Reaction times are as bad as when under the influence of alcohol
We all know the feeling: after a short night, we're tired and less focused. If this lack of sleep extends over a longer period, it has measurable consequences for the body.
A sleep deficit has a similar effect on our reaction times as alcohol. After 24 hours without sleep, participants in a study displayed, on average, similar reactions to people with a blood alcohol level of one part per thousand . There are however exceptions: some people are less sensitive to little sleep and their abilities are hardly affected.
Insufficient sleep leads to greater risk-taking
Those who suffer from a sleep deficit make riskier decisions, according to a study by the University Hospital of Zurich. What’s interesting here is that the participants in the study didn't rate themselves as higher risk-takers. This means that we often don't necessarily notice ourselves how much our lack of sleep affects us.
In addition to reaction times and decision-making behaviour, insufficient sleep also affects the mind in other ways: memory skills decrease, and we quickly become irritable and unfocused. Depression is also closely linked to lack of sleep. In other words, a sleep deficit can trigger depressive moods. In turn, sufferers of depression often sleep poorly – a vicious cycle.
Insufficient sleep affects gene activity
What many people don't know is that our genes work our whole life long. The body depends on gene activity, known as gene expression, as it performs functions such as cell regeneration, for example. Sleep also affects gene expression, according to a group of researchers at the University of Surrey.
When participants in a study slept barely six hours for a week, their gene expression was disturbed. This disturbance affects the hormones that are released on a 24-hour basis, thereby bringing the human body's «inner clock» into disarray. It is assumed that this inhibits cells throughout the body from regenerating properly, weakens the immune system and makes it harder for the body to compensate for stress.
Schlafmangel erhöht den Blutzucker
A lack of sleep affects glucose tolerance – a fact proven by several studies. According to these studies, people who sleep less than six hours have higher blood sugar levels. After one week of insufficient sleep, some study participants already had a metabolic condition similar to that of a diabetic.
It can be seen that getting too little sleep has a whole range of consequences that are directly associated with the sleep deficit. The consequences of insufficient sleep also lead to long-term illnesses. When a group of researchers from the US put together the results of a number of studies, one conclusion was that a chronic sleep deficit increases the risk of diabetes mellitus and cardiovascular diseases. Large-scale studies like this clearly show that people who sleep too little are more likely to die earlier. However, the problem with such studies is that there is also a section of the population that are less sensitive to insufficient sleep. The studies therefore merely show a tendency, but cannot speak for the individual.
Varies from person to person
The study at the University of Pennsylvania confirms what many experts say: people react very differently to insufficient sleep. While some displayed only minimal cognitive deficits in their attention levels, a third of those studied reacted extremely sensitively and could hardly concentrate. According to Serge Brand, psychologist and sleep researcher at UPK Basel, «the decisive factor is not so much the duration of sleep, but the subjectively perceived quality of sleep».