In the early hours of tomorrow, the time change will take place for the second time this year. It may seem normal to us, and almost all of Europe, to do them in summer and winter, but The reality is that only a third of the countries in the world carry out this routine. The good news is that even so, there are millions of people who have been on this regimen for more than 50 years, which has allowed scientists to have enough time and “volunteers” to evaluate its effects on the population. beyond energy savings, its first objective.
The reality is that voices against the time change are increasingly frequent. And justified. This week, the British Sleep Society, whose members include experts in neuroscience, physiology, medicine and sleep disorders from the main British universities, published an analysis in the “Journal of Sleep Research” in which advocates the abolition of time changesue occur twice a year in the United Kingdom and the restoration of permanent standard time (Greenwich Mean Time).
This recommendation is based on scientific evidence that highlights the adverse effects of the change on sleep and circadian health. «What we often don’t realize is that daylight saving time changes our schedules, moving them forward one hour, while daylight remains the same. Daylight saving time forces us all to get up and go to work or school an hour earlier, often in the dark,” said co-author Eva Winnebeck of the University of Surrey.
The authors highlight that natural daylight in the morning is crucial for maintaining an alignment of our biological clocks with day and night, which is essential for optimal sleep and general health.
“Some people even advocate switching to daylight saving time all year round. “We think this is a mistake because it would leave us with dark mornings during winter, and morning light is vitally important for keeping our biological clocks synchronized,” adds co-author Malcolm von Schantz, from Northumbria University.
Other sleep societies, such as the American one or the Canada, have also opposed year-round daylight saving time and advocate a return to year-round standard time.
Meanwhile, in Spain, the Spanish Sleep Society also has things clear and states in a statement that the time change, even if it is only one hour, unbalances the internal clock: «On our planet the hours of exposure to light solar changes throughout the day and is of great importance –the text points out–. Both the darkness of the morning and the brightness of the night delay the internal clock, producing an imbalance. This desynchronization causes people to have a tendency to go to bed later at night and wake up later in the morning.. This change causes a tendency to sleep less on workdays and sleep more on holidays, a situation that can favor poor work and school performance and, chronically, facilitate the appearance of diseases associated with the lack and poor quality of sleep. dream».
If everything indicates that the first (and biggest) victim is sleep, it is so. But from this there is a cascading effect on our health. Studies indicate that a night’s rest depends on the balance between two processes. The first is sleep homeostasis: the desire to sleep that builds from the moment we wake up until bedtime. And then the circadian rhythm, that is, the body’s natural 24-hour biological cycles. The latter is influenced by the amount of light exposure a person receives during the day.
When our internal clock changes, even by one hour, the entire process is modified and, consequently, sleep homeostasis is altered. And with it come physical and mental health problems: changes in blood pressure, depression, weight gain, digestive and heart diseases…The list goes on
A review of dozens of studies, published in “JAMA Neurology”, analyzed the consequences of time change and its effects on health and among the conclusions it points out an increase in strokes and heart attacks.
On the other hand, a 2020 study published in “PLOS” suggests that the change exacerbates mood disorders, depression, anxiety, and substance abuse. According to Adam Spira, a mental health expert at the Johns Hopkins Institute, “the consequences of lack of sleep include decreased cardiovascular health, increased diabetes and obesity, poorer mental health, lower cognitive performance, and an increased risk of car accidents.
But the effects of the time change They not only affect adults, they also have a special weight on the youngest. During puberty, melatonin (the hormone involved in regulating sleep) is released later at night, meaning teenagers have a delay in the natural signal that helps them fall asleep. Thus, at this stage of life it becomes even more difficult to get a restful rest and the consequences on physiological and mental health are more important.
This has been demonstrated thanks to scientific studies that have been carried out over the years. For nearly a decade, scientists at the University of Michigan analyzed more than 42,000 hospital admissions in the weeks after the time change. The results? Heart attacks increased by 24% during this period. Strokes increased by 8% two weeks before and two weeks after compared to other periods. They also detected an 11% increase in depressive episodes.
The question is: is all this worth the energy savings?