Switch to winter time, then to summer time… Every 6 months. Is this really reasonable?
Every year in the spring and fall, hundreds of millions of people around the world adjust their clocks to conform to the time change. This practice, introduced to save energy in the 1970s, raises growing questions about its consequences for human health. So, what are the health effects of the time change, and how does this biological disruption affect our overall well-being?
To understand the effects of the time change on our health, it is essential to understand a little about our internal biological clock, also known as the circadian rhythm. Our body follows a 24-hour daily rhythm, regulating various physiological processes such as sleep, body temperature, hormone secretion and alertness.
When the time change is applied, this biological clock can be disrupted. Switching from standard time to summer time (by moving the clock forward) or to winter time (by moving it back) can shift our circadian rhythm, causing a desynchronization between our internal biological clock and the constraints of our schedule.
Effects on sleep
The most immediate effect of the time change is often felt on our sleep. When we gain an hour in the fall, our sleep schedule may shift, which can disrupt sleep quality.
These sleep disruptions can lead to problems with daytime sleepiness, irritability, loss of concentration and efficiency at work. The researchers also found a temporary increase in the number of traffic accidents after the time change.
Long-term impacts
Beyond sleep disorders, the time change can have consequences on long-term physical and mental health. Several studies have suggested a transient increase in the risk of heart attacks, mood disorders (such as depression), and metabolic disorders after the change to daylight saving time.
Sudden fluctuations in brightness and day length can disrupt the production of melatonin, a hormone that regulates sleep, mood and metabolism. As a result, some people may experience symptoms similar to jet lag, even if the transition is only an hour.
Of course, the effects of changing the time vary from person to person. Children, the elderly, and those with pre-existing sleep disorders seem particularly sensitive to changes in the time.
Experts recommend a few things to make adjusting to the time change easier, including:
- Gradually adjust your sleep schedule before the time change
- Expose your body to natural light in the morning to stimulate melatonin regulation
- Avoiding caffeine and alcohol consumption before bed