Chronic Stress 

Hans Selye MD was a doctor who studied the stress response.  He would take a rat and physically stress it by having it continually swim in swirling water.  When it started to drown he would remove it, let it catch its breath and begin the process over.  He would cause emotional stress by placing a rat in the corner with a cat on a leash, if the rat moved the cat would kill it.  He caused thermal stress by placing a rat on a rooftop in the middle of winter, let it almost freeze to death, bring it in and let it warm up, then put it outside again.  What he found was that no matter what the stressor was the response was always the same.  The response was hypertrophy (enlargement) of the adrenal glands, atrophy (shrinking) of the thymus and spleen, and ulcerations of the stomach and small intestine.  The thymus and spleen make up a large portion of your immune system.  This is why people under high stress tend to get sick easily and also develop ulcers easily.

Our stress hormone synthesis happens as follows:

Cholesterol® Pregnanelone® Progesterone® Cortisol (stress hormones)

                                            ¯             ¯

                                  Aldosterone      DHEA®Sex Hormones

As you can see, stress and sex hormones are all derived from cholesterol.  If you are under constant stress, you will make more stress hormones, and therefore you will need more cholesterol to make those hormones.  This is how stress can lead to elevated cholesterol.  When you’re continuously making stress hormones your body will decrease production of sex hormones, as well as aldosterone, this is called cortisol steal.  Lower sex hormones will lead to hormonal imbalances such as irregular menstrual cycles, infertility and low libido.  Lower aldosterone levels will prevent your kidneys from absorbing sodium and therefore spilling sodium into the bladder.  Wherever sodium goes, water follows.  This will cause dilute urine and frequent urination, as well as the craving of salt.

Stress affects sexual function as mentioned above, also sexual arousal is a parasympathetic nervous system response, whereas orgasm and ejaculation are a sympathetic nervous system response.  When you have high stress, this stimulates the sympathetic nervous system, decreasing stimulation of the parasympathetic nervous system and not allowing arousal to take place.  When Viagra was introduced in 1998, it became the fastest selling drug in the history of pharmaceuticals.  Could this because of the high stress lifestyle we live?

Insulin is the only hormone that lowers blood sugar, whereas cortisol, epinephrine, norepinephrine, glucagon and growth hormone all raise blood sugar.  Cortisol, epinephrine and norepinephrine are all stress hormones.  This is how stress will increase blood sugar, causing insulin levels to rise, to lower the blood sugar and ultimately causing insulin resistance.  “Guyton’s Textbook of Medical Physiology” states that persons with excess cortisol secretion frequently develop a peculiar type of obesity, with excess deposition of fat in the chest and head regions of the body, giving a buffalo-like torso and a rounded face called a “moon face”.  This is the “apple body shape”. 

Higher cortisol levels also block the 5’ deiodinase enzyme.  This enzyme is responsible for the conversion of the thyroid hormone T4 which is made in the thyroid, to T3, which is converted primarily in the liver and kidneys.  When this enzyme is blocked it will increase the production of reverse T3.  T3 is the thyroid hormone which has the most effect on the body.  Therefore, when cortisol blocks this enzyme it will lower thyroid function, which leads to lower metabolism and weight gain.  This could be one of the reasons people have symptoms of a low thyroid, but their TSH (thyroid stimulating hormone) is normal, as well as T4.  The T3 and reverse T3 levels are rarely checked.

 Stress will also have effects on the gastrointestinal tract.  It will decrease hydrochloric acid (stomach acid) and mucus production, slow the motility of the small intestine and increase the motility of the large intestine.  When you have a decrease in stomach acid and mucus production, this will decrease the amount of gastric protection of the stomach.  The high cortisol levels from stress will decrease immune function, therefore making it a favorable environment for Helicobacter Pylori to proliferate, and causing a gastric ulcer.  If the small intestine is slower to recover from stress the motility is impaired and constipation results.  When the large intestine is slower to recover from stress, motility is increased and diarrhea results.

 Stress will increase cardiac risk in many ways.  It will increase blood pressure.  It can increase cholesterol for production of the stress hormones as stated above.  The stress hormones (catacholamines) are detoxified through methylation, this could decrease the methylation capacity to detoxify homocysteine.  High levels of homocysteine are very toxic to the cardiovascular system.  As stated earlier, cortisol, epinephrine and norepinphrine raise glucose levels.  The higher blood sugar level will cause the release of insulin.  Insulin will increase cholesterol, LDL, triglycerides and decrease HDL.  The increase in body fat caused by stress as mentioned above is another cardiac risk factor.

 Cortisol has a half life of 100 minutes.  This means that if you are under stress and have a cortisol release, in 100 minutes you will have 50% of that cortisol still in your system, after 200 minutes 25% and so on.  If you are under constant stress you will continuously have high cortisol levels and have the physiological responses of that cortisol.

 We have natural cortisol patterns.  Cortisol should be very high at 8:00 am, this is supposed to get you up feeling bright eyed and bushy tailed.  It should continually lower throughout the day and be very low at night so you can fall asleep, sleep deeply and restfully.  Cortisol levels at 8:00 am are approximately ten times higher then at midnight.  There are three patterns of stress people fall into.  The stressed and wired, the stressed and tired, and the tired then wired.  The stress and wired group are people who continually have high cortisol levels.  This is the always on the go type person.  The stressed and tired group, are people who have continually low cortisol levels.  These are people who are tired from the time they wake up to the time they go to bed and are constantly seeking stimulants to keep them going.  The third type, the tired then wired group are people who have low cortisol levels in the morning and high cortisol levels at night.  These are the people who need stimulants to get themselves going in the morning, then calming aids (alcohol, sleep medications) to go to sleep.  If you suspect you have this problem click here to download a screening questionnaire.

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