The physiology of stress

The effects of stress on your body chemistry, and how to address the problem. 

For most of us the term stress implies an emotional state experienced when, for example, work, family or friends are getting us down. Stress is actually much more than this and often less visible.

Stress is scientifically defined as physiological or psychological factors that cause healthy body functioning to be compromised. Included are physical factors such as food intolerances, inflammation, infection and nutritional deficiencies; as well as lifestyle factors such as smoking, too little exercise (or even too much exercise), too little sleep or too much alcohol.

All these stressors can fundamentally disrupt normal body functioning and biochemical processes, contributing to the development of mental illness.

Nutritional Deficiencies

One can live for years with susceptible genes and/or a nutrient deficient diet, with little, if any, negative effects. However, additional stress increases the nutrient demands on the body, resulting in the nervous system (or any of the body’s systems) no longer being able to function at its best. Therefore a seemingly minor stress trigger can bring about a sudden onset of mental illness. It becomes the straw that breaks the camel’s back.


One of the mechanisms by which stress contributes to mental illness, is by the faulty absorption of food, making essential nutrients unavailable for the production of neurotransmitters. Emotional stress puts the body in a state of ‘fight or flight’ where digestion and absorption is not the primary focus of the body.

Energy and nutrients are channelled away from these ‘unessential’ processes, towards the heart, lungs and limb muscles (for the genetically programmed and most likely not actual, flight). And so it is that chronic stress, highly prevalent in our society, can result in what amounts to a state of malnutrition.

Stress also increases the metabolic rate, resulting in increased nutritional and energy requirements. This makes for higher demands on our nutritional intake, increasing the need for nutrient-rich foods. Sadly, this is probably the time when we are unlikely to spend the time making a healthy meal; instead we often reach for nutritionally-deficient sugary refined foods – the chocolates, biscuits and slices of cake.

Adrenalin and noradrenalin

Another reason why stress contributes to mood disorders is that dopamine, the neurotransmitter whose functions include motivation and reward, is used by the body to make the hormones secreted in times of stress - adrenalin and noradrenalin. And so, when we are stressed, there is less dopamine around, meaning a decreased sense of satisfaction on completing tasks and so less motivation and drive to do them.

Cortisol is another stress hormone and one of its functions is to increase blood sugar levels, making energy available for flight. In most of today’s stress situations, flight is not required and so blood sugar levels shoot up. What shoots up, must shoot down, and low blood sugar often results in the so-called ‘blood sugar blues’.

High blood sugar levels also causes high insulin levels. Insulin is the body chemical which helps sugar enter cells, where it can be used for energy. However, insulin also encourages the deposit of fat around the middle (so-called visceral fat). These fat cells produce chemicals called cytokines, which are associated with many of the key symptoms of depression: social withdrawal, loss of interest in sex, changes in appetite, disrupted sleep patterns and increased anxiety.

Clinical depression

In fact, people suffering from clinical depression have been shown to have 40-50% higher concentrations of cytokines than people with a normal mood (although fat cells are not the only source of these chemicals). Cytokines are thought to promote inflammation in the brain, resulting in the development of mental illness.

Eating the right foods and taking the right supplements can help decrease this inflammation. The best foods are cruciferous vegetables (e.g. broccoli and cabbage), spices such as cumin and turmeric and those high in antioxidants and omega 3 fatty acids.

Prolonged exposure to cortisol can also cause increased growth of the amygdala, the portion of the brain that controls fear and other emotional responses. This contributes to a heightened expectation of environmental threats which could contribute to panic attacks and anxiety.

Lifestyle Factors

Lifestyle factors that have been shown to reduce stress hormones, contributing to decreasing and changing the body’s response to stress, include: yoga, massage therapy, mindfulness, meditation, walking, breathing, laughing, power naps, smelling roses or lavender (flowers or aromatherapy oils), or any other aromatic smells, listening to music, and bathing in Epsom salts. Epsom salts contain magnesium, which is a relaxant.

Role of Magnesium

Magnesium is required for more than 300 chemical processes in the body and is vital in the production of stress hormones. However, it is also necessary for the production of serotonin, the neurotransmitter which plays an important role in regulating moods and sleep.

When we hit the stress button, magnesium is taken away from making serotonin and given to the stress hormones, which can result in a serotonin level too low for the normal functioning of the brain. As a result depression and/or anxiety can develop.

Magnesium is almost universally deficient in the modern diet, which is low in magnesium-rich foods such as green leafy vegetables, wholegrains, nuts and seeds. It is also often deficient in soil which is fertilised as opposed to composted and removed in the refining processes of grains and sugar. So the bottom-line is: eat your greens; and better still, complement this with a magnesium supplement.


Herbs have been used for centuries to reduce the body’s response to stress. These include Rhodiola, Siberian ginseng, ashwagandha, Ginkgo biloba and ginger. They are known as adaptogens. However, be sure to contact a professional for advice when using herbs, as they may be natural, but they can have powerful effects.


Eating the right foods (and avoiding the wrong ones) helps our body manage stress. This goes a long way to creating and maintaining mental wellness. In addition to a healthy diet, I recommend that nutritional supplements are taken. It is important that a professional helps with deciding on the correct type and dose of such supplements, as this choice can often make the difference between getting better or staying sick.

(Beatrice Rabkin, Nutritional Therapist, Thrive magazine)

This article was first published in the launch issue of Thrive Magazine– Your Guide to Mental Wellness. Thrive is available for free from Pick n Pay Pharmacy or view online at  

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