Hormones & Diet Flashcards
(21 cards)
Hormones
Hormones are organic chemical messengers produced by endocrine glands. They are released into the bloodstream, travel to target organs, and help regulate, integrate, and control various bodily functions and behaviours.
Hormones vs. Neurotransmitters
Both hormones and neurotransmitters act as chemical messengers. However, while neurotransmitters transmit signals over short distances within the nervous system, hormones travel through the bloodstream to affect distant organs, influencing overall physiology and behaviours.
Hormonal Influence on Behaviours
Hormones do not directly cause behaviors; instead, they modify how our body’s systems respond to stimuli. By affecting our sensory input, central processing (CNS), and output systems (e.g., muscles), hormones alter the likelihood that specific situations will
trigger particular behaviours.
Input, Integrators, and Output Systems
Input Systems: Sensory systems that receive environmental stimuli.
Integrators: The central nervous system processes and interprets these signals.
Output Systems: Effectors (like muscles) execute responses.
Hormones modulate these systems to influence behavior in context.
Causes of Hormonal Changes
Hormonal levels can change due to factors such as diet, weight fluctuations, exercise, high stress, puberty, aging, menstrual cycles, and certain diseases. These shifts can, in turn, affect mood and behaviours.
Behavioural Effects of Hormonal Changes
Variations in hormone levels can lead to changes in mood, energy, anxiety, irritability, depression, aggression, attachment, and sleep patterns, altering the way individuals interact with their environment.
Testosterone and Aggression
Testosterone is often linked to aggressive behavior. While higher testosterone levels may be associated with increased aggression, its levels naturally fluctuate (e.g., rising before competitions) and are influenced by environmental stimuli, making the relationship complex rather than directly causal.
Ellis (2003) on Testosterone
Ellis proposed that elevated testosterone levels reduce the brain’s sensitivity to environmental cues, leading to diminished emotional control. He argued that the “competitive-victimizing” effects of testosterone have evolved through natural selection, influencing behaviour in contexts like aggression
Dopamine and Reward
Dopamine is a neurotransmitter involved in the dopaminergic pathway that produces feelings of pleasure and reward. It reinforces behaviors by making them feel satisfying, and alterations in dopamine levels have been linked to addiction, aggression, and even criminal behaviour.
Couppis & Kennedy (2008) - Dopamine and Aggression
Couppis & Kennedy (2008) investigated how dopamine reinforces aggressive behavior in mice.
Key Findings:
Aggressive encounters increase dopamine release in the mesolimbic reward system, making aggression rewarding.
Mice self-administered aggression, suggesting that fighting became a reinforced behavior.
Dopamine antagonists (blocking dopamine activity) reduced aggressive behavior, confirming its role in reinforcement learning.
Implications for Humans:
Suggests that in some individuals, aggression can be pleasurable, leading to habitual violent behavior.
Could explain pathological aggression and antisocial personality disorder.
Serotonin and Mood Stability
Serotonin is essential for regulating mood, promoting well-being, and maintaining happiness. Low levels of serotonin have been associated with increased aggression and are linked to criminal behavior, as they interfere with effective communication between brain cells.
Moir & Jessel (1995) - Serotonin and Aggression
Key Findings:
Low serotonin levels are strongly linked to violent and aggressive behavior.
In studies on animals and humans, serotonin depletion led to increased aggression and impulsive actions.
High testosterone + low serotonin creates a dangerous combination for aggression.
SSRIs (Selective Serotonin Reuptake Inhibitors) that increase serotonin have been shown to reduce aggression.
Significance:
Supports the idea that biological factors contribute to aggression, not just environmental influences.
Suggests that treatments targeting serotonin regulation could help manage violent behaviour.
Scerbo & Raine (1993) - Serotonin and Criminal Behaviour
Key Findings:
Violent criminals showed significantly lower serotonin levels compared to non-violent individuals.
The strongest correlation was found between low serotonin and impulsive aggression (rather than premeditated violence).
Individuals with Antisocial Personality Disorder (APD) also had reduced serotonin activity.
Implications:
Provides biological evidence for the role of serotonin in criminal and aggressive behavior.
Suggests that serotonin dysfunction contributes to poor impulse control in violent individuals.
Supports the use of SSRIs in treating aggression-related disorders.
Diet’s Impact on Behaviour
Poor nutrition can affect concentration, learning, and overall mental health, potentially leading to violent or aggressive behavior. For example, inadequate diets in prison settings have been linked to worse physical and mental health outcomes, thereby influencing behaviour.
Sugar and Behaviour
Excessive sugar intake can cause significant mood fluctuations and is addictive—similar to drugs like cocaine. High sugar consumption reduces dopamine release over time, contributing to anxiety, aggression, hyperactivity, depression, fatigue, memory issues, and various physical health problems.
Trans Fats
Trans fats are artificial fats created by hydrogenating vegetable oils. They are considered toxic and have been linked to health risks such as Type-II Diabetes, cardiovascular disease, obesity, and inflammation. Trans fats can also negatively affect mood by increasing depression, anxiety, and irritability
Vitamin C
Vitamin C supports the body’s ability to handle stress, lowers blood pressure, and boosts the immune system. Adequate levels help improve resilience and overall mood. It is abundant in fruits and vegetables like oranges, bell peppers, and broccoli.
Omega-3 Fatty Acids
Omega-3 fatty acids are essential fats that help build and maintain healthy cell membranes—especially in the brain. They reduce inflammation, promote new cell growth, balance blood sugar, and are linked to improved mood and a reduced risk of depression. Sources include oily fish, nuts, avocados, flax seeds, and walnuts.
Zinc
Zinc is a vital mineral that works with Omega-3 fatty acids to metabolize fats, carbohydrates, and proteins. Low zinc levels are associated with depression, and adequate zinc intake—found in foods like spinach, beef, and oysters—is important for both physical health and mood regulation.
Magnesium
Magnesium helps convert food into energy and supports hormone functions related to bone health and stress regulation. Adequate magnesium levels can improve mood and reduce stress, while deficiencies may contribute to low mood. It is found in leafy greens, brown rice, and nuts.
Bernard Gesch (2002)
Bernard Gesch researched the link between diet and antisocial/criminal behavior. He developed nutrition-based intervention programs for offenders, demonstrating that improved nutrition can lead to better mental and physical health outcomes and even reduce recidivism in prison populations.
