On: The pervasive effect of stress – is it killing you?
Episode: 51
Date: April 2019
Background: Neuroendocrinologist.
Key Subjects:
- Dual hormonal pathway triggered by stress stimulus:
- Immediate response – adrenalin:
- Triggers activation of parasympathetic nervous system.
- Secondary response – cortisol:
- Continues parasympathetic response (elevated blood glucose).
- Shuts down digestion, metabolism, growth hormones, reproduction.
- See also (“The Hour Between Dog and Wolf“)
- Immediate response – adrenalin:
- Narrow window of optimum level of cortisol, depends on:
- How much is released (too much or too little not good).
- How responsive you are to certain levels (type of receptors; individual biological set-points).
- Correlation between (perception of) social status and stress:
- Humans play roles in multiple hierarchies (work, family, hobbies).
- Typically, where they rank highest is the most meaningful to them.
- Correlation between personality and stress:
- Regardless of rank, combination of genetics and environment influences how you perceive certain potential stress stimuli.
- Can be seen in size and activity of amygdala.
- Three brain systems:
- Brain stem: autonomic system (breathing, body regulation).
- Limbic system: emotions, survival activities (food, sex) (amygdala, hippocampus, thalamus).
- Cortex: executive function, thinking, reasoning, planning.
- “Optimal” levels of stress stimulate:
- Delivery of energy, oxygen, synapses, memory retention.
- Relationship between (mental) health and income:
- Level of income explains large part of variability in health.
- Not necessarily or only due to lower access to health care for poor.
- Subjective view of socio-economic status is at least as good a predictor of health as income.
- Not necessarily about being poor (only), but feeling poor.
- What makes you feel poor: awareness of inequality.
- What makes you aware of inequality.
- Constant reminders in (social) media.
- Current (media) environment has potential to amplify difference.
- Causing wider spread chronic stress.
- Level of income explains large part of variability in health.
- Chronic stress:
- Strengthens (grows) the amygdala (fear, anxiety, aggression).
- Weakens (shrinks) the hippocampus (memory).
- Weakens the frontal cortex (impulse control, long-term planning, empathy).
- Fixes for chronic stress:
- Whatever you do (exercise, meditation), do it regularly rather than one-offs.
- Genetic basis for stress, depression:
- Direct linkages between genes and depression unclear.
- Similar to other complex behavior.
- Likely that certain genes make you more vulnerable to how you react to external stimuli.
- Direct linkages between genes and depression unclear.
- Stress and sleep (see “Sleep“):
- Cortisol spikes about one hour before sleep.
- Cortisol inhibits release of melatonin.
- More difficult to fall asleep, less brain restoration.
- Chronic stress causes cortisol to stay high throughout.
- Lower sleep quality.