Features

Ruled by the biological clock

A circadian rhythm acts something like an internal timer that determines how our bodies function during a 24-hour period

Get­ting rid of day­light sav­ing time is good news be­cause it causes health dis­or­ders that might only be slight but can be avoided,” says Javier Al­bares, head of the sleep unit at the Clínica Teknon in Barcelona. Older peo­ple and chil­dren are the ones who suf­fer most from such prob­lems, be­cause they have less chrono­bi­o­log­i­cal flex­i­bil­ity. The cir­ca­dian rhythm is our in­ter­nal clock, and it tracks the changes that take place in our bod­ies through­out the day.

“Our bi­ol­ogy works ac­cord­ing to these in­ter­nal clocks, which reg­u­late our sleep, our im­mu­nity, our me­tab­o­lism, our di­ges­tive sys­tem, our car­dio­vas­cu­lar sys­tem... and it will take time for them to ad­just to this change, even if it is as small as an hour,” says Al­bares. It is im­pos­si­ble for this adap­ta­tion to take place in a sin­gle day. “Twice a year, our bi­o­log­i­cal rhythm has to read­just, and it can take days to do so. For ex­am­ple, with the time change in the sum­mer, which is one that is hard­est to adapt to be­cause we sud­denly have a day that is 23 hours long in­stead of 24, we see that road and work ac­ci­dents rise, and it can cause di­ges­tive and sleep prob­lems. It has even been shown that on the Mon­day after the change in the hour, car­dio­vas­cu­lar in­ci­dents go up,” adds Al­bares.

Win­ter or sum­mer time

As for whether it is best to stick to win­ter or sum­mer time, Al­bares does not hes­i­tate in choos­ing the for­mer. In fact, at a con­gress in Barcelona last April, the Span­ish Sleep So­ci­ety came out in favour of adopt­ing win­ter time as the best op­tion for our cir­ca­dian rhythm. “If we were to stay with sum­mer time all year long, in Barcelona the sun would not come up until about 9.15 am in De­cem­ber . That would mean a lot of peo­ple would spend their first hours in the morn­ing in total dark­ness. That has im­por­tant reper­cus­sions for health and one’s mood, and causes sleep dis­or­ders or work-re­lated ac­ci­dents... It is very im­por­tant for us to have nat­ural light at the start of the day and with sum­mer time it would take too long for the sun to come up in win­ter,” says Al­bares.

With sum­mer time, how­ever, the sun would go down so late in June and July that it would keep our brains alert at night and there­fore delay the time we would go to bed. “And one of the major prob­lems we have in our so­ci­ety is that we lack two hours of sleep every night; we live de­prived of sleep and that also has reper­cus­sions on our health,” the doc­tor points out.

More day­light

While no ex­ten­sive study has been car­ried out, polls con­ducted by media out­lets sug­gest that most peo­ple would pre­fer to keep sum­mer time be­cause that would mean more day­light in the evenings in au­tumn and win­ter, and would there­fore pro­vide more leisure time.

“But what do we want? A coun­try of start-ups or a coun­try of pave­ment cafés?” asks Mo­hedano. On this point the ac­tivist for timetable re­form says that the so­lu­tion for hav­ing more day­light hours is to not adopt a time that can harm our bi­o­log­i­cal rhythms, but rather to fin­ish work ear­lier, “and that does de­pend on our pro­duc­tive ca­pac­ity and pres­sur­ing for more ra­tio­nal sched­ules.”

Ga­jardo says the UGT agrees that the issue of chang­ing timeta­bles and how we use our time should not be mixed up. “They are dif­fer­ent things. In the end, both for the peo­ple work­ing in in­dus­try and for the peo­ple work­ing in the leisure sec­tor, the sun will come up and go down at the same time,” she con­cludes.

fea­ture

8%
more accidents.
Another study in 1996 found an 8% increase in the number of road accidents, due to tiredness brought on by the change in the hour in the spring.
15 minutes
to adapt.
The best way to adapt to the change in hour is to introduce small modifications into your timetable about four days before, especially meal times and bed time.
24%
rise in heart attack.
In 2014, a study by the University of Colorado in the US revealed that in the week after the change in the hour in spring there was a 24% increase in the number of heart attacks at meal times and at bed time.

Energy saving no longer an issue

The world in 1974 was nothing like today’s world. Nowadays, offices and factories use artificial light all day long, with the electricity savings that might be made in the morning cancelled out by the costs in the evening. Meanwhile, savings in homes are relatively small. “There are no rigorous studies to tell us whether changing the hour actually leads to energy savings or not. Nevertheless, everything suggests that getting rid of daylight saving time would not make much of a difference, in part because illumination now comes from LED lights instead of incandescent light bulbs, which were used in the seventies. What’s more, lighting in homes has changed radically,” says Pep Salas, the head of smartgrid.cat.