Brain chemicals may be key in eating disorders

This is an automatically translated article.

1. What is an eating disorder?

Eating disorder is one of the diseases belonging to the group of psychological origin, manifested by 2 main groups: binge eating or anorexia without being based on the current needs of the body. These disorders take a huge toll on physical and mental health.
People with the disease experience huge disturbances in eating behavior as well as thoughts and feelings related to the daily need to eat. Anorexia nervosa is the most common disorder reported in this group of eating-related mental illnesses. Meanwhile, binge eating is a chronic condition that occurs when a person eats an excessive amount of food in a short period of time and loses control over stopping eating. Binge eating can affect physical disorders such as obesity, diabetes, high blood pressure and heart disease.

2. What is anorexia nervosa?

Anorexia nervosa is a physical and emotional eating disorder that includes:
Severely limited food intake Distorted body image Refusal to maintain normal body weight Fear of weight gain despite being very underweight Prolonged or severe anorexia can lead to serious health problems. It can even cause death. The cause of anorexia is unknown, which is reversible with proper treatment. Both men and women can develop anorexia or other eating disorders.
Women with anorexia may have infrequent or no menstrual periods. They may not have a normal menstrual cycle until they regain a healthy weight. According to the National Institute of Mental Health (NIMH) website, an estimated 0.5% to 3.7% of women experience anorexia at some point in their lives. The NIMH does not provide data on men with anorexia.
Researcher Walter Kaye, MD, says: “When sick, people with anorexia do not seek or respond to the kinds of comforts and pleasures that most of us enjoy, including food, ” says researcher Walter Kaye, MD.
They also resist and ignore feedback indicating their precarious health. They did not see a gaunt figure in the mirror. They ignore the most obvious warning signs and dismiss comments from loved ones claiming they are seriously ill medically.
People with anorexia nervosa always deny themselves, not only food, but often the many comforts and pleasures in life, but can be very active and productive.
Chứng biếng ăn kéo dài hoặc trầm trọng có thể dẫn đến các vấn đề sức khỏe nghiêm trọng.

3. Brain Chemicals Affect Eating Disorders

3.1. Decreased Dopamine May Affect Eating Disorders

Researchers from the University of Pittsburgh reported that recovering anorexic showed increased dopamine in the brain. Dopamine is a chemoattractant involved in weight, feeding, reinforcement, and reward behavior. Researchers are now reporting that women who have recovered from an eating disorder show abnormal serotonin levels.
Changes in the dopamine system may help explain the dysphoric symptoms of anorexia. The researchers took that approach because malnutrition alters brain chemistry. Patients with previous anorexia nervosa must have been recovering from an eating disorder for at least 1 year prior to the study. They were maintaining a healthy weight and having regular periods. The women also did not take psychoactive drugs (such as antidepressants) or abuse alcohol or drugs for at least 3 months prior to the study.
When researchers took CT-scans of the brains of previously obese people, they found the opposite pattern. Kaye and colleagues write that obesity is associated with reduced activity in the brain's dopamine reward centers. The findings support the possibility that dopamine binding may be inversely related to weight and anorexia at one end, and obesity at the other end of the spectrum.
Both chemicals are strongly associated with appetite, mood and impulse control, all of which are altered in people with eating disorders such as anorexia and bulimia.
Longtime anorexia researcher Walter H. Kaye, MD, says: “Both of these [chemicals] are very important regulators of how people respond to stimuli. "It makes sense that we find disturbances in both."
Những thay đổi trong hệ thống dopamine có thể giúp giải thích các triệu chứng của chứng biếng ăn.

3.2. Serotonin and eating disorders

People with severe obsessive-compulsive disorder, depression, and binge eating were all found to have significantly low serotonin levels. Neurotransmitters such as serotonin and dopamine are secreted in the digestive system (intestines) and central nervous system during eating. This is an important basis for the relationship between eating disorder behavior and mental disorders. A study in London - England showed that people with anorexia nervosa had high levels of serotonin (who had a state of vomiting) and at the same time researchers also found a large change in serotonin receptors. . These chemicals and hormones are involved in the hypothalamus. This damage to the hypothalamus can lead to abnormalities related to dietary regulation, in addition to possible symptoms of temperature regulation, sexual behavior, and locomotion.

3.3 Other chemicals and eating disorders

The researchers also found that cholecystokinin, a hormone that causes satiety and reduces appetite, was unusually low in people with bulimia. Low levels of this hormone cause a loss of satiety and the patient may experience symptoms of uncontrolled eating.
Other studies have also shown that the cause of binge eating is related to neuromodulatory peptides such as neuropeptide Y and peptide YY. Both of these substances work to induce hunger and cravings, and this effect is combined with another peptide called leptin. When leptin is released with fat cells, it causes an appetite effect in normal people. For people with vomiting, the amount of peptides is reduced, others have normal levels of peptides, but they are obstructed by the blood-brain barrier causing insufficient amounts to suppress appetite.
Cortisol is also a hormone involved in eating disorders. Cortisol is secreted in the adrenal cortex to increase blood sugar and metabolism. In people with eating disorders with relatively high concentrations, this imbalance can be caused by problems in and around the hypothalamus.
Nồng độ hormone cholecystokinin thấp là nguyên nhân gây nên những triệu chứng ăn uống không kiểm soát.

4. Genes and environment influence eating disorder behavior

McGill University professor of psychiatry Howard Steiger has also studied serotonin levels in women with eating disorders, although his research has mainly focused on people with bulimia. Evidence suggests that both genetic susceptibility and extrinsic factors such as childhood abuse or trauma can contribute to eating disorders.
Some people may be genetically predisposed to eating disorders. Others may be genetically less likely to develop an eating disorder for other reasons.
Although some patients with anorexia respond well to widely used treatments, including behavioral therapy and selective serotonin reuptake inhibitors (SSRIs) such as Paxil and Zoloft, these other people don't.
The team plans to study eating disorders in particularly vulnerable families in an effort to better understand genetic susceptibility. The study was supported by the National Institutes of Health and will involve about 400 families with two or more members with an eating disorder.
Many people seem to have some kind of genetic susceptibility, but that doesn't mean they will develop an eating disorder. But it's possible that women who inherit this vulnerability have to be especially careful about their diets, which could trigger an eating disorder.
Researchers recently compared brain images of healthy women with those of anorexic in the past. The images show that the previously anorexic patients had increased activity in brain regions that produce dopamine. Dopamine is a chemoattractant involved in weight, feeding, reinforcement, and reward behavior.
This finding could help explain why people with anorexia nervosa are able to lose weight, resist overeating, exercise, and be protected from substance abuse, the researchers wrote. liking and insensitive to conventional rewards".

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Reference source:
Patients Stories