Biological & Physiological aspects of eating disorders
Introduction
Eating disorders are complex mental health conditions that manifest in unhealthy eating habits and a distorted body image. They are serious and often fatal illnesses that are associated with severe disturbances in people’s eating behaviours and related thoughts and emotions. While societal pressures and psychological factors play a significant role in the development of eating disorders, biological and physiological aspects also contribute significantly to these conditions. This blog aims to delve into the biological and physiological underpinnings of eating disorders to foster a deeper understanding of these serious conditions.
The Biological Factors:
1. Genetic Predisposition:
Research has demonstrated a genetic link in eating disorders, indicating that these conditions can run in families. Twin studies reveal a higher concordance rate for anorexia nervosa and bulimia nervosa among identical twins compared to fraternal twins, suggesting the role of hereditary components. Specific genes related to the regulation of eating behaviours, stress response, and serotonin pathways have been implicated, though the genetic picture is complex and multifactorial.
2. Neurobiological Abnormalities:
Neurotransmitters such as serotonin, dopamine, and norepinephrine are involved in the regulation of mood, appetite, and satiety. Imbalances or disruptions in these neurotransmitter systems are often observed in individuals with eating disorders. For example, alterations in serotonin levels have been associated with obsessive-compulsive behaviours, rigidity, and mood disturbances, which are common in anorexia nervosa.
3. Brain Structure and Function:
Advances in neuroimaging have allowed researchers to study brain structure and function in people with eating disorders. Findings suggest that there are differences in the size and activity of certain brain regions that are involved in reward processing, decision-making, and emotional regulation, such as the prefrontal cortex, amygdala, and striatum. These alterations may contribute to the persistence of disordered eating behaviours.
The Physiological Factors:
1. Starvation and the Body’s Response:
The act of starving, which is common in anorexia nervosa, triggers a myriad of physiological responses. The body shifts into a state of conservation, slowing down metabolism and
decreasing energy expenditure to preserve vital functions. This can lead to hormonal imbalances, including reduced levels of reproductive and thyroid hormones, which can have extensive effects on the body, including loss of menstrual cycles in women, reduced bone density, and slowed growth.
2. Binge Eating and Purging Cycles:
Bulimia nervosa and binge eating disorder involve episodes of consuming large amounts of food followed by feelings of shame or guilt. In bulimia nervosa, this is often followed by compensatory behaviours such as self-induced vomiting, excessive exercise, or misuse of laxatives. These behaviours can lead to electrolyte imbalances, dehydration, gastrointestinal problems, and cardiac issues, which are severe physiological consequences that can exacerbate disordered eating patterns.
3. The Gut-Brain Axis:
Emerging research suggests that the gut-brain axis, which involves bidirectional communication between the gastrointestinal tract and the central nervous system, may play a role in eating disorders. Gut microbiota has been found to influence mood and behaviour, and changes in gut bacteria composition have been observed in individuals with anorexia nervosa. This suggests that the microbiome may be a contributing factor to the development and maintenance of eating disorders.
Mental and behavioural signs may include :
Dramatic weight loss
Concern about eating in public
Preoccupation with weight, food, calories, fat grams, or dieting
Complaints of constipation , cold intolerance, abdominal pain, lethargy, or excess energy
Excuses to avoid mealtime
Intense fear of weight gain or being “fat”
Dressing in layers to hide weight loss or stay warm
Severely limiting and restricting the amount and types of food consumed
Refusing to eat certain foods
Denying feeling hungry
Expressing a need to “burn off” calories
Repeatedly weighing oneself
Patterns of binge eating and purging
Developing rituals around food
Excessively exercising
Cooking meals for others without eating
Missing menstrual cycle (in people who would typically menstruate)
Physical signs may include :
Stomach cramps and other gastrointestinal symptoms
Difficulty concentrating
A typical lab test results (Anaemia , Hypothyroid , imabalanced hormones, low potassium, low blood cell counts, slow heart rate)
Dizziness
Fainting
Feeling cold all the time
Sleep irregularities
Menstrual irregularities
Calluses across the tops of the finger joints (a sign of inducing vomiting)
Dry skin
Dry & thin nails
Thinning hair
Muscle weakness
Poor wound healing
Poor immune system function
Conclusion:
Eating disorders are not simply a result of a desire to be thin or a consequence of poor self- control; they are serious conditions with deep-rooted biological and physiological factors. Understanding these aspects is critical for developing more effective treatments and support systems for those affected. It is also important for reducing the stigma associated with eating disorders, as this recognition underscores that these are not choices, but rather disorders that require medical and psychological intervention. As research continues to uncover the complexities of eating disorders, it is vital that our approach to treatment and prevention evolves.
By integrating knowledge of genetic, neurobiological, and physiological influences, healthcare providers can offer more personalized and comprehensive care, improving outcomes for those struggling with these challenging conditions. Remember, if you or someone you know is suffering from an eating disorder, seeking professional help is crucial. Eating disorders can have serious health consequences but with the right treatment and support, recovery is possible.