The Relationship Between Chronic Stress and Immunity
Chronic stress and immunity are closely intertwined. When we experience long-term stress, it can impact our immune response in a number of different ways. These range from an increased susceptibility to minor illness, through to life-changing disease conditions. As a result of this impact, stress reduction is an important aspect of health.
The immune system is complex. It consists of a team of white blood cells, organs, chemical mediators, and antibodies, which collectively try to safeguard the body from foreign invaders that may occur in cells or in the blood.
In addition, while the immune system is very efficient at removing these invaders, including bacteria, viruses, or cancer cells, it can become compromised because of external interference, in this case chronic stress.
Acute stress is not particularly harmful to the immune system, but long-term stress suppresses the immune system so that it does not react in the way it is supposed to. Here are some ways chronic stress affects the immune system....
Reduces nutrient uptake
Many people do not realize this, but a very large part of your immune system resides in your intestines and gut. This healthy functioning is affected by having just the right microbial environment. Probiotic bacteria are considered to be beneficial, and they usually inhabit the gut. They promote metabolism of the food we eat, along with keeping not so desirable microbes at bay.
Cortisol, apart from suppressing the action of these bacteria, also causes nutritional deficiencies by speeding up movement of food. The faster food passes through the intestines, the less time it spends for active nutrient recovery to occur.
This alone has far-reaching implications for the entire body, since without sufficient nutrients for recovery to take place, you are leaving your body vulnerable to attacks from the myriad of microbes we come into contact with every day.
Cortisol resistance and enhanced inflammation
Cortisol by itself is an anti-inflammatory hormone. This is why the prescription based corticosteroid medications are used in conditions that have active inflammation; they are all synthetic versions of the prototype- cortisol.
However, when this hormone is present in blood for durations that are too long to be considered normal, the body compensates by producing more pro-inflammatory compounds. In turn, cortisol’s effects are suppressed, but not the repercussions of its actions on the immune system.
Cortisol promotes insulin resistance
While the connection may not seem obvious at first, blood sugar levels do have an impact on immunity overall.
First, having chronically high blood glucose levels causes damage to a range of cells in the body, including nerves and to blood vessels. This in turn, impairs the ability of the immune system to properly detect, and then remedy, any pathogens that may be involved in the situation.
Decreased ability to fight abnormal cells
Every single day, under normal conditions, your body destroys multiple cells that have the potential of turning cancerous, without you ever realizing what’s going on. In particular, the body produces natural killer cells (or NK cells), which are specific for these cancer cells and do a good job of keeping you safe.
However, chronic stress levels suppress production and recruitment of this cell type, so that abnormal cells may keep growing trouble free. When they are detected, the cells are unable to get rid of them in a timely manner. This is why chronic stress is associated with an increased susceptibility to some types of cancer, in some people.
Desensitisation of the brain
Part of the way the immune system functions so precisely is due to a series of back and forth messages with the brain.
However, similar to the way pain killers work, cortisol suppresses the chemical mediators that tell the brain what is going on, effectively placing a blindfold on it. At first, the brain is still able to maintain relative normalcy, but when placed under chronic stress conditions, these impulses can be blocked, leading to an inhibition of signals being transmitted.
To prevent these changes in the body, it's important to reduce chronic levels of stress. The immune system is an important aspect of staying well. Let's give it a helping hand by changing the things that we can control, and reducing chronic stress in our lives.