What is stress?
Stress is an adaptation reaction triggered by a situation experienced as being new, unexpected, hostile or threatening.
From a biological perspective, stress is defined as being the range of responses mobilised by the body to enable it to adapt to pressures generated by its environment. These responses are always dependent on the perception of the individual concerned. For example, some children experience exams as a stressful situation, whereas others do not.
Quantifying stress
According to a survey1 conducted in November 2020 of 1,037 people representative of the French population over the age of 18, more than half of French adults report that they are more stressed now compared with before the start of the Covid-19 pandemic.
Stress is an integral part of personal and professional life and the levels of stress experienced are increasing year on year : almost 4 French people out of 10 report that their level of stress over the last three years has increased.
Although 9 French people out of 10 describe themselves as stressed, women are more affected (59%) than men (41%). One of the main impacts of stress is its effects on sleeping. More than a third of the French population have problems sleeping.
The different stages of stress
Since stress is a normal response to a stressor, it is not harmful so long as it occurs occasionally (e.g. the stress that an actor feels before going on stage). However, long-term stress may have significant physical and mental consequences.
Stress can be broken down into 4 stages:
1- The alarm reaction stage:
During this stage, all the senses are on high alert and the individual very quickly mobilises the bodily resources available. This corresponds to the “fight-or-flight” reaction.
Via the nervous pathway, the body releases adrenalin and prepares itself physiologically for a rapid physical response.
The individual becomes very alert to allow better interpretation of the stressor and to react more quickly. This stage requires a great deal of energy so that the body can respond rapidly.
2- The resistance stage:
When an individual is exposed to a prolonged period of stress, the body enters a stage known as the resistance stage. The high levels of cortisol released by the body stimulate the synthesis of glucose to produce the energy it needs to defend itself. High levels of serotonin and dopamine are mobilised by the body and then rapidly used up1.
The release of cortisol, as a result of a cascade phenomenon, generates a feedback effect and keeps the cortisol level stable to stop the body “going into overdrive”. At the same time, the body starts to lose magnesium via the urine.
These high cortisol levels can disrupt the immune system and the metabolisation of sugars and fats. Cortisol can also cause sleeping and mood disorders and even impair the cerebral neurons.
3- The mental exhaustion stage:
When the body is overwhelmed, serotonin and dopamine levels collapse, cortisol levels remain high and the body continues to attempt to adapt in a state of “mental overload”.
The adverse signs of stress appear: fatigue, anxiety, loss of enjoyment and impaired immune defences which make the body more vulnerable to infection.
4- The mental and physical exhaustion stage:
This stage can be described as burn out and is characterised by intense fatigue accompanied by a disengagement from professional and personal activities. This stage is particularly damaging in that it can persist for a very long time, after building up insidiously over many years, with the individual sinking into a life of chronic stress.
The individual’s mental and physical defences are completely exhausted and out of balance (due to defective cortisol secretion in the morning).
Therapies focus, of course, on treating the identified disorder, but must also address the work-life context which has led to this state of burn out.
The three signs indicative of stress-induced exhaustion:
- I feel depressed
- There’s nothing I enjoy/I’m not interested in anything
- I feel tired and I’ve no energy
Stress: its impacts on health
Stress can have extremely adverse effects on our body and on our health. Many published articles confirm that stress can initiate or aggravate a range of disorders: psoriasis, eczema, Crohn’s disease, asthma, gastric ulcer, irritable bowel syndrome, etc.
The effects of stress on the heart
The heart is very sensitive to both the acute and chronic forms of stress. It can cause narrowing of the coronary arteries, a reduction in blood volume, an increase in blood pressure, etc. Acute stress (caused, for example, by a sudden, life-threatening situation) can trigger a heart attack (or myocardial infarction - MI).
Chronic stress, on the other hand, tends to increase cardiovascular risk factors: overweight, diabetes, high cholesterol levels, high blood pressure, smoking...
Stress and overweight
Although acute stress reduces appetite, chronic stress can promote snacking behaviour. The increase in cortisol levels induces an increase in insulin and thus greater storage of fats in the abdomen.
Stress and immunity
Studies have shown that stress may impair the response of some immune system cells, such as NK (Natural Killer) cells that are essential in enabling the body to eliminate pathogenic micro-organisms.
Stress: an accelerator of ageing
The human body is in some ways similar to a metal when it is exposed to oxygen in that it oxidises (oxidative stress) and generates free radicals which degrade the cells. Stress amplifies this oxidation process and accelerates the ageing of cells, notably skin cells, leading to the development of the characteristic signs of ageing such as wrinkles.
The key roles of cortisol and magnesium: the vicious cycle of stress
As mentioned previously, cortisol plays a key role in the progression of stress. When stress establishes over a period of time, the body’s ability to regulate cortisol levels becomes impaired: the body produces more and more cortisol, in a state of permanent activation. Muscle contractions increase which promotes the loss of magnesium from muscle cells and into the blood and from there into the urine. However, insufficient magnesium levels make an individual more susceptible to stress: this is the vicious circle of stress!
Magnesium: the reflex response at every stage of stress
The micronutrient which should be prioritised in any stress management context is magnesium.
Whilst a deficiency of this mineral aggravates the susceptibility to stress, an optimal intake will, on the contrary, reduce the secretions of hormones and stress messengers and will have particular effects on muscle relaxation.
To find out why and how to optimise your intake of magnesium, watch our video:
