The effects of ending daylight saving time on health
Context:
As several provinces move away from seasonal time changes, experts are warning against adopting permanent daylight saving time.
Members of the media may directly contact the following experts:
Rébecca Robillard (English & French)
Associate Professor, School of Psychology, Faculty of Social Sciences; & Co-Chair of the Canadian Sleep Research Consortium.
Professor Robillard is a specialist in sleep and mental health, insomnia, circadian rhythms, and the relationship between sleep and neurological and psychological conditions.
"Time is, first and foremost, a natural phenomenon defined by the position of the sun. Opting for a permanent standard time means choosing the natural time —the one alongside which our biological rhythms have evolved since the dawn of humanity — to support our health, well-being, and performance."
Stuart Fogel (English only)
Full Professor, School of Psychology, Faculty of Social Sciences; & Director of Neuroscience at the Sleep Research Laboratory.
Professor Fogel’s research focuses on the relationship between sleep, brain function, and biological rhythms. He could provide a neuroscience perspective on the effects of disrupted sleep schedules.
“DST is a misnomer. Especially in the winter, with constant DST, we would lose daylight when we need it most: in the AM. Experts agree that permanent DST has been shown to have a negative, wide-ranging impact on physical and mental health - especially youth mental health.”
Jean-Philippe Chaput (English & French)
Full Professor, Department of Pediatrics, Faculty of Medicine
Professor Chaput research focuses on the prevention and treatment of obesity in children, sleep health, screen time, and physical activity.
“By synchronizing our biological clocks with the natural light-dark cycle, we can enhance our health, boost productivity, and ensure greater safety for everyone.”
Tetyana Kendzerska (English only)
Associate Professor, Department of Medicine, Faculty of Medicine.
Professor Kendzerska specializes in sleep medicine, sleep-disordered breathing, and the relationship between sleep disorders and chronic diseases.
“While eliminating seasonal clock changes is a positive step, scientific evidence supports permanent standard time as the healthier option because morning light is essential for synchronizing our biological clocks, supporting healthy sleep and overall physical and mental health, particularly for children and adolescents, older adults, and people living with chronic health conditions; this is a complex issue that deserves consideration beyond personal preferences.”
Ashley Nixon (English & French)
Adjunct Professor, Psychology, Faculty of Social Sciences.
Professor Nixon’s research focuses on the interplay between sleep, biological rhythms, and environmental factors, exploring how light, temperature, and other environmental factors affect circadian timing, sleep quality, cognition, and human well-being.
"The debate over which time to keep is really a choice about when we get our light. Our body’s rhythms need morning light to synchronize, and without it our internal clock drifts later than work and school schedules, so we end up sleeping less. That’s why standard time, or natural time, is the healthier choice.”
Joseph De Koninck (English & French)
Emeritus Professor, Psychology, Faculty of Social Sciences.
Professor De Koninck is a leading expert in the psychophysiology of sleep, biological rhythms during sleep, and the impact of dreams, particularly nightmares, as well as in the study of sleep disorders, such as insomnia associated with mental illnesses, particularly depression.
“Shifting the period of sunlight exposure towards the evening can desynchronize our biological clock in various ways. This can disrupt our sleep, alertness, and hormone production cycles. Additionally, it can decrease the quantity and quality of sleep. The circadian system requires adequate exposure to daylight, especially in the morning and midday, with reduced exposure in the evening to synchronize properly. Too much light in the evening inhibits the production of melatonin, which is important for facilitating sleep.
In short, shifting the period of sunlight exposure towards the evening can disrupt the synchronization of our biological clock and affect our sleep, alertness, and physiological functions.”