Stress made us who we are. As a species, we've evolved as a result of stress. Our body is designed to handle stress - our ‘flight or fight’ survival reaction was quite useful when the caveman encountered a wild animal. But in the modern world, the “always on” trend puts us in a permanent state of alert. Continuous stress became the norm and it turned against us.
The body responds to stress via HPA axis (hypothalamo-pituitary-adrenal axis) that will trigger stress hormonal cascade across multiple organs and systems.
A dog barks loudly at you, or you are about to give a talk in public. Within milliseconds, a hormonal cascade pushes your body’s machinery into a “crisis” state. To "save" your life, your body starts to produce more energy: more glucose is released from your liver, more blood and oxygen are pumped to the heart and muscles. Functions that are not immediately needed, like digestion, sex, the immune system, are slowed down. You feel your heart beating in your throat, you become extremely aware of everything around you, and feel a real boost.
The body's stress-response system is self-limiting: once a perceived threat has passed, hormone levels return to normal. Therefore your heart rate and blood pressure return to regular levels, as well as the activity of other organs and systems.
This ‘on the spot’ type of stress can be good for you because the extra stress hormones help your mind and body to deal with the situation.
But there are no nasty dogs who want to bite you every day. And that’s good, because our ‘alert mode’ is not designed to be constantly “on”.
If you are exposed too often to stressful situations, without the necessary recovery or relaxation, your body will build up stress-related tension. This chronic stress will become negative and then manifest in a variety of ways.
For example, excess cortisol will affect several regions in the brain, especially the prefrontal cortex area, that is the most sensitive to the detrimental effects of stress. The prefrontal cortex intelligently regulates our thoughts, actions and emotions through extensive connections with other brain regions, creating a “mental sketch pad”. Therefore, with chronic stress, emotional response, behaviours and decision making are affected.
These reactions to stress differ from person to person and can be influenced by our life experiences (i.e. traumatic events can make us particularly vulnerable to certain stressors) but also genetics (several genes are regulating the stress response process), although genes are not destiny.
In response to stress, the levels of various hormones and molecules change, especially those secreted by the adrenals, the ‘stress glands’.
The adrenals secrete cortisol and DHEA, steroid hormones and other molecules (adrenaline, noradrenaline) involved in stress response. They influence glucose, insulin and inflammation, and play a major role in bone and muscle building, mood and mental focus, stamina, the sex drive and sleep cycles.
When stress is prolonged, adrenals turn into a roller coaster, become overworked, get tired, lack juice and will lead you to exhaustion and burnout, along with other troubles: blood sugar and insulin imbalances, food cravings, belly fat, sleep problems, low metabolism, weakened immunity.
Everyone knows what stress is, but it's a big challenge to know where you are on the stress roller-coaster.
To understand the real impact of these stress molecules on your body, you need to rely on more than what you “feel”. Your perception of stress does not always reflect your biology.
Stress molecules can be objectively measured and this gives you clues on how to deal with stress from within (if your HPA axis has a proper functioning). When a stress occurs, there is the catecholamines cascades that starts within milliseconds:
We want to check if your diurnal cortisol secretion curve has a physiological pattern (high in the morning than decreasing all long day). We want you to keep a healthy cortisol rhythm, since it influences your response to stress, your energy level, your sleep and your sugar metabolism.
We will also check your CAR (cortisol awakening response).
The awakening response (CAR) is typically the cortisol peaking between 30 and 45 min after being awake and this peaking is a crucial reference point for a healthy cortisol circadian rhythm. It is related to stress, affective disorders, and physical health risks.
This generally affects the body‘s ability to adapt to stimuli. An important function of cortisol is activating the metabolism to mobilise energy reserves. Cortisol influences emotional stress, blood pressure, metabolism, immune response and memory formation, among other important functions.
DHEA is made of cholesterol, mainly in the adrenal gland, the same gland that secretes cortisol. DHEA balances the stress reaction caused by cortisol and thus helps to better deal with stress.
The production of DHEA decreases continually with age, from age 25 on. DHEA is also a building block of the sex hormones testosterone and oestrogen, improving well-being and vitality.
DA, part of the dopaminergic system mainly acts in a stimulating manner. It is essential for coordination, movement, memory and learning, as well as concentration and mental performance. In addition, together with serotonin, it has a mood-lifting effect and regulates the so-called reward system and therefore our drives and motivation.
Homovanillic acid (HVA) is a major catecholamine metabolite, associated with DA levels in the brain. Chronic stress alter the catecholamine pathway, including influencing the HVA levels.
HVA are typically elevated in the presence of a catecholamine-secreting tumor which are fortunately quite rare and most of the are benign, HVA levels can also be altered in disorders of catecholamine metabolism; monoamine oxidase-A deficiency can cause decreased urinary HVA values, while a deficiency of DA beta-hydrolase (the enzyme that converts DA to norepinephrine) can cause elevated urinary HVA values. Chronic stress alter the catecholamine pathway.
When a stressful situation occurs, adrenaline ensures that the muscles and the brain quickly have more energy available. It increases respiratory volume, blood pressure and the heart rate; it also increases attentiveness and general mental activity, motivation and willingness to perform.
But on the other hand, it inhibits digestion and sexual activity.
Noradrenaline has the effect of increasing blood pressure, alertness, concentration, willingness to perform, motivation and motor functions. It is also involved in the controlling a multitude of hormones.
Serotonin is an important messenger substance in the brain, mainly found in the gut nervous system and blood platelets. Serotonin is essentially responsible for our emotions. Acting together with adrenaline and dopamine, it elevates our mood and controls motivation. It also has a relaxing, sleep-enhancing and anti-depressive effect. In addition, it participates in regulating the feeling of being full and sensitivity to pain. Essential intestinal functions are also affected by serotonin.
This molecule (5-hydroxyindoleacetic acid) is a downstream metabolite of Serotonin (the liver breaks down the hormone serotonin into 5-HIAA). This transformation is influenced by several co-factors, like Vitamine B2, Manganese and ADH (aldehide dehydrogenase) and MAO-A (monoamine oxidase A) enzymes. MAO-A gene is sensitive to oestrogens (high oestrogen inhibits MAO-A and low oestrogens increase MAO-A activity with increasing the turnover of Serotonin to 5HIAA that can lead to depression, night sweats and hot flushes, symptoms that are common at menopause).
Vanillylmandelic acid (VMA) is one of the breakdown products of epinephrine (adrenaline) and norepinephrine. This transformation is influenced by several co-factors (Magnesium, Vit B2, Cupper, SAM and enzymes such as monoamine oxidase (MOA) or catechol-O-methyl transferase (COMT).
Insulin, a hormone secreted by the pancreas, is the main hormone that regulates the sugar metabolism. When stress occurs, the blood sugar is rising under the action of adrenaline and cortisol to ensure the necessary energy for this emergency state. Therefore, insulin must handle this rapid raise of blood sugar that was released to produce an extra-amount of energy needed for survival. The problem is that this extra energy is not really fully consumed (we are almost never literally running to save our lives). What’s more, because this phenomenon will occur again and again with a chronic stress, we can end up having a high blood sugar almost all the time, and consequently develop insulin resistance, with an increased risk of developing diabetes, cardiovascular disease, weight gain/obesity.
Are slowed down in stressful conditions. Decreased thyroid function is a factor in fatigue, weight gain and feeling low.
Prolonged stress leads to a lower libido and sex drive. The female reproductive cycle can also be disturbed.
Increases during acute physical stress, which can enhance metabolic activity. But chronic stress can lead to less growth hormone being secreted.