Modern day fast-paced lifestyles and technological advancements mean we are literally “plugged” in 27/4, whether we choose to admit this or not. Smart phones, lap tops, tablets, ipods, the latest game consoles and satellite TV, all demonstrate our continual reliance on technology for both work and pleasure. The problem is, we are very rarely switching off, or “unplugging” from our cyber lives and it’s having a drastic effect on our long-term health.
These technological lifestyles are usually accompanied by a diet of coffee, nicotine and fast food followed by an incessant need of binge drinking at the weekend and lack of sleep, adding further to the growing problem of poor health in our modern day society. The compound effects of all these factors, together with family & job stress/pressures, leaves most people in what is known as a sympathetic dominance and at the resistance stage of stress.
The Autonomic Nervous System
The Autonomic Nervous System (ANS) is a division of the Peripheral Nervous System (PNS) (the other division being the Somatic Nervous System), which alongside the Central Nervous System (CNS), make up the wider Nervous System. It controls all functioning below the level of consciousness by conveying sensory impulses from the blood vessels, the heart and all of the organs in the chest, abdomen and pelvis via nerves to other parts of the brain (mainly the medulla, pons and hypothalamus). These impulses then elicit appropriate reactions of the heart, the vascular system, and all the organs of the body to variations in environmental temperature, posture, food intake, stressful experiences and other changes to which all individuals are exposed. This is achieved through the nerves of two branches of the ANS – the Sympathetic branch (the fight or flight branch) and the Parasympathetic branch (the rest and digest branch). The sympathetic nerves stem from the middle of the spinal cord and reach out to their target organs, whilst the impulses of the parasympathetic system reach the organs of the body through the cranial nerves (75% of all parasympathetic fibers arise from a single cranial nerve: the vagus nerve) and some sacral nerves. Through these nervous pathways, the autonomic nerves provide stimuli resulting in largely unconscious, reflex actions, which allow for adjustments and therefore allow a balance (homeostasis) in the machinery of the body. The ANS regulates actions such as pupil dilation/constriction, digestive functions (also regulated by the Enteric Nervous System (ENS)), dilatation or constriction of the blood vessels, heart and breathing rates, body temperature, the production of sweat, saliva and tears, as well as electrolyte and fluid balance.
The modern day human being is so caught up in the “rat race” of life they often end up in a sympathetic dominance. This continual stimulation of the sympathetic nerves causes an imbalance in the body’s chemistry and results in an array of problems such as poor digestion, adrenal insufficiency, mitochondrial disruption, oxidation damage, muscle breakdown, ammonia toxicity, inflammation, reduced bone density, immunosuppression, salt and water retention, extracellular fluid volume expansion, potassium depletion, metabolic alkalosis and more. An imbalance in the autonomic nervous system leads to hundreds of symptoms from digestive disorders and sleep disturbances, to anxiety, depression, blood sugar problems, high blood pressure, sexual dysfunction, neurological damage, heart disease and even cancers in the long-term.
Initial arousal of the sympathetic nervous system sets off a cascade of events, which go something like this:
Within a fraction of a second the brain has acknowledged something new has happened and upset the equilibrium. The new stimulus is processed then received by the hippocampus and amygdala, where it’s perceived as being pleasant, unpleasant, or neutral (in this case unpleasant). Next comes the input from the frontal lobe of the cerebral cortex, which provides a final edit on the initial take by the hippocampus and amygdala. This has taken less than a second and is accompanied by a cascade of changes throughout the body. At this point the Hypothalamus-pituitary-adrenal (HPA) axis (activated during physical and social stress, but via different pathways), working with the sympathetic nervous system, causes the release of a series of hormones including epinephrine (adrenaline) norepinephrine (noreadrenaline), corticotropin releasing hormone (CRH), cortisol (and other glucocorticoid hormones).
