Doctor Eduard Estivill lives in a state of almost daily communion with his readers; proudly displays a bundle of letters from parents from all over Spain, Europe, South America and even Australia thanking him because with his book they have taught children to sleep, and now the whole house rests, the couple works and the work has ceased to be an ordeal. He speaks with a loose and friendly verb, his gaze always fixed and a sparkle of enthusiasm in his eyes. The truth is that he appears to have slept well.
–How much do we need to sleep?
-The number of hours that give us a good vigil. The concept is more important than the quantity. We sleep to be awake: during the night the brain generates wakefulness. In fact, we know that there is a series of neurotransmitters responsible for maintaining wakefulness that are produced during the night. And until this work is completed, we do not wake up properly. The same thing happens the other way around: we make our dreams during the day. We secrete a series of substances closely linked to serotonin, a deep sleep-inducing peptide that must be generated during wakefulness.
–So there is no universal number of hours …
-The number of hours is a function of the degree of wakefulness that each one needs, which is variable. The vast majority, 90 percent of the adult population, need between 7 and 8 hours. On the other hand, a person from the age of 65 or 70 reduces their night hours to about 6, although they need more naps during the day. 5% with only 5 or 6 hours can maintain excellent wakefulness. And there is another 5 percent that would need 9-10 hours to stay in shape. The former are called short sleepers, and the others, large sleepers or long sleepers. Neither is pathological.
–The German writer Hans Magnus Enzensberger said that one of the things that most attracts his attention about Spain is how little its inhabitants sleep …
-We sleep fewer hours for purely environmental reasons. If we have dinner at 10 at night, before 12 no one goes to sleep, but the next day many people get up at 7. We must also take into account external stimuli. For example television, which greatly affects people’s habits. When I was little there would be some pictures that said: “let’s go to bed” and all the children knew that this was the moment to go to sleep.
–But, do we Spaniards sleep worse than other Europeans?
-Of course, of course. We are short sleepers. We slept about an hour less. What happens is that this sleep deficit is cumulative. If one day we lose an hour and the next day another hour, it is as if we had lost two. And this has been shown by subjecting people to tests of alert to very monotonous stimuli to measure their performance, such as a television screen or a kite, to see how long they can last without making mistakes. And it is seen that there is a geometric progression in the number of errors when sleeping less.
–Does modern life make it hard to sleep well?
-A century ago we slept an average of an hour more. As there was no light, people spent more time sleeping. In fact, the light is what informs our brain that we must rest. That is why people who work at night and have to sleep during the day have serious difficulties in falling asleep correctly.
–Can little sleep affect health?
-It has a very clear impact on wakefulness in three areas: memory loss, concentration deficit and increased irritability. This would be within the field that we call cognitive repercussion. In addition, the person who sleeps little is at greater risk of fatigue during the day. This causes a lower alert, and the lower alert means that in critical situations, such as driving, there is a greater risk of an accident.
–But regardless of this cognitive repercussion …
-People who suffer from sleeping difficulties, not so much those who sleep little, but insomniacs, have a higher risk of psychiatric illnesses.
–And organic disorders?
-That has not been proven yet, because the first sleep is almost never lost and it is where the physical repair is done, while in the second part of the night there is more mental repair.
–In some sleep disclosure book the possibility is postulated that one can shorten their sleep hours to live longer awake …
-This is a great aberration. It has no scientific basis. Sometimes they ask me in the consultation: how can I sleep fewer hours and be well the next day? This is impossible. It is as if someone asked you what to do to eat one day a month and not be hungry the other days.
– What is a good sleep?
-Perform the sleep function in a satisfactory way for the person. In essence, it would be lying down, having a period of relaxation, reading a little or listening to music or doing nothing special and having a continuous sleep. It can also be considered a good sleep to have brief awakenings during the night and that we could go back to sleep without any problem. This is rare when we are young and much more common after 50 or 55 years.
–Does sleep deteriorate with age?
-It is not that it deteriorates, it is that its structure changes. Just as a one-month-old baby cannot maintain a continuous sleep throughout the night or a continuous wakefulness during the day, the same thing happens to the elderly person. You wake up more at night, you can’t stay asleep often, and you can’t stay awake often. Therefore, the elderly person who sleeps 5 or 6 hours at night and who can take a couple of 10 to 20 minute naps during the day is a totally normal person. The problem with older people is that they spend much more time in bed than they sleep.
–What is the most common sleep disorder?
-The insomnia. Then, in terms of severity, it would be sleep apnea syndrome: snoring with respiratory arrest. And also childhood insomnia.
–Why do we sleep?
-To stay awake.
–That can be said by anyone
-But it is very important. We sleep because during sleep a series of functions are produced at the brain and cardiorespiratory level, essential to be alert the next day. The state of man is not to be awake, but to be awake and to be asleep. It is as if we wonder why we are awake. We are awake to be able to sleep and we sleep to be awake. Everything is much deeper. It is like a ball with two inseparable halves.
–Apparently frogs don’t sleep …
-We do not know very well from the phylogenetic point of view what would be the origin of the dream. But we do know that dolphins perform sleep function separately in their brain hemispheres. Other animals, for example, sleep standing up, and we must sleep stretched out. And there is a type of frog that does not sleep.
–Does the orientation of the bed have any basis to sleep well?
-There is no scientific criterion to support it. It’s not that we don’t give it credit, but we don’t support it with the same conviction as the fact that light or noise does harm sleep. As the science of sleep is very new, there is room for many unproven theories. People who sleep badly are addicted to reading about their problem, buying sleeping gadgets, those alpha wave gadgets, pads … All this is nonsense. But people who sleep badly suffer a lot and there is an industry around sleep because we do not yet know many aspects.
–What scientific frontiers remain to be reached in the field of sleep?
-Many. For example, we still do not know what the different phases of sleep are for, what happens if we suppress them … In fact it is logical that we do not know anything about these things because sleep medicine has started not more than 50 years ago, and in I change the medicine of wakefulness … Later, the mechanism of production of some specific diseases is completely unknown, for example that of insomnia. Although we know the causes, we do not know the mechanisms of its operation.
–What pathologies are treated in a sleep unit?
-Basically there are three large groups: insomnia, hypersomnia or excessive sleepiness during the day and parasomnias, which alter the sleep of others: sleepwalkers, children who do not sleep …
–How many sleep units are there in Spain?
– More and more, there are them in almost all hospitals. But there are very few that treat all sleep problems, because there has been a bit of diversification: some treat only the problem of apnea, but if you send them a child or an insomniac they don’t know what to do with it.
–Are daydreams or daydreams a matter of dream science?
-We do not enter into the interpretation, but into why one dreams, why do some remember dreams more, etc. It seems that those who wake up more remember more, and that is why older people remember them more. A certain degree of wakefulness is essential to remember.
Gonzalo casino
This interview was published in September 1999, in number 220 of VERY Interesting.
