At any given moment, your brain is home to a massive flurry of activity arising from neurons, neurotransmitters, hormones, and other substances and factors that can boggle the mind. One of those factors is the stress hormone known as cortisol. Given that stress is a major health issue in America and around the world, and that we have the power to make a positive impact on the stress in our lives, it’s critical to understand the relationship between your brain and cortisol.
What is cortisol?
Cortisol is the body’s main stress hormone and is produced by the adrenal glands. It works in the brain—in the pituitary gland, amygdala, and hypothalamus in particular–to control motivation, mood, and fear, as well as manages how your body utilizes proteins, fats, and carbs, helps reduce inflammation, regulates blood pressure, is a key player in the sleep/wake cycle, and increases blood glucose levels.
Most of the cells in your body have cortisol receptors, and they respond to changing levels of the hormone. For example, if you are in a highly stressful situation, cortisol levels will be high as well, and the hormone may modify or shut down bodily functions that aren’t critical at the moment. If you are being chased by a mad dog, for example, your digestive and reproductive systems don’t need your immediate attention at that moment and will shut down.
Once the dangerous or stressful situation is over, cortisol levels should return to healthy levels, as should your heart rate, blood pressure, and other systems that have responded to the stress.
Cortisol and the brain
When stress is chronic, however, or cortisol levels don’t return to healthy levels, it accumulates in the brain, and that’s when health problems can arise. In the brain, in particular, high cortisol levels interfere with the ability of the brain to function properly.
For example, chronic stress and high cortisol can affect a person’s ability to socialize with others. It can damage neurons and cause the prefrontal cortex to shrink. That’s the area of the brain involved in learning and memory.
Another part of the brain that is impacted by high cortisol and chronic stress is the amygdala. High cortisol can cause this area of the brain to increase in size, which in turn can make you more receptive to stress and get involved in a cycle of constant fight-or-flight and be accompanied by anxiety, depression, headaches, impaired cognition, increased risk of heart disease, high blood pressure, diabetes, digestion problems, impaired immune system, sleep problems, and weight gain.
In a study published in Dementia Neuropsychologia, a team of researchers explored the effects of cortisol and other stress hormones on the brain and cognition. They pointed out that elevated levels of these hormones “are associated with memory performance decline in both normal and pathological cognitive aging.”
In a subsequent Scientific American article, the author reported on a study of more than 2,000 individuals mostly in their 40s in which it was revealed that those who had the highest levels of cortisol performed the worst on memory, visual perception, attention, and organization tests. Elevated cortisol also was associated with physical changes in the brain that are considered to be precursors to Alzheimer’s disease and other types of dementia.
The link between high cortisol levels and poor brain performance was especially high among women. It’s also important to note that cortisol does not distinguish between mental and physical stressors. Therefore, if you have a chronic condition such as arthritis or diabetes, it may cause your cortisol levels to be elevated as can emotional or mental stress.
How to lower cortisol levels
Lifestyle changes are the best ways to bring cortisol levels down. Adequate sleep, routine practice of stress-reducing techniques, daily exercise, a healthy diet, a strong social life, and avoidance of environmental toxins (including food additives, health care and household chemicals, and toxins in water and air) are strongly encouraged to help support and promote brain health.
Stress and cortisol go hand-in-hand and can have a significant and detrimental impact on brain health. Take steps to rein in cortisol levels and manage stress on a daily basis.