Daily and seasonal variation in light exposure among the old order amish
JournalInternational Journal of Environmental Research and Public Health
MetadataShow full item record
AbstractExposure to artificial bright light in the late evening and early night, common in modern society, triggers phase delay of circadian rhythms, contributing to delayed sleep phase syndrome and seasonal affective disorder. Studying a unique population like the Old Order Amish (OOA), whose lifestyles resemble pre-industrial societies, may increase understanding of light’s relationship with health. Thirty-three participants (aged 25–74, mean age 53.5; without physical or psychiatric illnesses) from an OOA community in Lancaster, PA, were assessed with wrist-worn actimeters/light loggers for at least 2 consecutive days during winter/spring (15 January–16 April) and spring/summer (14 May–10 September). Daily activity, sleep–wake cycles, and their relationship with light exposure were analyzed. Overall activity levels and light exposure increased with longer photoperiod length. While seasonal variations in the amount and spectral content of light exposure were equivalent to those reported previously for non-Amish groups, the OOA experienced a substantially (~10-fold) higher amplitude of diurnal variation in light exposure (darker nights and brighter days) throughout the year than reported for the general population. This pattern may be contributing to lower rates of SAD, short sleep, delayed sleep phase, eveningness, and metabolic dysregulation, previously reported among the OOA population.
SponsorsNational Alliance for Research on Schizophrenia and Depression, NARSAD;Biotechnology and Biological Sciences Research Council, BBSRC BB/I017836/1; National Institute of Mental Health, NIMH; Nutrition Obesity Research Center, University of North Carolina, NORC P30DK072488; National Institute of Mental Health, NIMH K23MH119375-01; Brain and Behavior Research Foundation, BBRF.
Seasonal affective disorder
Identifier to cite or link to this itemhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85086884588&doi=10.3390%2fijerph17124460&partnerID=40&md5=0e6ed4384833d105c559b811bb1527fa; http://hdl.handle.net/10713/13237