Ana Adan: "Daylight saving time makes us function better physically and mentally."

BarcelonaA few days before entering winter time, the Spanish government has proposed this Monday to the European Union end the time change, arguing that it doesn't represent a significant energy saving and has harmful effects on people's health. At ARA, we spoke with Ana Adan, professor in the Department of Clinical Psychology and Psychobiology at the University of Barcelona (UB) and an expert in chronobiology.

Is it a good idea to end daylight saving time?

— It's a good idea if we maintain daylight saving time. It's the most synchronized with the solar cycle, the environmental time that best enables us to function physically and mentally. The important thing is that it's light when you wake up, because light activates us, and that it's dark when you go to sleep, which deactivates us.

Spanish Commissioner Teresa Ribera, in fact, has already pointed to that schedule.

— It's the best. Now it will ensure we have light in the morning, but also that in summer, when the photoperiod is longer, there isn't too much light around dinner time and when we fall asleep. Daylight saving time overexposes us to light in the evening, which makes it difficult for us to go to sleep, but the alarm clock rings at the same time in the morning, and we get less rest.

How does the time change affect us?

— It disrupts our biological rhythms, but when the change is just one hour, it has fewer effects. In healthy adults, it causes discomfort, perhaps resulting in feeling hungry or sleepy at the wrong time. Some data do suggest that the time change has seen an increase in the prevalence of cardiovascular events in people with pre-existing conditions, especially in men.

Does the effect change depending on age?

— There are studies that indicate that the change in daylight saving time has a greater effect on children and older people. People with an aging biological clock, or those with a very young one that's still organizing itself, are much more dependent on information from their environment. This makes it harder for them to reorganize with the change in daylight saving time, although the effect is still less. Children, for example, may be more irritable or sleepy at the specific time of the change.

Can we suffer health problems?

— Of effects that can generate an alteration or disorder, we only find in cases of jet lag, when there's a time difference starting three or four hours later. Then we can experience gastrointestinal problems, and affect attention and concentration...

And sleep disorders?

— Time change isn't a factor that causes sleep disorders. Children and older adults may notice that they don't sleep as well at first. But it's a temporary problem.

Would keeping the same schedule always help us rest better?

— It would make it easier, but what would really help us rest more and better would be to change our habits. The recommendation based on chronobiology is to get up in the morning and expose ourselves to ambient light, which gives us energy to function physically and mentally, and then not eat dinner late and go to bed at a reasonable time. And above all, do so without overexposure to light two hours beforehand, because otherwise we're tricking our brains, and that doesn't allow us to rest.

And would that have effects on health?

— Huge. Not getting enough sleep or not resting well are factors in premature aging and increase the risk of disease.