Your brain is now on red alert and the blood is awash with stress hormones. Your heart begins to beat faster, pupils dilate and you sweat as a result of epinephrine (adrenaline) release. Norepinephrine “excites” the brain, making it more susceptible to stimulation and primes it for activation, whilst the slower release of glucocorticoids supress the immune system and reduce inflammation (which may be as a result of an injury). Glucocorticoids also cause further release of norepinephrine from the locus ceruleus. In a circular feedback loop, the locus ceruleus also sends projections back to the amygdala, telling it to release more CRH, this leads to more glucocorticoids, which activate the locus ceruleus further, and so on. In the long-term (the sympathetic dominant), Glucocorticoids deplete the norepinephrine released throughout the brain and since norepinephrine makes you feel alert, attentive and mentally energetic, low stores will leave you feeling dull, unable to concentrate and give you a sense of apathy – all symptoms of depression. Stress also reduces the amount of serotonin in the brain. This neurotransmitter allows you to relax, regulates sleep and buffers mood. In addition, stress reduces the amount of serotonin receptors in the frontal lobe, meaning they are less responsive to the dwindling amounts of serotonin that do arrive. In short, low serotonin levels means more tension, worse sleep and even more vulnerability to low mood. Small, manageable doses of stress lead to the release of dopamine (neurotransmitter associated with pleasure), which gives rise to the “high” associated with something like a bungee jump. But, prolonged exposure to glucocorticoids flattens dopamine production and, as the classic criterion for depression says, there is a loss of enjoyment in activities once found pleasurable.
Consequential changes in the cardiovascular system due to sympathetic activation, result in blood being shunted from the interior of the body to the major muscles. It is a fact that the emotion of fear will result in more blood being directed to the legs, in order to run away (flight), whilst the emotion anger, will see blood being shunted to the arms, ready for action to defend (fight). The bronchioles of the lungs dilate, to allow for more gas exchange (you may notice you tend to hold your breath when you’re anxious). This is to extract as much oxygen as possible for supply to the blood and subsequently, to all areas of the body. During SNS activation the digestive system is compromised, as peristalsis (a series of muscle contractions that occur in your digestive tract) slows, resulting in constipation over time. Blood sugar rises in response to increased demand for cellular fuel, with long-term effects resulting in insulin resistance. Reproduction is compromised - the production of reproductive hormones in women decreases, and erections in males are suppressed.
The effects of SNS activation diminish slowly, unlike the effects of PSNS activation, which diminish precipitously, due to the SNS hormones being unable to regulate their own synthesis (no negative feedback loop). Because these hormones remain elevated for long periods of time (in the sympathetic dominant), the body cannot continue with the normal functioning of metabolism, which results in poor digestion and assimilation of nutrients from your food, supressed immunity, low sex drive, poor sleep quality and that’s just for starters! Chronic activation of the SNS burdens five major systems of your body: gastrointestinal (risk of ulcers, colitis, IBS, diarrhoea, constipation, impacted bowel), immune (weakens the body’s defences and leaves it open to attack), cardiovascular (hardening of the arteries, heart disease and heart attack), endocrine (increased risk of type II diabetes, impotence, low sex drive, premature aging) and nervous (anxiety, depression, mood swings, irritability and a decrease in cognitive function).
So, what’s the answer? Strengthening the parasympathetic nervous system (PSNS) and inhibiting the SNS somewhat, will provide for a return to balance, keeping you one step ahead of disease and degeneration. Meditation, relaxation, breathing exercises and even yawning, will allow activation of the PSNS. As well as practicing these techniques, you should cut out all stimulatory foods and drinks, including caffeine, alcohol, chocolate, dairy, processed foods, table salt, sugar and flour. Balancing the intake of calcium, sodium, magnesium and potassium will in turn, allow for a balance in the autonomic nervous system.
Calcium stimulates the sympathetic nervous system (SNS) Magnesium inhibits the sympathetic nervous system (SNS) Potassium stimulates the parasympathetic nervous system (PSNS) Sodium inhibits the parasympathetic nervous system (PSNS)
On activation, the PSNS dilates blood vessels in the gastrointestinal tract, thereby aiding digestion. It stimulates salivary gland secretion, increasing peristalsis, which assists in the absorption of nutrients from your foods. This branch of the ANS also increases insulin sensitivity, decreases heart rate and improves the immune, circulatory and endocrine systems.
