Why Stress Hurts Immunity
Stress is an inevitable part of life. The human response to stress has evolved as a survival mechanism to help us be more vigilant in hit-or-run situations. But when stress becomes chronic — which is not uncommon in modern life — it weakens the immune system and makes us more vulnerable to diseases like colds, flu and coronavirus infection — and also causes chronic inflammation in the body.
We will tell you how this all happens and what you need to know in order not to fall into the vicious cycle of "stress-disease-stress".
Stress makes fighting viruses difficult
When the immune system begins to take hold, pathogens that are normally immune-controlled take over and reproduce vigorously.
Fact!
As soon as you start feeling unwell, the stress response increases, and the immune system becomes harder to fight the disease: a vicious circle occurs.
In the 1990s, American psychology professor Sheldon Cohen and colleagues conducted a series of studies in which healthy people were exposed to upper respiratory infection by instilling rhinovirus droplets directly into their nose.
These participants were then quarantined in a hotel and closely monitored to determine which one fell ill. One of the most important predictors of the disease, the study found, was long-term psychological stress: people who were more anxious and fearful—no matter what the reason for the longer-term illness.
Cortisol inhibits immunity
"Brief stress" refers to stress that lasts minutes to hours, while "chronic stress" lasts for hours per day for weeks or months.
When faced with a perceived threat, whether psychological or physical, the hypothalamus activates the anxiety system. This causes a release of hormones, including epinephrine and cortisol.
In a typical stress response, cortisol levels rise rapidly when stress occurs and then fall to normal rapidly after it has subsided.
Fact!
In the short term, cortisol suppresses inflammation, providing the body with enough energy to respond to an immediate threat.
However, chronic stress can be very harmful in the long term.
A 2022 Harvard University study found that people experiencing psychological stress during the coronavirus pandemic are more likely to experience long-term COVID-19. The authors classified this stress as depressive tendencies, possible anxiety, perceived stress, anxiety about the virus, and loneliness.
Fact!
In study participants, stress increased the risk of long-term covid by almost 50%. In addition, blood cortisol levels were particularly high in the most severe cases of COVID-19.
Stress causes inflammation: is it good or bad?
Inflammation is a brief reaction to an injury or infection. It is responsible for moving immune cells in the body, ensuring that the right cells are in the right places, at the right time, and in the right amount. This is a very important reaction.
Immune cells also store memory of the threat so that the next time they respond, they react more quickly and effectively. First, the circulating immune cells localize the infection site and rush toward it.
Immune cells release information proteins known as proinflammatory cytokines to signal danger and call for help, and our immune system responds by neutralizing the threat.
If too many of these inflammatory chemicals are produced by the immune system in response to an infection, symptoms such as nasal congestion and runny nose can result.
What about chronic stress?
Chronic stress causes persistently high cortisol secretion, which remains high even in the absence of immediate stress. And that's what happens next.
The immune system becomes insensitive and immune to cortisol suppression, leading to increased mild occult inflammation and production of proinflammatory cytokines (intermediate proteins).
Immune cells are depleted and begin to fail. The body is no longer able to suppress the inflammatory response.
Over time, the immune system changes its way of responding by reprogramming into a "low-control" mode.
Thus, the immune system may miss early opportunities to kill threats, and recovery may take longer.
So how can stress be managed?
We can actively strengthen our immunity and natural defenses by controlling our stress levels. Instead of allowing stress to accumulate, try to deal with it in a timely and regular manner with simple techniques.
Sufficient sleep
Sufficient sleep reduces cortisol and inflammation. During sleep, the immune system produces cytokines that help fight infections and inflammation. In contrast, research by university researchers has found that sleep deficits can increase cortisol production, potentially increasing stress.
Regular sports
Exercise improves circulation of the lymphatic system (which, as part of the immune system, maintains the balance of fluids in the body) and allows immune cells to monitor for threats, and sweating eliminates toxins.
Physical activity also lowers levels of stress hormones by producing positive signals in the brain.
Healthy eating
Providing sufficient nutrients, such as B vitamins, omega fatty acids, C and D vitamins, and a full range of minerals, such as magnesium, iron, and zinc, during periods of increased stress has a positive effect on overall stress levels. Maintaining fluid balance helps the body eliminate toxins.
Communication and practice of meditation or awareness
These exercises increase the levels of endorphins and serotonin, which improve mood and have an anti-inflammatory effect. Breathing exercises and meditation stimulate the parasympathetic nervous system, which soothes stress responses, allowing us to "reset."
