Cortisol is a steroid hormone. It is produced above the kidneys via the two adrenal glands. It is released during times of acute stress. It is also released during exercise. It is associated with the "fight-or-flight" response and a temporary increase in energy production at the expense of process that are needed for immediate survival. For example, cortisol inhibits insulin production in order to prevent the storing of use and promoting immediate use. This offset of the normal biochemical and hormonal levels is usually later resolved by a negative feedback loop.
However, chronic elevations of cortisol can have negative effects on nutrition (the absorption and metabolism of), immune function, and lead to the risk of chronic diseases. Other effects are:
1. Blood sugar imbalances and diabetes
This is due to the inhibition of insulin previously mentioned.
2. Weight gain
Cortisol can relocate stored triglycerides to visceral fat cells deep beneath the abdominal muscles. The aforementioned insulin suppression due to elevated cortisol levels can also lead to weight gain. The elevated glucose levels in the blood results in not all of the glucose being used immediately, which is later stored as fat.
3. Immune suppression
Cortisol works to reduce inflammation in the body. However, prolonged exposure to cortisol also suppresses the immune system. This unbalanced immune system can lead to a myriad of issues: colds, flues, food allergies, gastrointestinal problems, and an increased risk of autoimmune diseases.
4. Gastrointestinal issues
Digestion and absorption are compromised. Indigestion develops and the mucous lining becomes irritated and inflamed.
5. Cardiovascular disease
Cortisol constricts blood vessels and increases blood pressure. This can lead to vessel damage and plaque build up.
6. Fertility problems
Erectile dysfunction or the disruption of normal ovulation may be the result.
7. Brain structure and function
Effects the ratio of grey to white matter as well as the size and connectivity of the amygdala. It increases the number of fatty myelin-covered cells and decreases the production of neurones. Ideally, the brain likes to trim the fat of excess wiring through neural pruning in order to maintain efficiency and streamlined communication within the brain. The researchers found that hardening wires, may be at the heart of the hyper-connected circuits associated with prolonged stress.
The ‘stress hormone’ cortisol is believed to create a domino effect that hard-wires pathways between the hippocampus and amygdala in a way that might create a vicious cycle by creating a brain that becomes predisposed to be in a constant state of fight-or-flight. This decreases the ability to learn while making an individual more susceptible to anxiety and depression.
8. Skin and hair
Skin and hair are affected due to the compromise in the immune system and digestion.
This is not an all-encompassing list, but I hope it gets you started!