As a British study reveals, the quality of rest is partly achieved by not being exposed to light during rest.
Indeed, this research published in JAMA Network, highlights that “exposure to brighter light at night is associated with higher risks of disease”, citing in particular the risks of myocardial infarction, heart failure, atrial fibrillation or even stroke.
Thanks to their research carried out over almost ten years on 88,905 people over the age of 40, they established that those sleeping in a bright room had a 42% greater risk of myocardial infarction than those who slept in almost total darkness.
The team of sleep specialists led by Daniel P. Windred, from the Institute of Health and Medicine Research at Flinders University, in Bedford Park, Australia, therefore concluded that despite all the factors involved, such as diet, smoking or others, exposure to light during sleep was a factor in its own right and independent of myocardial infarction.
To explain this link between passively observed light and cardiac consequences, the researchers claim that artificial lighting disrupts the human circadian rhythm, which allows the heart rate to naturally decrease at night.
The biological clock is dysregulated, the nervous system fails to go to sleep, remains on alert, maintains a high heart rate and the production of stress hormones increases. In the long term, the effects of these phenomena are devastating: inflammation, blood clotting, premature aging of the arteries, etc.
The scientists write: “Using data collected by wrist-worn light sensors in approximately 89,000 participants, we recently observed an increased risk of cardiometabolic mortality in people exposed to brighter nights and darker days.”
