Memory problems, heart risk, weight gain: the war routine's effects on our body
In addition to fatigue and increased hunger, living with constant sleep deprivation and stress has other effects, some long-term. Experts explain the risks – and how to limit the damage, or at least some of it
Haaretz
75
9 min read
0 views
In addition to fatigue and increased hunger, living with constant sleep deprivation and stress has other effects, some long-term. Experts explain the risks – and how to limit the damage, or at least some of it
By now, this has become a daily challenge: how many hours of sleep can one get in a night riddled with air-raid alerts, racing to shelter and attempts at shuteye before being woken up again. And not just how many hours in total, but also how long one can sleep uninterrupted. All this comes before the real challenge – staying awake during the day, functioning as normally as possible and perhaps even forgetting – until the next siren – that this is an open-ended state of emergency.
This reality has direct and indirect health implications, some immediate and clearly felt in the ability to function and in planning and concentration. In the longer run, this stressful reality, marked by constant alertness and sleep deprivation, could have a cumulative effect on other bodily systems, including the immune and cardiovascular systems, as well as mental health.
"The professional term for what has been happening now is 'sleep deprivation' due to air-raid alerts," says Prof. Yaron Dagan. "This deprivation harms two main things: one is cognitive – that is to say, everything related to thinking, perception, problem-solving, concentration and memory; the other is emotional – people are gloomier, less patient, and generally in a worse mood, which sometimes results in reckless decision-making."
Dagan, director of the Institute for Sleep Medicine at Assuta Medical Centers, explains that healthy sleep is crucial for waking life, particularly for our cognitive system, "which reboots brain memory in order to clear it for the next 24 hours. This activity takes place in several areas in the brain, and without uninterrupted or adequate sleep – the processes served by sleep are impaired." One stage of sleep, he emphasizes, is crucial for emotional processing, learning and memory formation. "This stage occurs in 90-minute cycles, and with sleep deprivation it's disrupted, affecting our thinking and behavior when awake."
We recommend a 'combat nap' – a 30-45-minute nap to replenish your batteries. It cannot fully replace nighttime sleep, but it certainly helps you feel refreshed.
Prof. Yaron Dagan
Residents in a shelter this week.Prof. Yaron DaganItai Ron
Is there anything that can be done, considering that it is entirely unclear how long this routine will continue? Perhaps a nap here and there? "In principle, sleep is not a bank – you cannot not sleep for a week and then fill the deficit by sleeping for a week," says Dagan. "What we recommend is what's called a 'combat nap' – a planned 30-45-minute nap to replenish your batteries. Even if someone can't doze off, simply lying down, closing one's eyes and relaxing is enough. This is the best way to deal with this sleep deprivation. It cannot fully replace nighttime sleep, but it certainly helps you feel refreshed."
Proper or healthy sleep is not just a matter of quantity; uninterrupted sleep is just as important as getting enough hours. "Sleep that is too short or interrupted – both have the same effects and cause the same harm as sleep deprivation," explains Prof. Giora Pillar, head of the sleep clinic in Clalit Health Services' Haifa District and sleep researcher at the Technion's Faculty of Medicine. "There have been studies on this. In one, students were allowed to sleep for eight hours, but their sleep was interrupted. The damage was found to be the same."
A vicious cycle
The immediate effects are not limited to fatigue and exhaustion. Along with sleep deprivation, unending stress is not only mental but also physiological, affecting many bodily systems. When a person remains alert for an extended period, high levels of stress hormones such as cortisol and adrenaline are secreted. Chronic exposure to these hormones can harm the immune system, increase inflammation and blood pressure and impair cardiovascular function. In addition, stress has been linked to sleep disorders (creating a vicious cycle) and to the worsening of chronic diseases such as asthma and diabetes, as well as to an increased risk of heart disease. Over time, this condition may erode physiological systems and cause an overall deterioration in health.
Over the past two and a half years, with one operation following another and one air-raid siren after another, stress has become a familiar term. In general, it refers to a physical and emotional reaction to threatening or dangerous situations – not just wartime or physical danger, but also everyday pressures such as work overload, mental overload or difficulties in other aspects of life. In today's reality, however, it's almost impossible to isolate stress from sleep deprivation. "Stress is a mediating factor," says Prof. Pillar. "It causes sleeplessness in itself, as well as many other complications."
