“Lark people” were more susceptible to anorexia nervosa

A new study by researchers at Massachusetts General Hospital, University College London and the University of the Republic in Uruguay found that people with anorexia nervosa, an eating disorder, are more likely to wake up early. “Our results indicate that anorexia nervosa is a morning disorder, unlike most other evening-related mental illnesses, and confirm the association between anorexia nervosa and insomnia that was observed in earlier studies,” said Associate Professor of Anesthesia from Harvard Medical School and one of the study authors, Dr. Hassan Dashti.

Scientists have long tried to study the connection between eating disorders and the body’s internal clock, known as circadian rhythms, which regulate various biological functions, including body temperature cycles and sleep-wake patterns. The current study’s authors expanded their search by examining genes associated with anorexia nervosa, the circadian clock, and sleep patterns such as insomnia. They used a statistical method called Mendelian randomization, which analyzes how genes associated with one trait can influence others. For example, by studying the sleep patterns of people with genetic differences associated with anorexia nervosa, researchers have gained insight into the relationship between the disorder and sleep.

The study found a bidirectional association between genes associated with anorexia nervosa and genes associated with early rise. They concluded that waking up early may increase the risk of developing anorexia nervosa, and having anorexia nervosa may lead to waking up earlier.

By the way, the bidirectional connection between circadian rhythms and mental disorders has been known for a long time. For example, a tendency to be an evening chronotype (meaning night owls) is associated with depression and schizophrenia. Conversely, bipolar disorder, anxiety, and the onset of schizophrenia lead to changes in the rhythmicity of master clock genes. There is also some evidence for the involvement of the circadian system in eating disorders, primarily focusing on the association between binge eating disorder and evening chronotype in association with other psychiatric disorders. However, the importance of the circadian system in anorexia nervosa was until now unknown.

In addition, scientists were able to establish a connection between anorexia nervosa and an increased risk of insomnia. The authors believe that their discovery will help in the search for circadian therapy for the prevention and treatment of anorexia nervosa. Treatment for this eating disorder is still challenging, and existing treatments often result in people relapsing into the disease. The relapse rate reaches 52 percent. Treatment of anorexia takes at least 5 years. This process is very difficult, and much depends on the patient and his desire to overcome the disease. Not only medications (mainly antidepressants), but also special psychological correction play a big role. Only about 60% of patients, after undergoing treatment, return to a healthy lifestyle. 20% have to be treated for life, and another 20% die.

In addition, doctors do not fully understand what causes anorexia nervosa. “Our findings suggest the role of morning work schedule as an underappreciated risk factor for anorexia nervosa, the significance of which should be further explored in the context of other established risk factors. If this risk factor is found to be significant, measures to promote later work schedules may be considered. Our results also suggest the need to investigate circadian mechanisms for future treatment of anorexia nervosa. Evening bright light therapy recommended for patients with early morning awakening insomnia may be effective in the prevention and treatment of anorexia nervosa,” the study authors noted.

And yet, somnologist Alexander Melnikov notes that early morning awakenings with the inability to fall asleep again are closely associated with depression and are considered a characteristic sign of depression (although this is not always the case): “That is, among those who were classified as morning type people, a significant part could consists of people with depressive disorders, and there is an association of anorexia nervosa specifically with depression, and not with the characteristics of the circadian rhythm. In addition, it is known that the morning and evening type of behavior strongly depends on social factors – not only genetic ones. Now, if exactly the genotype features that predispose to the morning type were recorded (they are known), the results would be more interesting.”

The word “anorexia” came into our dictionary from Ancient Greece, it means “lack of the urge to eat.” Anorexia nervosa was first described in the 17th century by Dr. Richard Morton. He briefly described his patient as “a skeleton covered with skin” and wrote that “in the eighteenth year of her life, in the month of July, she fell into complete depression from the many worries and passions in her mind … her appetite began to decline, and her digestion became bad, her flesh has become limp and loose, and she looks pale.” However, this disease was not widespread for centuries. Beauty standards were completely different – ladies with a body were considered beautiful, while thinness was associated with ill health.

