We live in a culture that has the pride of little sleep. The people who sleep nine hours a day are considered lazy, while enjoying of the that in five or six had already jumped off the bed.

Of the five million years that have gone before us, our species lived in a world without electric light, in which the routine of sleep and wakefulness was organized in accordance with the alternation of days and nights.

The clarity that came to the photosensitive cells of the retina at the dawn of the sun, stimulating the brain areas responsible for the control of cell division, the production of hormones and proteins involved in the metabolic reactions necessary to cope with the daily struggle.

On the contrary, the arrival of the night modified the metabolism of the form of synthesizing new proteins and hormones, neurotransmitters, melatonin and other mediators to be more contemplative, with the muscles relaxed and willing to find a corner in the cave for hibernation.

In the evolution, in respect to the natural order, the set of biochemical reactions responsible for the metabolism of animals and plants, fungi and bacteria – are organized in daily cycles with an approximate duration of 24 hours, a feature that, in the decade of 1950, received the name of the circadian rhythm (from Latin circa diem, about a day).

Although circadian cycles are controlled by endogenous mechanisms, independent of the consciousness, the external factors that may interfere with their duration. Among them, the most important is the light of the sun or from artificial sources, especially those that emit in the blue band of the light spectrum.

The human Beings kept in the shadows silent for 28 hours, not resist in the waking state. The interference with the length of the days and the nights that subverts the alternation of exposure to lightness and darkness is the cause of the phenomenon known as jet lag.

Surveys epidemiological made in the last twenty years have evaluated the adverse effects that the deprivation chronic sleep exerts on human health. Some of them raised the suspicion that the sleeping little encurtaria longevity.


In 2010, a study conducted at the Women’s Hospital in Boston, revealed that the young men detained in a regime of sleep deprivation for a week, develop insulin resistance, a condition that leads to the increase of the concentration of glucose in the blood, characteristic of diabetes.

The authors of this study have just to update it in a publication in the journal Science Translational Medicine.

For six weeks, kept 21 participants in one of the suites that the hospital has become a laboratory sleep study. All are maintained in a regime that allowed them to sleep only five, six hours, each 24-hour period. The hours of going to bed changed every day. To interfere with the circadian rhythm, the rooms had no windows and the dark and light cycles were programmed to last for 28 hours instead of 24 as usual.

With the aim of preventing that the circadian rhythm is reajustasse for its own account, the lighting was maintained at levels equivalent to those of the sunset. Has not been allowed access to TELEVISION, radio or the internet.

The blood samples collected at fasting was charged to lower concentrations of insulin, associated to the increasing rates of glucose, in all participants. In three of them, the glucose in blood came to the strip that goes from 100 a120, called pre-diabetes.

The energy expended at rest (which quantifies the amount of calories consumed by the body still) fell by an average of 8%. If this level of energy consumption most economical was maintained for a year, would result in an increase in body weight – como perder peso rapido – of almost six kilograms.

After a ten-day period of recovery, in which the participants remained in the laboratory, however keep in dark and light cycles with a duration of 24 hours, but slept ten hours during the night, the secretion of insulin and the sugar levels in the circulation returned to normal values.

For those that the job requires them to spend months or years in cycles of day and night irregular, these changes would also be reversible?

Can you, the reader, to sleep and to wake up every day at the same time? I don’t.

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