In many respects, the symptoms of stress and sleep deprivation overlap or reinforce one another. In part, this connection is evident in eating patterns. Like stress, sleep deprivation is a risk factor. When sleep is reduced, levels of ghrelin (the hunger hormone) soar, while levels of leptin (the satiety hormone) fall. The result is increased hunger, especially for high-calorie, sugary and fatty foods. A 2004 study released by researchers from the University of Chicago demonstrated this clearly. The researchers hypothesized, based on their findings, that the body interprets sleep deprivation as a state of energy deficit – even if that's not exactly the case.
Medical interns who sometimes work two 26-hour shifts a week don't develop long-term complications. That is to say, it's reversible – up to a point.
Prof. Giora Pillar
Prof. Giora PillarThe underground ward at the Tel Aviv Sourasky Medical Center, two and a half weeks ago.Tomer Appelbaum
Chronic overeating under such conditions can lead to weight gain, increased insulin resistance and a higher risk for type 2 diabetes, cardiovascular disease and other metabolic disorders. In addition, ongoing caloric excess, driven by fatigue, also hinders the body's ability to regulate metabolism and balance energy.
And the list of risks does not end there. According to Pillar, sleep deprivation also affects the immune system. "Sleepless patients or patients who sleep poorly, that is to say: people who suffer from chronic sleep disorders, are already suffering from irreversible complications," he warns. "We will see higher rates of high blood pressure, more cases of metabolic syndromes, more diabetes, more obesity, more strokes and more cancer."
To a certain extent, these symptoms are reversible, as reality has proven. "Soldiers who sleep too little and then sleep through the weekend are not at risk in the long term," Pillar illustrates. "Medical interns who sometimes work two 26-hour shifts a week make up for lost sleep and don't develop long-term complications. That is to say, it's reversible – up to a point."
However, given the current reality, which has already lasted more than a week and even a fortnight, the question becomes where the line lies beyond which the damage becomes irreversible, or only partly reversible. This is a crucial question. "We are already seeing patients whose diabetes is no longer balanced," he says, "or who have high blood pressure."
A 2016 study published in the International Journal of Cardiology found a clear link between sleep duration and coronary heart disease. The findings indicate that people who sleep seven to eight hours per night are at low risk, with every one-hour reduction associated with an 11 percent increase in the risk of heart disease. These findings were reaffirmed last November in another study, published in BMC Cardiovascular Disorders, which indicated that people who sleep six hours or less are at almost twice the risk of dying from kidney or heart disease compared with those who sleep longer.
An immune system out of balance
Over the past two decades, many studies have examined the link between sleep quality and immune system function. Among other findings, people who sleep less than six hours a night produce fewer antibodies after vaccination; on the morning after a sleepless night, a significant increase is seen in the production of inflammatory cytokines – proteins secreted by immune cells in response to infection or injury; and, in general, proper sleep strengthens anti-inflammatory and anti-viral reactions, while inflammatory signals from the immune system affect the structure and depth of sleep.
Prolonged stress and sleep deprivation may cause a slightly higher risk of certain infections, mainly respiratory – and the recovery process may also be slower.
Prof. Cyrille Cohen
Prof. Cyrille CohenA light rail station in Tel Aviv last week.Tomer Appelbaum and Itai Ron
According to a 2019 study published in Nature Reviews Immunology, sleep deprivation increases activity in the sympathetic nervous system (responsible for the body's response in situations of threat and danger), which in turn raises stress hormone levels and releases inflammatory cytokines. It was found that in chronic sleep disorders, the overall level of inflammation in the body increases, while antiviral responses grow weaker.
"Sleep deprivation is documented as one of the main biological factors affecting the immune system (when not diseased)," says Prof. Cyrille Cohen, head of the laboratory of immunology and immunotherapy and dean of Bar-Ilan University's Faculty of Life Sciences. "In principle, conditions such as stress and sleep deprivation do not weaken every component in the immune system but rather cause an imbalance in its function." He says this may manifest in several ways. "For instance, you're at a slightly higher risk of certain infections, mainly respiratory – and the recovery process may also be slower." However, Cohen emphasizes that "the effect is usually mild, and varies greatly from person to person."