But at the end of the 20th century, beauty standards changed dramatically. The world has been captured by the fashion for disembodied nymphs, the parameters of which are possessed by an absolute minority. However, purely physically, only 5 percent of women worldwide fall within the parameters of 90–60–90. By the way, the parameters themselves are completely fictitious. At one time, such mannequins appeared in France – it was convenient to sew on them. And it was for them that they began to select models. And then – off we go…

Many people, especially young girls, today want to be like models from the catwalks. And they do this in a variety of ways. Teas and diet pills, diets, intense physical activity – this can begin the path not only to greater attractiveness, but also to anorexia.

Anorexia nervosa is a very serious illness and has the second highest mortality rate among mental illnesses. Today, doctors use this term to refer to an eating disorder and mental disorder, which is expressed in increased attention to food and one’s own weight, as well as extremely strict restrictions on food. The main signs of anorexia are the fear of obesity (which turns into an obsession) and dissatisfaction with one’s figure. Anorexics are so afraid of getting fat that they can sometimes literally starve themselves to death.

“Someone simply doesn’t eat, someone eats and then induces vomiting (this already has something in common with bulimia, but with this disorder patients still eat a lot at first, and people with anorexia eat very little), someone tortures yourself with endless exercises to increase energy expenditure,” says biologist Irina Yakutenko. — The prevalence of anorexia in Western societies has remained approximately constant for quite some time: overall, less than 1% of people experience this disorder in their lifetime (women are much more likely than men). But among teenage girls, the incidence of anorexia is rising, and this is not good, since this disease can lead to serious health problems and even death. Although today it is common to blame society for everything (conventional fashion magazines and Hollywood promoting unrealistic beauty standards), this is not the only factor associated with the development of eating disorders (ED). At a minimum, genetics cannot be discounted: anorexia and other eating disorders have a very significant genetic component. Certain psychological characteristics can also increase the risk of developing anorexia, but they are also tied to genetics, which, however, can be enhanced by the environment. And finally, the likelihood of various eating disorders is associated with a person’s circadian rhythms. This remarkable fact was recently discovered for bulimia and binge eating: these disorders are more characteristic of night owls (as well as depression and increased anxiety). But anorexia, as an analysis in a new work has shown, occurs more often in early risers, and even more often in those who have so-called morning insomnia. That is, people who tend to wake up too early, even if they have not yet gained enough hours of sleep.”

As Irina continues, there are several seemingly logical explanations for these patterns: “People with the evening chronotype (“night owls”) are more active in the evenings, and they have more energy and desire at this time. At the same time, if they live according to a universal human schedule, by the evening they accumulate fatigue and (often) negative emotions, and the ability to control impulsive behavior decreases. Therefore, evening and night snacks do not consist of cucumbers and radishes, but of something much more satisfying, which gives positive emotions, but with the help of which it is very easy to go through the necessary caloric intake. The cause-and-effect relationship between anorexia, morning chronotype and morning insomnia is not so obvious. Research shows that those who wake up in the morning without enough sleep have higher cortisol levels than those who sleep until they get enough hours of sleep (although cortisol is higher in the morning for everyone). And perhaps such high cortisol makes people more anxious – including about their own weight. Or maybe the circadian rhythms that determine the morning chronotype influence some other processes, which, in turn, increase the risk of developing anorexia.”

At the same time, the expert reassures: the findings of the study do not at all mean danger for all “early people” without exception: “As I already wrote, this is, in principle, a rather rare disorder, and the connection with the morning chronotype was not too significant. But as one of the risk factors, being an early riser and morning insomnia seem to have a place. Accordingly, switching people with anorexia to a later-wake-up regimen could theoretically help them cope with their problem.”

Scientists remind us that circadian rhythms can influence our lives much more than we might realize. In the modern world, with its artificial light and the concentration of many important activities in the morning, we do not pay much attention to them. “But it probably makes sense to be a little more careful about making sure your life schedule is better aligned with your body clock. This can help you cope more effectively with tasks that, at first glance, have nothing to do with the biology of sleep and wakefulness,” the expert says.