Updated: Jul 12
You've had been warned or casually reminded by either your doctor, a solicitous friend or someone in family, about stress. But none of them, including your doctor, have said it enough or rather convinced you to pay attention as stress is a relatively obscure mechanism and immeasurable with very little known about how it impacts your health. What is better understood is that chronic stress can impact your physical and mental health in myriad ways leading to undesired health outcomes, obesity, poor sleep and indirectly a cascade of problems including diabetes, heart disease, cancer, stroke, neurotransmitter imbalance etc.
WHAT IS STRESS?
You'd have noticed a prefix 'chronic' wherever I mentioned stress, it's because stress, generally, is not a bad thing. Stress is when our body release cortisol, a stress hormone, to deal with danger or a situation that demands survival tactics like running from a mad dog chasing you, performing a heavy squat, getting a cut or a burn, running at the last minute to attend an important meeting, speaking before a huge audience etc. A common thing in all these situation is they all need you to be alert and energetic, made possible by circulating cortisol which is responsible for activating your sympathetic nervous system aka 'Fight and Flight' response system. Sympathetic nervous system is responsible for several functions like blood clotting, releasing glucagon to provide instant energy by breaking down glycogen, releasing adrenaline, raising your heart beat to deliver blood to working muscles, all of which comes handy during stressful situation. On the other hand, parasympathetic system activates when you are relaxed, it helps in food digestion, releases insulin to digest food while suppressing glucagon and cortisol, slows down heart beat, contracts bladder etc. Both sympathetic and parasympathetic nervous system play crucial roles in our physiology, but only if they are functioning well.
The problem begins when you are stressed more than is necessary for e.g. while eating, preparing to sleep, on your way to gym. Situation of being chronically stressed could arise due to several factors which we call stressors. Stressors could be physical or psychological, beneficial or detrimental. Stressors can have a healthy response like morning jog, solving a puzzle or it can have a unhealthy response like a bullying boss, abusive or smoking etc.
Stressors with healthy physical response
Moderate alcohol consumption
Stressors with healthy psychological response
Your cricket team winning
Passing an exam
Clinching a successful business deal
Organizing an enjoyable social evening
A tight sales deadline - but not too tight
Giving a well-received lecture
Stressors with unhealthy physical response
Being a fighter jet pilot
Extreme environment change/rapid alteration in temperatures
Spinal cord injury
Stressors with unhealthy psychological response
Being dislocated from the surrounding population/culture
Money worries, long term debt
Poor social network
Your cricket team losing
Getting up on Monday morning
Low status is social hierarchy
Exposure to above stressors for a prolonged period of time could bring about respective healthy or unhealthy responses. Unhealthy stressors could lead to, what is termed as HPA-axis dysfunction which is the root cause of long term chronic stress and metabolic dysfunction.
What is HPA-axis?
HPA-axis is the three part hormonal system consisting of hypothalamus (located at front side of brain), pituitary (located below hypothalamus) and adrenal (located above kidneys). Hypothalamus synthesize CRF (corticotropin releasing factor) which, in response to stress, bind to receptors in pituitary which, in turn, secretes ACTH (adrenocorticotropic hormone) whose target is adrenal cortex which then release glucocorticoids which is other name of cortisol, the stress hormone. Stimulation of HPA-axis to release cortisol is regulated by negative feedback loop i.e. glucocorticoids regulates further HPA axis activation in a normal functioning HPA axis. What if this negative feedback loop stops working and there is excess amount of cortisol circulating in your body? That's what happens during HPA axis dysfunction.
What causes HPA-axis dysfunction?
A dysfunctional HPA axis results in chronically elevated cortisol levels which can have following detrimental effects:
Breakdown of muscle proteins to convert it into energy
Cortisol acts as direct antagonist to the actions of insulin which is responsible for regulating blood sugar
Redistribution of body fat which accumulates in the trunk and becomes visceral fat which is known to be the dangerous kind
Raised blood pressure
Raised VLDL and triglycerides levels
Suppresses your immune system
Increased risk of Heart Disease
As per Dr Malcolm Kendrick in his famous book, 'The Great Cholesterol Con', he sheds light on three initiators of HPA-axis dysfunction based on available evidence:
Spinal Cord Injury
It is found that in above three conditions body has excess circulating levels of cortisol and possible link to HPA-axis dysfunction. Spinal cord injury may initially not seem to have anything to do with HPA-axis dysfunction, but it has. This is because if you break vertebrae and snap the spinal cord, you usually destroy many sympathetic and parasympathetic nerves at the same time. Dr Kendrick talks about 'Social dislocation' as a critical stressor that may lead to severe stress and studies support that displaced populations like immigrants Asians in America and UK or indigenous tribes who were thrown at the bottom of social and economical hierarchy have much higher rate of heart disease. I strongly recommend reading his book to understand more about the root cause of heart disease, Stress.
Your Best Bet against Stress and Heart
Exercise - There is a massive amount of literature to demonstrate very cleraly that exercise is one of the best things you can do to protect your HPA axis. Start with a good strength training program and combine it with moderate level of cardio.
Take active steps to identify stressors that are disturbing you and take corrective steps.
Moderate levels of alcohol (specially wine) can help fix dysfunctional HPA-axis and reduce stress. As if you needed a reason !!
Breathing exercise have shown to reduce stress, there are many breathing techniques to choose from.
Take steps to improve your sleep, get at least eight hours of daily sleep.
You can also take pro active steps to deal with stressors which may be omnipresent for so many of you. Go for a walk, get some sunlight, plan enjoyable evenings, be a part of community that you enjoy, join a club, leave that stressful job and start the one you love, make friends. These are potent steps you can work on to not just improve quality of your life but also to keep deadly chronic diseases at bay.
When excess cortisol is produced, protective negative feedback loop of HPA-axis is broken. https://www.ncbi.nlm.nih.gov/books/NBK278995/
Effect of moderate level of white wine on HPA-axis. https://pubmed.ncbi.nlm.nih.gov/11701194/
HPA-axis response to stress. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3181830/
Book, 'The Great Cholesterol Con', Dr Malcolm Kendrick
Post traumatic stress disorder and Breathing. https://academic.oup.com/jcem/article/98/7/2984/2537196