How to eat to manage stress

Nutrition can't eliminate stress but it can normalise cortisol levels so your body can cope

You might know your cholesterol, blood pressure and blood sugar levels, but do you know your cortisol levels? And should you?

It’s called the stress hormone, but stress can cause cortisol to plummet as well as soar. Both scenarios can have serious consequences for health, including mental health.

What stress does

Stress is the bell that rings in your brain and is heard by every cell in your body. It vibrates through your blood vessels, making your arteries stiffen and your blood pressure rise. That’s just the start of it.

The body’s response to stress is activated by the hypothalamic-pituitary-adrenal (HPA) axis. The hypothalamus is a gland in the brain that tells the pituitary gland to produce the hormone ACTH, which in turn tells the adrenal glands to produce hormones in response to stressful situations, or just mere thoughts. Cortisol is the main hormone produced.

What cortisol does

Cortisol prepares you for action. It doesn’t differentiate between psychological and physical stress; the response is always the same. Blood sugar rises, to give you more energy to fight or flee, and the heart pumps faster to get more oxygen and nutrients to muscles. Energy is routed away from non-essential functions, such as digestion. Breathing increases, and the respiratory passageways widen to accommodate more air, and therefore more oxygen. Blood clotting agents are mobilised, in case of wounding. Pupils dilate, to improve vision.

The stress response is a hugely spectacular feat of biochemical engineering, even if you are too busy panicking to appreciate how awesome it is.

Cortisol isn’t just a stress hormone. It’s what gets you up and running in the morning, all being well.

Normally, cortisol is produced cyclically in what is called the circadian rhythm: levels start to rise before you wake up, to get you ready for the day ahead. This is called the ‘cortisol awakening response’ (CAR). It gradually decreases as the day progresses, so that by nighttime it is at its lowest, and you start to feel sleepy.

All still being well. Because with constant, unrelenting stress, things can start to go awry. Instead of gradually reducing throughout the day, cortisol remains high. This is a situation that can eventually take its toll on the HPA axis.

Initially, cortisol overstimulation can lead to high blood sugar, and everything that entails.

Constantly high blood sugar can turn into insulin insensitivity, meaning that the body’s cells no longer respond to insulin, and glucose remains high. This is a prediabetic stage. It’s also a vicious cycle stage, because many people, when stressed, have an increased appetite for all things sweet, possibly because of the reward factor offered by sugar. This means more blood sugar dysregulation.

‘Even in the absence of hunger, stress tends to precipitate the intake of calorie dense foods, fast food and food rich in sugar, especially in individuals with overweight or obesity.’

On top of all that, the combination of stress, cortisol and activation of the HPA axis increases abdominal, or visceral fat. In yet another vicious cycle, this fat acts as an endocrine organ that can increase production of cortisol.

Cortisol and dementia

High stress and prolonged cortisol production are linked to dementia, partly because they reduce sleep quality, a known risk factor for the disease.

When cortisol is high at night, when it should be low, it is associated with a smaller hippocampus, the main memory area of the brain. The hippocampus is particularly responsive to cortisol. High cortisol concentrations are seen in people with mild cognitive impairment (MCI), the pre-dementia stage.

‘…dysregulation of the HPA axis may occur at early (MCI) stage of AD (Alzheimer’s disease), possibly accelerating disease progression.’

Chronic activation of the HPA axis is also linked to:

• Hypertension

• Cardiovascular disease

• Gastrointestinal problems, including ulcerative colitis

• Disturbances to the gut microbiome

• Immune dysregulation

• Depression

• Anxiety

• Cognitive decline

• Bone loss

• Insomnia

• Weight gain

Worst of all, some might say, is premature aging. Yes, it’s true - too much cortisol makes you fat, sick and old before your time. The ageing effect occurs because too much cortisol suppresses another important adrenal steroid hormone, dehydroepiandrosterone, or DHEA.

DHEA is the hormone that keeps you young and slim, and although it decreases naturally with age, cortisol speeds up the process.

Further down the line…

Like most essential things, cortisol is required in just the right amounts: at the other end of the stress spectrum, depleted cortisol can also cause serious health problems.

The body’s capacity for adaptation has its limits, and if there is no let-up in the burden of mental trauma, cortisol eventually falls below normal. That is a concern because cortisol:

• Fights infection

• Maintains blood pressure

• Maintains blood sugar

• Blocks inflammation

• Stimulates tissue regeneration

• Stimulates the synthesis of collagen

At this stage, the adrenals are fatigued and you are no longer able to deal with stress. Your resistance has gone.

Mental and physical exhaustion ensue. Depression and brain fog follow suit. You are running on empty, and every day have a new mountain to climb. It can feel overwhelming, as well as exhausting.

‘Adrenal fatigue’ is not a medical condition, but the symptoms are real enough.

Chronic fatigue syndrome is associated with an under-functioning HPA axis. So too is fibromyalgia, a condition characterised by musculoskeletal pain and fatigue. People suffering from post-traumatic stress disorder have also been found to under-secrete cortisol.

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Cortisol ouput responds to stress, but it is also affected by diet. You can regulate your diet to regulate your cortisol, to help your body cope. You can also take a simple saliva test to establish if your cortisol is too high or too low, and at what time of the day dysregulation occurs.