Bulimia on the Brain

As a long time sufferer of bulimia nervosa, an eating disorder characterized by episodes of bingeing on food followed by purging either through the use of self-induced vomiting or by the abuse of laxatives and/ or exercise, often including episodes of self-starvation, I have struggled with the negative stereotypes that insist on eating disorders as being the result of vanity, the desire to be thin, a characteristic highly promoted in our culture as a key element to feminine beauty and attractiveness (2). While social and environmental factors cannot be discarded as playing a crucial role in the development and perpetuation of eating disorders, resulting in abnormal and often extremely dangerous extremes as an attempt to control weight, we must take into consideration the other factors, such as abnormal brain chemistry and genetics, that are now shown to influence and even predispose the development and persistence of eating disorders in certain individuals.

While I do not deny the influence of media and culture on eating disorders, my own personal experience has led me to strongly believe that eating disorders such as bulimia nervosa have much less to do with body image, but rather something deep-rooted in the self, in the psychological make-up of the sufferer, something that drives the individual to pursue unhealthy, self-medicating coping skills as an attempt to ease whatever coexisting psychological illness, such as depression, anxiety, suicidal tendencies, a history of drug and/or alcohol abuse and/or obsessive-compulsive disorder. Bulimia is estimated to effect 3% of women in the United States, most of whom experience the onset of the disease during adolescence (1). While it is clear that all women are exposed to the cultural pressure to be thin and beautiful, only a very small percentage of women develop eating disorders, suggesting that there is something quite different about the psychological make-up of those who develop the diseases of bulimia or anorexia nervosa, the most deadly psychological illness characterized by self-starvation and extremely restricted food intake (5).

Research conducted in the United States and Great Britain now suggests that chemical alterations of the brain may be a largely contributing factor in those who suffer from bulimia, particularly concerning the neurotransmitter serotonin (1). Serotonin is a neurotransmitter that acts as a messenger carrying out communication in the brain and the body. The neurotransmitter travels from one neuron along serotonergic pathways and then bind to another at a specific area of the neuron called the receptor site, and in fact disturbances in these pathways and the ability of the serotonin to bind with its corresponding receptors are shown to correlate with the presence of eating disorders (2). Serotonin is a neurotransmitter that helps regulate mood is associated with many behaviors such as hunger, sleep, sexual response, impulse control, anger, aggressive behavior, anxiety, depression and perception. Abnormally low levels of serotonin correspond with increased hunger and inability to produce satiety, extreme depression, suicidal tendencies and aggression. Inversely, abnormally high levels of serotonin foster a constant state of acute anxiety (often characterized by the body's reaction to be in continual fight or flight mode), obsession with perfectionism, a constant state of feeling overwhelmed and insomnia (3). Other abnormalities concerning serotonin that exist in sufferers of bulimia include the persistence of the chemical alterations, including the reduction in the ability of serotonin to bind to receptors in certain brain regions following recovery from the eating disorder, as well as the continual presence of mood disorders, suggesting that coexisting psychological conditions such as depression are not a result of the bulimia, but rather a coexisting condition related to serotonin levels (1). Additionally, bulimic patients do not experience the normal decline of serotonin binding that occurs with aging (4).

Low levels of serotonin that contribute to the sense of depression are theorized to be increased during bulimic episodes of bingeing that enhance the sufferer's feeling of peace and well- being. In particular, bingeing on carbohydrates, starches and sweets are thought to increase levels of serotonin. On the other hand, the exact opposite is true for anorexics. When too much anxiety producing serotonin is present, reducing caloric intake to starvation level lowers the amount of serotonin, producing calmness and a sense of regaining control (3). This concept demonstrates that individuals with abnormal levels of serotonin may be subconsciously driven to eat, over- eat, or not eat at all as an attempt to increase the feeling of emotional well- being. While it is shown that irregularities in serotonin may predispose and increase vulnerability to the development of eating disorders such as bulimia, and that these irregularities persist even after recovery (5), it is also important to recognize that the act of starvation and purging may disrupt serotonin levels, increasing depression and anxiety, which are often considered side- effects of eating disorders as a result of vitamin deficiencies and malnutrition (3).

Indeed, there are individuals with elevated or reduced amounts of serotonin that do not develop eating disorders as well as the presence of eating disordered people that do not have a pre-existing condition of serotonin associated abnormalities, further suggesting the presence of other contributing factors (3). Genetics are now thought to play an important role in the presence of eating disorders, such as genetic predisposition to serotonin abnormalities that can run in families (4). It is thought that a high percentage of eating disorder patients have parents with some kind of undiagnosed anxiety or compulsive behavior disorder (3), while research conducted by Dr. Walter Kaye of the University of Pittsburgh who set up an international study to see if eating disorders run in the family showed that 10% of his anorexic and bulimic patients also had a relative with an eating disorder (5).

Genetic studies with relation to eating disorders have also been conducted at the Maudsley Hospital in London, focusing mainly on the serotonin system. The study involved examining the whole human genome as an attempt to find the genes that may cause anorexia, and because of the known effect of serotonin on appetite and eating, the research team investigated the 5HT2A serotonin receptor which has been shown to be involved in the regulation in feeding, and drugs that block this receptor cause weight gain. Variations in this gene for serotonin receptors were found in anorexic patients, and in fact the anorexic women were shown to be twice as likely to have the variant gene than women without eating disorders (5). Another discovery that demonstrates the potential of genetics to influence eating disorders is the debunking of the stereotype that eating disorders only exist in Western countries, those influenced by the culture of thinness.

Even in cultures that embrace big women as being beautiful, anorexia has been known to exist. Dr. Hans Hook conducted research in the Caribbean island of Curaçao, one such culture where fat is considered attractive. His investigation found that out of 144, 000 cases that were examined for the presence of eating disorders, 291 cases were scrutinized in detail and he was able to definitively confirm eight cases of anorexia nervosa that existed in this small population. The ratio of incidence of anorexia in Curaçao was equal to that of Europe, indicating that eating disorders exist in a cross- section cultures in proportionate amounts, regardless of societal influences (5).

These investigations and studies that prove the chemical and genetic components to eating disorders such as bulimia are great strides towards the understanding and acceptance of eating disorders as a psychological disease, devaluing and disproving many of the wide-spread associated pejorative views of eating disorders as being an obsession with perfection and thinness. As long as society continues to be open- minded about the causes and reasons behind the stigmatized conditions of bulimia and anorexia, hopefully more sufferers will come forward to seek help and treatment, leaving behind the shame of their disorder. I have accepted that there are many contributing factors that contribute to my condition of bulimia, and although I am in recovery and have successfully sought treatment, which I encourage other sufferers to do, I am relieved to know that this disease is not my fault, rather a complex combination of cultural influences, but more importantly those of genetics and brain chemistry.

Sources:
1. "Brain Chemicals May Cause Bulimia," a BBC health news article, (http://news.bbc.co.uk/2/hi/health/192727.stm)
2. "Biochemical Correlates of Anorexia and Bulimia," a 1999 Serendip web paper, (/bb/neuro/neuro99/web1/Hellew.html)
3. "Genetics and Biology, " an article from a very resourceful website dedicated to eating disorders, (http://www.something-fishy.org/isf/genetics.php)
4. "Alterations in Brain Activity Linked to Bulimia, " an informative article from an organization promoting mental health, (http://www.4therapy.com/consumer/conditions/article/6907/75/Alterations+in+Brain+Activity+Linked+to+Bulimia)
5. "Genetic Clues to Eating Disorders, " a great BBC health news article, (http://news.bbc.co.uk/2/hi/health/259226.stm)