MedicalResearch.com Interview with: Dr. Philip Tucker Department of Psychology | Yr Adran Seicoleg College of Human and Health Sciences | Coleg y Gwyddorau Dynol ac lechyd Swansea University | Prifysgol Abertawe Singleton Park | Parc Singleton Swansea | Abertawe Medical Research: What is the background for this study? What are the main findings? Dr. Tucker: Shift work, like jet-lag, is known to disrupt workers’ normal circadian rhythms (i.e. their body clocks) and their social life. It is also associated with greater risk of developing ulcers, cardiovascular disease, metabolic syndrome, breast cancer and reproductive problems. Several studies have also shown that shift workers experience heightened fatigue and sleepiness, particularly at night, and this may affect job performance and safety. However, very little is known about the long-term consequences of shift work on cognitive abilities. We followed a large sample of shift workers and non-shift workers over 10 years, testing their cognitive performance every 5 years. We found that the shift workers’ cognitive performance was lower than that of the day workers.  The difference was greatest for those who had worked shifts for more than 10 years. The shift workers’ cognitive function recovered after they quit shift work, but this recovery took at least 5 years from time that they stopped working shifts. The effects could not be attributed to poorer sleep quality among shift workers. Rather, it seems likely that the findings reflect the disruption of the shift workers’ circadian rhythms, which as been shown by other researchers to have an impact on brain structures involved in cognition and mental health over the lifespan. (more…)