Stress and fatigue Flashcards
What is stress?
Non-specific response of body to any demand
What is the difference between acute and chronic stress?
Acute – quick recovery, alarm reaction, may save your life
Chronic – no recovery, constant stress, impairs immunity
What is general adaptation syndrome?
1) alarm stage – body’s defences are reduces
2) activation becomes chronic from alarm reactions to stages of resistance (defences are elevated)
3) stage of exhaustion – defences are reduced again.
What 5 factors does modern lifestyle expose us to?
noise, less family support, less rest, more information, more toxins
Explain what happens during a stress response.
Rapid activation of SNS by hypothalamus, which activates adrenal medulla and releases adrenaline and norepinephrine into blood. Hypothalamus also activates adrenal-cortical systems by release CRF, this activates pituitary to release ACTH which triggers adrenal cortex to release cortisol.
What does ACTH stand for?
Adrenocortisotropic hormone
What 6 responses are there in the alarm phase?
Increases arousal, cognition, increase b.p, h.r, suppress appetite, inhibits digestion and growth, immune function
What is the function of aldosterone?
increases water retention and blood pressure
What is the functions (5) of cortisol?
Increases glucose production, increase protein catabolism from muscle, increases vessel sensitivity, reinforces autonomic NS response, decrease inflammation response and Th1 immunity
What are the consequences of chronic stress?
Long term activation of HPA leads to adrenal exhaustion and hypo-activation
Hippocampus is desensitized and damaged resulting in prolonged alarm reaction so overproduction of cortisol which inhibits reproductive axis, growth hormone release and thyroid axis.
What are 5 physiological stressors that stop a person from coping with stress well?
inflammation, insulin resistance, obesity, endocrine disruptors, immune system
What are 5 symptoms of adrenal dysfunction?
Low energy at 3-4 pm, anxiety, cognitive dysfunction, decreased libido, caving sugar/salt
What are 5 disorders associated with HPA dysfunction?
anorexia nervosa, increased stress system, hyperthyroidism, panic disorder, depression
How does stress suppress the thyroid?
Increase CRH and cortisol decreases the production of TSH and glucocorticoids inhibit enzymes 5-deiodinase (this enzymes converts inactivates thyroxine into active triiodothyronine)
How does stress suppress the reproductive function?
CRH suppress secretion of GnRH (gonadotropin-releasing hormone)
Glucocorticoids inhibits GnRH neuron which renders target tissues (gonads/pituitary gonadotroph) resistance to hormones
How does oestrogen contribute to stress?
Oestradiol (high levels) increase basal concentration of cortisol and ACTH.
Explain why psychological stress leads to oxidative stress.
Psychological stress can lead to a increase in reactive oxygen spp, increase activity of neutrophils causing release of oxidative metabolites and proteolytic enzymes
Glucocorticoids also increase glutamate and calcium and decrease antioxidant activity
How can prebiotics help with stress?
lowers salivary cortisol, increases BDNF (growth factors for hippocampus which shrinks when chronically stress), reduces anxiety
How can probiotics help with stress?
provide bacteria which normalises noradrenaline and anxiety levels
What are 5 symptoms of stress?
Depression, fatigue, headache, upset stomach, digestive disturbances
What is the adrenal stress index testing?
it tests both saliva cortisol and DHEA levels and their ratios
What are low levels of DHEA linked with?
depression, low sexual thoughts, osteoporosis, cancer, impaired learning, impaired learning and memory
What property does DHEA have?
It has anti-glucocorticoid activity
Explain how cortisol increases blood pressure/
Cortisol causes blood glucose to be released in the blood by gluconeogenesis, decreasing insulin sensitivity, amino acid catabolism
What should be avoided in chronic stress?
alcohol, drugs
caffeine - amplifies cortisol production many hours after ingestion
Explain what nutrients should be increased when chronically stressed.
Magnesium – reduces activity of HPA axis which decrease CRH and ACTH, inhibits NMDA receptors in NS which reduces excitation
Potassium – increases ratio K: NA by 5:1
Omega 3 – reduce anxiety symptoms
B6 – deficiency increases overall psychological stress
AA – tyromine and taurine
Phosphatidylserine – reduces ACTH and cortisol (serum and salivary)
Inositol – reduces hyperarousal of HPA axis
Vit E – protect adrenal cortex from free radicals and reduces cortisol production
What 2 nutrients should be increased when you have hypo function of adrenal cortex?
B5 – part of coenzymes A and necessary for fatty acid synthesis; co enzymes A is important for formation of cortisol
Ascorbate – helps to converts cholesterol into pregnenolone which converts to cortisol, DHEA
What is a herbal adaptogen?
Non-specific, normalizing effects on physiology
What are 5 functions of Rhodiola Rosea?
Improves oxygen carrying capacity of blood, increases stamina and endurance, increases serotonin and dopamine levels, reduces freq of migraines, increases physical work capacity
What are 4 functions of panax ginseng?
Improves mental fatigue, increased glutathione levels, decreases ROS, improves physical performance
What is the mechanism for ginseng?
Increases serotonin, dopamine and increases HPA axis, vasodilation so improve oxygen availability, improve antioxidant stasis
What is the function of liquorice?
increases and preserved the availability of cortisol
What needs to be cautioned with liquorice?
Excessive urination, nocturia and hypotension
What is the mechanism for liquorice?
Liquorice is a competitive inhibitor of 11beta-HSD2 which converts cortisol to cortisone.
What are 5 causes of chronic fatigue syndrome?
Viral infection, impaired immune function, low adrenal function, impair liver function, depression, food allergies
How is fibromyalgia different from CFS?
Similar pathophysiology and symptoms but people with FM have significant pain (weakness, burning, aching, pressure)
What is the theory of CFS development?
Limbic kindling – chronic stress leads to hyperarousal which leads to hypocortisolism; stress may also contribute to oxidative stress
What are 2 metabolic processes of ATP production?
krebs cycle and electron transport chain
Explain how ROS impairs ATP synthesis.
ROS damages the mitochondria when ROS production outpaces antioxidant activity. Mitochondria impairs ATP synthesis.
What are 5 essential nutrients for mitochondrial function?
coQ10, magnesium, b vitamins, ALA, Essential fatty acids
How does ALA improve mitochondrial function?
Lipoic acid forms a part of complex V within the ETC, it increases glucose uptake into cells to be used as energy, increases pyruvate, protects mitochondrial structures.
How does CoQ10 help with mitochondrial function?
shuttling of electrons along ETC
How does magnesium help with energy production?
Mg transfers phosphates from ADP to ATP which is essential to create energy
How does EPA and DHA help with energy production?
EPA – induces mitochondrial growth, size and distribution
DHA – essential for ETC complexes
What are 6 lifestyle factors we can suggest to improve energy?
Regular, adequate amount of sleep, relaxation, good work life balance, increase physical activity, avoid alcohol and drug and limit caffeine
What are 4 reasons cortisol may be produced?
excessive heat/cold, physical trauma, exercise to a point of exhaustion, extreme mental anxiety
