing new pathogens, poorer living conditions and new environmental and working stressors, all contributing to poorer health. While the overall level of stress appears to increase into the post-medieval period, the average age-at-death is higher after the Reformation suggesting that while these individuals may have been exposed to more prolonged periods of stress, they were able to adapt and survive in spite of these hardships. This research also examines the ability to analyse stress through the extraction of ancient proteins from bone. Using MircoBCA and enzyme-linked immunoassay (ELISA) analysis, it is shown that protein preservation is good in the Black Friars population and the level of protein reflects the expected fluctuations associated with the demography of the population (i.e. age, sex) and not necessarily the influence of stressors. Overall this study provides a comprehensive examination of stress from its initial biological signal through to skeletal disruption in a climate of expanding urban development and changing socioeconomics in Denmark.