Winter time forever? A neurobiologist gives reasons why it is better for us than lukewarm

Changing the time disrupts the functioning of our internal clocks, so it would be better to give it up. From a biological point of view, we should maintain winter time. If we stayed in summer mode, especially in winter, we would be in permanent jet lag – Patrycja Ściślewska from the University of Warsaw told PAP.

On the night of October 25 to 26, we changed from summer to winter time. We turned the clocks back from 3 by 2, thanks to which we gain an hour of sleep. We will return to summer time on the last weekend of March.

The issue of the validity of changing the time has been controversial for years and provokes discussions among citizens, politicians and scientists. The latter have more and more arguments against the seasonal time change. Recent analyzes by scientists from Stanford Medicine (USA) have shown that giving up changing clocks twice a year and introducing permanent winter time could bring significant health benefits, including reducing the number of strokes and reducing the problem of obesity.

– Changing the time from a chronobiological point of view is not beneficial because it leads to a temporary desynchronization of clocks in our body – Patrycja Ściślewska, a neurobiologist from the Faculty of Biology at the University of Warsaw, told PAP.

As he explains, the suprachiasmatic nucleus (SCN) in the brain is responsible for our circadian rhythmicity. The name is not accidental, because it is located above the so-called optic chiasm and receives information about light directly from the eyes, straight from the retina. Thanks to this, it quickly adapts our functioning rhythm to the light surrounding us.

– The suprachiasmatic nucleus in the brain is the main clock in our body, but not the only one – we also have so-called peripheral clocks, located in other parts of the body. What it comes down to is that our stomach has its own clock, our liver also has its own clock, etc. Typically, all these clocks are synchronized. When we change the time seasonally or travel between time zones, the brain – thanks to information about light – will adapt to this change relatively quickly. However, other organs need more time for this, because the suprachiasmatic nucleus must transmit signals to them, among others: through hormones. Therefore, after the time change, we may feel worse for a few days, she explained.

When we travel to remote areas, the phenomenon of jet lag, i.e. our bad mood, may last for several days. – We may, for example, wake up in the middle of the night very hungry. This is because our brain is already in the United States, but our stomach is still in Warsaw and for it it is lunch time. However, a small time change of one hour leads to the same phenomenon, only on a smaller scale – described Patrycja Ściślewska.

If we don't feel well after the time change and we want to help synchronize our clocks, it is worth going for a walk in the morning or opening the window and looking at the sky, even if it is cloudy.

– The intensity of daylight outdoors can reach several thousand lux, while indoors it usually does not exceed several hundred. The suprachiasmatic nucleus reacts particularly strongly to blue light (with a wavelength of approximately 480 nm), which is much more abundant in the morning light than in the afternoon light, which has a warmer, yellow-red spectrum. Morning light is therefore stronger and synchronizes our biological clock more effectively – explained the UW expert.

In consultations in the Member States conducted by the European Commission a few years ago, 4 million citizens supported the abolition of time change. Three-quarters of Poles surveyed were also in favor of this solution. Also, nearly three-quarters of respondents (74.2%) were in favor of leaving summer time permanently, while supporters of winter time constituted 14.8%. total number of respondents. According to the UW expert, the result obtained at that time is not surprising, but maintaining such a solution would not be beneficial to us.

– Of course, summer time is actually more pleasant, we have longer, bright evenings, and especially in summer, it is known that it is nice to enjoy the weather longer. This is why it is understandable that the public votes to keep daylight saving time. However, from a biological point of view, we should maintain winter time – said the University of Warsaw neurobiologist.

From the perspective of the biological clock, summer time would be a problem because, for example, in winter we would have very long, dark mornings.

– In the case of permanent summer time, sunrise in winter would be much later, which would mean many people would have to get up and start work or school in the dark. Our biological clock would then be permanently shifted relative to natural light, and theoretically we should function according to the rhythm: when the light appears, we wake up; when the light disappears, a person falls asleep – emphasized Patrycja Ściślewska.

Ewelina Krajczyńska-Wujec (PAP)

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