What do you think of when you hear the word “stress”? Is it the thought of being in a dangerous situation or the many demands and pressures of your everyday life?

For most people it’s the latter. Our 21st century world is full of deadlines, pressure to be “on call” all the time and unrealistic expectations to be able to achieve in all areas of life. It’s no wonder that many people report high levels of stress.

To stay healthy it’s vitally important that we acknowledge and understand the effect all this stress is having on our bodies. In this blog we’ll explain how and why stress affects us physically, and hopefully give you some food for thought as to how to reduce your overall stress load.

Human evolution and the acute stress response

The human body has evolved to be able to cope with a certain amount and type of stress. For most of history, humans have been hunter-gatherers, and it can be helpful to understand the human stress response in the context of stresses that a hunter-gatherer might have been exposed to.

Hunter-gatherers would have needed to be able to respond very quickly and effectively to acute dangers, such as being chased by a predator. Then they would either escape or be eaten and the stressful time would be over. Afterwards, they would have a quieter time spent socialising, eating and drinking, and sleeping. Humans therefore evolved the “fight or flight” and “rest and digest” responses to deal with what is known as acute stress.

We activate the fight or flight response when our brains perceive danger, such as when a predator or threat is spotted. The adrenal glands, which sit on top of the kidneys, release adrenaline and noradrenaline within a split second. Adrenaline and noradrenaline are both neurotransmitters (brain chemicals) and hormones. They make our heart beat faster, raise our blood pressure and dilate the bronchi in the lungs so that we can supply more oxygen to our muscles in order to get away from the danger. Our pupils dilate so that we can see where we’re running to.

Chronic stress

If the stress continues, we start to release a longer acting stress hormone called cortisol. This causes our blood sugar to rise by releasing sugar from storage sites in the liver to give us fast energy. It can also break down fats and proteins for energy. When stress last for a long period of time, known as chronic stress, the whole communication system between the brain and the adrenal glands (which release the stress hormones) can become dysfunctional, resulting in impaired responses to stress.

During the emergency situation of fight or flight, the body will not waste any of its precious resources on digestion or immunity, so blood flow to the digestive system is reduced and immune function is impaired. This all makes sense when running away from a predator, but it’s not so effective if our stress is due to rising fuel costs or having to write a report by 3pm on Friday. We don’t physically run away from these problems to use up all the glucose that has been released into the bloodstream, and unfortunately these types of stresses do not resolve so quickly.

By contrast, when the rest and digest response is activated, saliva and digestive juices are stimulated and the body has resources to devote to immunity, repair and reproductive health.

Note that both these responses are healthy evolutionary adaptations to the demands of life. What has changed in our modern world is that we spend much longer in the fight or flight response than we evolved to, and much less time in the rest and digest response.

A note on healthy cortisol

Although the term “stress hormone” may sound negative, it’s important to note that we do need a certain amount of cortisol in order to function well. If we didn’t have enough cortisol, we wouldn’t be able to get out of bed in the morning.

Healthy cortisol secretion follows a daily rhythm, with the highest levels when we wake up in the morning, and lower levels as the day goes on, dropping to a low in the evening to enable us to fall asleep.

Chronic stress today

Thinking of the physiological effects of the stress hormones, it should come as no surprise that the consequences of being in the fight or flight response chronically can be:

  • High blood sugar, contributing to the epidemic of prediabetes and diabetes
  • High blood pressure, leading to a higher risk of cardiovascular disease
  • Low or dysregulated immunity, leading to frequent illness and autoimmune disease
  • Impaired digestion, often leading to bloating and discomfort
  • Disrupted circadian rhythm, leading to tiredness and insomnia
  • Imbalanced sex hormones, leading to menstrual problems and difficult transitions through menopause for women and potentially infertility in men.

You can begin to see how far-reaching the impact of stress on the body is.

Allostatic load

Perceived threat is not the only factor that can activate the stress response. The same fight or flight cascade of neurotransmitters and hormones can be triggered by lifestyle and diet, such as:

  • large fluctuations in blood sugar
  • nutrient deficiencies
  • infections, the presence of toxins
  • caffeine
  • obesity
  • extreme heat or cold
  • too little or too much exercise

It is only by addressing all the factors that may be contributing to our stress that we can start to make progress. Thinking about, or even drawing, our stress bucket can be helpful….

The stress bucket

Your ability to cope with stress is like a bucket. Mental, emotional and physical stresses each contribute to the water in the bucket. Taken individually, our body may be able to adapt to each stress. However, the effects are cumulative, and when faced with many different stressors the body may not be able to adapt and the bucket overflows. This is when ill health can result. Means of dealing healthily with stress – spending time in nature, talking with friends, meditating, practising yoga etc – open a tap on the bucket to release the water safely.
If we keep this analogy in mind, it becomes easier for us to support ourselves in times of difficulty. For example, if you are going through a very stressful time emotionally, it may not be a good time to train for a marathon, because the combined stress might push your body too far.

Nutrition to support times of stress

The food that we eat can have a huge influence on the physical stresses going on in the body, and can also support the health of our brain and adrenal glands which regulate our stress response.

To minimise physical stressors:

  • Keep your blood sugar stable: avoid sugars and white carbohydrates, and eat high protein food and plenty of vegetables with every meal
  • Avoid toxins in your food: minimise or avoid alcohol, and consider choosing organic products when you can, especially for animal products
  • Avoid foods to which you are intolerant. Keep a food diary to monitor your response to different foods.
  • Drink caffeine in moderate amounts only, or cut it out completely. Read our blog Coffee: Is it Good or Bad?
  • Maintain a healthy body weight
  • Eat an anti-inflammatory diet: enjoy a rainbow of vegetables and fruit, plenty of herbs and spices, oily fish, wholegrains such as oats, quinoa, brown rice, legumes, and nuts and seeds. Top tips are on our blog Winter Fibre.

Specific nutrients also support the health of your brain and adrenal glands.

Potassium can be obtained by eating a diet rich in fruits and vegetables

Magnesium calms some of the physiological effects of chronic stress, but is depleted in times of stress. It can be found in green leafy vegetables, legumes, nuts and seeds, and wholegrains.

Omega 3 fatty acids, which are found in oily fish, walnuts, chia and flaxseeds, blunt the fight or flight response. Because these fats can interact with molecules within our brain, they can also help our brain to cope with stress.

The group of B vitamins help us to cope with stress, and are obtained from a whole food diet. Vegetarians and vegans may need to supplement vitamin B12. Please seek professional advice before taking nutritional supplements, particularly if you are on prescribed medication.

There are many more strategies that can help you to cope with stress, and if you are interested in our talk, either in person or on-line, Improve your Resilience to Stress with Nutrition please call us on 07966 478974.

Our thanks to Joan Faria of Empowered Nutrition for contributing this blog.

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