The adrenal glands are two small glands that sit on top of the kidneys. Their function is to react to signals from other organs in the body and to send out signaling substances, partly via the bloodstream but also via the nervous system.
The adrenal glands have three layers that produce different types of hormones or signaling substances. Sex hormones, hormones that help regulate mineral levels, blood sugar and blood pressure are all produced in the adrenal glands (all of these are also regulated via other so-called feedback systems in the body).
In traditional Chinese medicine, the adrenal glands are considered to belong to the kidney energy.
The natural clock
The adrenal glands secrete (manufacture and send out to the rest of the body) the hormone cortisol according to a rhythm over the day and many other hormones are in turn affected by the cortisol. All hormones are affected by and react in rhythms with each other. These rhythms have originated in our species Homo sapiens here on Earth, and are set according to the circadian clock.
Light receptors in the eyes and skin set off cascades of hormonal pathways in us. Cortisol is very easily affected by changes in e.g. light exposure.Healthy cortisol levels peak in the morning and then fall during the day with a small peak at midday (if you are really healthy). It should be low at bedtime and lowest during the night.
Natural vs artificial light - affects our hormones
During our time as a species, we have lived for a very short time with artificial light. Nowadays, we are believed to have existed for at least 250,000 years - and have also inherited genes since long before that. This means that perhaps 10,000 generations may have lived since then. At the end of the 19th century, electric light begins to be used in larger cities, but it would take until the 20th century before electric light was available outside in the cottages. So just 4 generations ago.
Three generations have lived with TV, e-mail and computers began to be used on a larger scale in homes as late as the 1990s. Only one (1) generation has been born and raised with portable bright, connected screens 24/7. We are not adapted to that kind of light around the clock, and our sensitive hormonal systems pay the price: i.a. sleep difficulties, anxiety and depression well into old age, fertility problems, diabetes (affected by light-controlled melatonin dancing together with cortisol), cancer and obesity.How is the nervous system affected by stress?
If over time you are up late at night, eat late at night, look at screens with artificial light or stay in an environment with artificial lighting, cortisol and other hormone levels will be measurably affected.
Other factors are infections, inflammation, nutritional deficiencies, environmental toxins, emotional stress, lack of natural light, hard, one-sided or training with unnatural load and noise.Cortisol helps us fight disease, keeps us awake, alert and strong. If we get enough rest & adequate exercise, spend time with loved ones and sleep well, the adrenal glands and our so-called HPA axis recover.
But if the adrenal glands are triggered to pump cortisol in high amounts and at the wrong times of the day, we end up in exhaustion – cortisol is constantly low. Signs of it can be recurrent infections, difficulty healing inflammation, irregular periods, infertility, autoimmunity, lethargy, soreness after exercise and many other symptoms.
Read more about recovery
The next article on adrenals & stress will be about supplements and other biohacks. How you can recover from stress, get better sleep, prevent injuries and exhaustion and optimize your stress axis and thus your hormonal systems.