Transition to Daylight Saving Time: Is There Sense in It? by Lyudmyla Bieliayeva, Ph.D., Associate Professor at the School of Medicine

Last Sunday of March, Ukraine switches to daylight saving time. This year, we move our clocks forward to daylight saving time at 03:00 on March 31. Due to this change, we will sleep one hour less.

Currently, there is a range of opinions against such a transition (switching). Initially, the transition to daylight saving time was motivated by economic needs - increasing the length of daylight hours allowed for energy savings. However, many European countries have now abandoned similar changes.

How does the transition to daylight saving time affect the body?

According to the views of psychophysiologists and neurobiologists, the transition is a source of not only simple household inconveniences. Research confirms: this one-hour forward jump, which occurs every March, is associated with serious negative consequences for health, including an increase in heart attacks and sleep problems in adolescents. Interestingly, the reverse transition, from daylight saving time to standard time, does not cause similar problems.

The transition to daylight saving time, which occurs every spring, has a negative impact on people's health immediately after the transition; moreover, this effect persists for eight months, as long as we live on daylight saving time.

One of the reasons for the negative impact of time change is the loss of 60 minutes of sleep because the transition from a state of sleep to wakefulness is already stressful for the body. And when such sudden changes occur, such as losing 60 minutes of sleep due to the transition to daylight saving time, the body's internal clock does not have enough time to prepare for awakening.

During this time, many people suffer from sleep deprivation. Sleep deprivation, as known, can increase the risk of developing diabetes and cardiovascular diseases. Sleep deprivation can also alter the body's response to inflammation, which is another risk factor for heart attacks.

Moreover, the transition to daylight saving time can disrupt the tone of the sympathetic nervous system, which controls the impulses that the body sends to the heart upon awakening. If a person sleeps insufficiently, their sympathetic tone increases even during sleep. And increased sympathetic tone leads to the development of heart disease.

Sharp transitions between the two standard time systems are not equivalent. Standard time corresponds most to natural lighting, when the sun is at its zenith at noon or thereabouts. In summer, from March to November, due to clock changes, the sun rises and sets later, according to the clock.

Morning light is necessary for tuning the body's natural rhythms: it wakes us up and invigorates us. Morning light also affects mood - to combat seasonal exacerbations, doctors recommend using special daylight lamps.

Although the exact reasons why light activates our bodies and positively affects mood are unknown, it may be related to the level of cortisol - the hormone that controls stress - or how light affects the amygdala - the part of the brain responsible for emotions. Teenagers may not have enough time for sleep due to a busy schedule of studies, sports, and social events.

The most significant advantage of daylight saving time is the presence of an additional bright hour of time in the evening, which can be used for sports, shopping, or dining outdoors. However, bright evening light for eight months affects your body. It delays the production of melatonin by the brain - a hormone that causes drowsiness, affecting the quality and duration of sleep.

In adolescents, melatonin is also produced later in the evening, meaning they have a natural delay in the sleep signal. Therefore, they are particularly prone to sleep problems due to additional evening lighting. A similar delay exists in people up to the age of 20 and a little more.

The impact of daylight saving time on people is also related to the geography of their residence. In one study, it was shown that people living on the western border of the time zone, where it gets brighter later in the morning, sleep less than those who live on the eastern border of the same time zone.

Residents of the western border are more likely to have problems with excess weight, diabetes, more frequent heart diseases, and breast cancer. Scientists believe that these diseases arise due to the combination of chronic sleep deprivation and circadian desynchronization. The latter means resynchronization between our biorhythms and the surrounding world. That is when work, study, or sleep depends on the clock, not on the sunrise and sunset.

How to adapt?

According to psychophysiologists, the only time that should not be changed is the sleep time. However, we still have to rebuild our circadian rhythms on the last Sunday of March.

"The adaptation period can pass quickly, or it can be prolonged. According to the idea, with a one-hour time change, adaptation takes no more than 1-2 days, but for some reason, it can take longer," says Dr. David Ernest from the Texas A&M Scientific Medical Center.

According to him, the fastest way to adapt is to immediately adjust to the new time. That is, you need to eat and go to bed at the new time on the day of the time change. Dr. Ernest also recommends preparing your body for the transition to daylight saving time in advance. For example, if a person usually wakes up at 6 in the morning, on Saturday, they should set the alarm for 6:40, on Sunday - for 6:20, and on Monday for 6 in the morning.

Additionally, the expert advises having a good breakfast and going outside for a walk or exercise. Following all these recommendations will help rebuild the central biological clock in the brain, which reacts to changes in day/night cycles, and the peripheral clock (for example, the heart), which reacts to eating and activity.

Thus, our body adapts more quickly and naturally to the changes in time, reducing the risk of feeling unwell and health problems at the beginning of the new week.