People whose circadian rhythm is altered are more likely to develop an addiction  —such as alcohol, drugs, or foods rich in carbohydrates— according to studies carried out by Carolina Escobar and colleagues in the Department of Anatomy of the Faculty of Medicine (FM) of the National Autonomous University of Mexico.

Circadian rhythm is any biological process (physical, mental, and behavioral) that displays an endogenous, entrainable oscillation of about 24 hours, cycle that respond primarily to light and darkness in the environment.

Some behaviors in the modern life, such as not sleeping the necessary hours, or eating not only during the day, but also at night, potentiate its alteration. During the day our body is in active mode: the heart beats stronger, the breath is more intense, the digestive system works normally because it has food, and at night it changes to a way of rest: we sleep and release hormones that help us repair tissues and eliminate metabolic wastes, among other functions.

In other words, explained Escobar, no organ acts evenly during the 24 hours cycle; there are moments when it will be very active and moment when it won’t. These are the circadian rhythms.

For the proper functioning of our body, all organs, with their respective functions, must be coordinated in an active mode or in a rest mode. If this is disorganized, people may want to rest at day and be active at night. This disorganization causes that repair function at night is not performed correctly and, our performance throughout the day will not be efficient, and if this persists we can deteriorate and ill,  lose control over our responses to the social environment and develop an addiction, she said.

Because of this alteration of circadian rhythms, large sectors of modern society have chronic fatigue, show irritability, suffer from depression and develop obesity; it is even believed that the appearance of some cancerous tumors could be due to the lack of night repair.

We have worked with young rats. We do not let them sleep, we unveil them and we force them to be active. In this way we could see that during the sleeplessness they start to eat, especially foods rich in carbohydrates, which made them fat and they acquired metabolic syndrome, which predisposes to develop diabetes, gout and cardiovascular diseases,” Escobar said.

With this model we mimic a little what happens with the young human population and what are the consequences of the constant alteration of the circadian rhythms. This work is already finished and is subject to evaluation for publication,” she said.

In relation to this subject, there are two types of people: the morning ones, those that easily get up early and begin their activities; and nocturnal, they have difficulty getting up early, but may be active late into the night.

In the group of nocturnal people has been recorded a greater propensity to develop metabolic diseases and to consume alcohol and drugs; possibly by the mismatch of their circadian rhythms with the light-dark cycle,” Escobar said.

Circadian rhythm is also important in the areas of the brain that control impulses. “If the individual is tired because he has not slept enough, or if his circadian rhythms in the brain areas that regulate impulse control are not well synchronized, he will lose control, become weaker stimuli response, and may fall easily into impulsive behaviors, including addictions.”

Many young students are exposed to desynchronize sleeping-awaking schedules. “This represents a red flag that needs attention, because it could be a factor that facilitates the approach to alcohol and drugs as a strategy to reduce the anxiety and irritability coming from all this loss of their rest control,” concluded UNAM researcher.