What is cortisol?
Cortisol is produced in the adrenal cortex region, which is the outer layer of the adrenal glands. Cortisol is synthesised from cholesterol, which is a catabolic process (building of new molecules) that requires significant energy. All lipid soluble hormones are made from cholesterol. Cholesterol becomes pregnenolone, which is then further converted into a number of different hormones produced by the adrenals and sexual organs. If cortisol is in high demand as the result of some kind of stressor, then pregnenolone becomes a much sort after resource by the body and we see the patterns of endocrine function start to unfold. Some of the many impacts of elevated cortisol on the endocrine are outlined below.
#1 Adrenals “steal from the endocrine system”
The adrenals are survival organs and so will always take priority over other organs in the endocrine system such as the thyroid and the reproductive organs. The thyroid for example is considered a metabolic organ as it regulates body temperature and metabolism. The reproductive organs obviously regulate reproduction and sexual energy. While metabolism and reproduction are important processes they are not as critical to our survival as the adrenal function. As survival organs the adrenal glands take priority in receiving the available resources to create various hormones. The adrenal glands are able to “steal” the nutrients and hormonal precursors normally shared by the entire endocrine system.
When cortisol is raised as the result of a stressor the adrenals will “steal” nutrients and hormonal precursors from the rest of the endocrine system, particularly cholesterol. As discussed above pregnenolone is the common precursor to adrenal and sex hormones, including progesterone, testosterone, DHEA and cortisol. Low production of these can lead to energy loss, infertility, low libido, bad PMS symptoms in women and many more ongoing issues. The adrenals as survival glands hold utmost priority for cholesterol and pregnenolone availability to the extent that they are even capable of taking pregnenolone from the gonads own manufactured supply. Because cortisol production limits the availability of sex hormone building blocks, stress can impact on libido. High cortisol production also takes resources from the Thyroid because metabolism is secondary to survival. Thyroid related conditions such as hypothyroidism can therefore be the result of the adrenals “stealing” nutrients that the thyroid requires.
Chronic stress causes our stress-related hormones to "steal" pregnenelone, the precursor to many of our stress hormones. Bit by but other processes start to fall apart.
#2 Impaired liver detoxification
Chronically high cortisol puts in increased load on the liver thereby decreasing detoxification pathways throughout the body. These pathways are critical in the breakdown or deactivations of our used hormones, which need to be detoxified from the body once used. Hormones are substances that have short lives. Insulin for example has a half-life of about thirty minutes in the body. Once used these hormones must be broken down and de-activated so they can be discharged or recycled. The kidneys also play a role in excreting used hormones. If they are not cleared then the impacts of the hormones can linger for as long as they remain in the blood, well past when they are no longer required.
When cortisol production is high as the result of increased stress, then the liver’s job in deactivating and detoxifying used cortisol obviously increases. The body might begin to struggle to detoxify other substances such as heavy metals, alcohol and other hormones. The vital role played by the liver in so many detoxification pathways means that if it is compromised as a result of having to process excess cortisol, then the ability to remove other toxic substances is impeded and an unhealthy accumulation in the body can occur.
#3 Decreased insulin sensitivity and insulin resistance
Stress and blood sugar regulation are inextricably linked. Both are processes are regulated by hormones produced by the adrenals, and both high and low blood sugar is a significant stressor on the body. As such if cortisol is high then blood sugar regulation suffers, meaning additional strain on the pancreas, one of the key organs that controls blood sugar through the production of the hormones insulin (to lower blood sugar) and glucagon (to bring it back up). High cortisol also causes the release of glucose thereby increasing blood sugar, feeding into a vicious cycle. If the pancreas and adrenals are constantly stimulated and begin to become overworked, then insulin sensitivity can decrease. One’s insulin sensitivity to insulin is a very important metabolic factor and low insulin sensitivity and insulin resistance can lead to obesity, diabetes, mood swings, disrupted sleep and a host of other problems.
Insulin resistance becomes a stressor on the body and adds to the negative cycle of stress on the adrenals. When insulin resistance develop, blood sugar regulation becomes dependent on cortisol production as well as insulin. Therefore it is an additional stress on the adrenals. This downward spiral feeds the following endocrine complications:
- increased testosterone in women;
- increased oestrogen in men;
- inflammation issues due to insulin blocking prostaglandin 1 pathways; and
- increasing blood pressure and blood triglycerides.
Stress impacts all of us, every single day. Sometimes we can manage it alone, and sometimes we need help from a professional. For further reading on the impacts of stress and how we can better respond to these challenges, I recommend this collection of articles from Better Help.
In this article we have only explored the tip of the iceberg in terms of the negative impacts that elevated cortisol has on the endocrine system. High cortisol has a knock on effect to virtually every organ involved in the endocrine system and to mitigate these impacts minimising stress is of utmost importance. If you need support in identifying effective ways to reduce stress and improve your lifestyle you might benefit from working with a nutritional therapist.
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