When the organism feels safe, as opposed to when it is in an energy-conservation mode of self-protection or defense, rest becomes possible. "Without external challenges, [the DVC]... optimizes the function of the internal viscera" (Porges, 2001, p. 17). The PSNS, which initially consists primarily of the dorsal vagal complex (DVC), stimulates the secretion of digestive enzymes in the presence as well as in the anticipation of food (Braunwald et al., 2001). It furthers digestion by stimulating intestinal motility and peristalsis to move food through the digestive tract, and relaxes intestinal sphincters (Ganong, 2001). In most tissues, the activities of energy storage and digestion are facilitated by the presence of insulin, which is also stimulated by the PSNS (Ganong, 2001).
"Often, it is during the parasympathetic state, including daydreams,...[and] doodling, that things start to "make sense", and when we have a clear insight... about seemingly disparate thoughts and experience (Olsen, 2002, p. 51).
During periods of low threat, stored energy is available as the substrate for less essential activities such as social engagement (Porges, 2001), growth, and reproduction (Ganong, 2001). During periods of rest and PSNS activity, the opportunity for the integration of information also becomes possible, in part because of low levels of norepinephrine, which interferes with certain types of memory storage (Scaer, 2001, p. 15).
The Parasympathetic Nervous System & Acetylcholine
The primary hormone/neurotransmitter of the PSNS is acetylcholine (ACh). Acetylcholine aids the ANS in seeking equilibrium by assisting the regulation of heart rate, digestion, respiration rate, salivation, perspiration, pupil dilation, the discharge of urine and sexual arousal. Acetylcholine is also associated with memory and learning and is in short supply in subjects with Alzheimer's disease. Magnesium and calcium work in unity with ACh and help to keep levels in check, as ACh is an excitatory hormone and too much will over excite the nervous system (remember it’s all about balance!). Research shows us that cerebral deficiency of thiamine (vitamin B1) contributes to the reduction of ACh levels in the brain and is a determinant in poor sexual function (low levels of acetylcholine may lead to erectile dysfunction). In the balanced individual acetylcholine activity is primarily regulated by the enzyme acetylcholinesterase. This is an important mechanism, as high levels of ACh have recently been linked to depression; further reinforcing the whole idea of how important the balance of life is!
Hormone Balancing for Stress Relief
The adrenal cortical hormones released during times of stress, suppress inflammatory processes, healing processes and the immune system. They also convert glycogen stores into glucose and elevate blood sugar levels. By cutting out processed "dead" food and consuming raw/complex/low glycemic carbohydrates, as well as high quality protein, you will help to balance the release of cortisol and control its effects. Nutrients such as Acetyl-L-carnitine and phosphatidylserine are also known for their ability to reduce cortisol production and repair receptor sensitivity in the hypothalamus. Adaptogenic herbs such as Ashwaghanda root, Basil, Echinopanax elatum, Devil's claw, Dong quai, Goldenseal, Gotu kola, Green tea, Hawthorn extract, Licorice, Rhodiola rosea, Schizandra, Suma, Valerian and ginseng will all provide a bullet proof anti-stress protocol by restoring hypothalamic cortisol receptor sensitivity. Perhaps the most well known adaptogen is ginseng of which there are three types: Asian (Panax ginseng), which produces the strongest stimulation, American (Panax quinquefolium), which soothes and Siberian (Eleutherococcus senticosus) for stamina. It is also of paramount importance to keep well hydrated, as dehydration causes cortisol levels to increase.
Keep a healthy balanced diet (for your metabolic type), and you’ll balance your ANS, which will balance the actions of hormones and in turn balance the many metabolisms of the body. It’s not rocket science, although it does take an open-minded individual to see where the benefits lie. Once you do, you won’t look back.