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A stressor is anything that disturbs homeostasis. It could be physical, psychological or social. It perturbs the present moment, so it can change direction. There is no doubt that some stress is necessary to compel us to move and perform, it is called "eustress good stress." But, stress can take a toll on the cardiovascular, immune, memory & reproductive systems and age us faster.
Stress & the Heart:
When we are being chased by a large hairy creature in a dark forest, the stressor’s effect on the heart makes it more efficient. The stress chemicals empty fat and sugar storage houses in the blood to provide immediate energy. The increase in heart beat allows for a rapid circulation delivered where it is most needed like to muscles so we can run faster. However, if the stressor is chronic? The result is chronically elevated blood pressure which puts a lot of stress on small vessels in your body. This causes so much damage! Stress can promote blood vessel damage such as inflammations and increasing plaques. Also, stress chemicals make the blood viscous like honey. So, you now have narrower vessels, with high blood pressure, circulating fat and sugar that is stuck in the viscous blood. This can amount to a disaster if the blood supply becomes too slow or is completely obstructed from getting to an organ like the heart or the brain. Sometimes short-term stress can also be so immense that it can cause a lot of damage. Not surprisingly, a strong forceful emotion like anger doubles the risk for a heart attack during the subsequent two hours.
Stress & the Immune System:
A part of the stress response to moderate stressors is shutting down the immune system. At the beginning shortly after a stressor, there is an enhancement in the immune response, if the stressor remains beyond an hour or so, the immune system is closed until it goes back to pre-stressor levels. However, if the stressor remains for even longer, the immune system continues to decrease beyond baseline. This chronic stressor related immuno-suppression is far from benign. This explains why we easily get sick when under stress. Paradoxically, a particular pattern of stress is related to a super activated immune system and autoimmune diseases that starts to fight healthy parts of our bodies. An on-off-on-off series of short-term stressors trick our stress response in remaining in the enhancement stage. Because, before leveling off back to baseline, another stressor arrives, so the system remains in the enhanced stage where the autoimmune system is over active and ejects many false positives.
Stress & the Memory System:
Short-term stressors sharpen the memory system thus facilitating our decision making and other cognitive and sensory abilities. On the other hand, in long-term stress, the stress chemicals accumulate in the brain and cause damage to memory brain areas such as the hippocampus. These chemicals encourage the forgetting circuits and obstruct the remembering ones (for more on stress & forgetting, click on this).
Stress & Reproduction:
Infertility is defined as not being able to get pregnant after one year of trying. According to the American Pregnancy Association, it affects about 10-15% of couples in the USA. In many cases, there is absolutely nothing pathological in the couples’ reproductive systems. Unfortunately, stress shuts down the entire reproductive system, by inhibiting key chemicals such as follicle stimulating (FSH) and luteinizing hormones (LH). It turns out that stress is an excellent birth control pill!
Stress & Aging:
Each organ ages differently and stress negatively affects all of them. One stress chemical that is toxic when it accumulates (as in chronic long-term stress) is glucocorticoids (e.g. cortisol). It is so fatal that it is directly related to the death of salmon after spawning. After reproduction, the high glucocorticoid levels damage many tissues in salmon including adrenal gland, kidney, immune and digestive systems. Glucocorticoid toxicity also accelerates the aging of the brain. Most prominently, brain areas involved in cognitive and sensory abilities such as memory, decision making, multi-tasking, flexible thinking and reaction times are first to be compromised.
There are many stressful situations that promote strength and confidence. The criteria are: stress you can tolerate, mange successfully, and have control over. When these elements in a stressor are lacking, then stress can lead to poor quality of life and premature death. One lesson to be learned from salmon is that stress can kill us in a very tragic way.
