Stress and Work Performance

A Corporate Nutrition article by London Nutritionist Sylvia Hensher

Stress: Friend or Foe?

Stress is a normal physical response to events that make you feel threatened or upset your balance in some way. When you sense danger – whether it’s real or imagined – the body’s defences kick into high gear in a rapid, automatic process known as the “fight-or-flight” reaction, or the stress response.

The stress response is the body’s way of protecting you. When working properly, it helps you stay focused, energetic, and alert. In emergency situations, stress can save your life – giving you extra strength to defend yourself, for example, or spurring you to slam on the brakes to avoid an accident.

The concept of job stress is often confused with challenge, but these concepts are not the same1. Challenge energises us psychologically and physically, and it motivates us to learn new skills and master our jobs. When a challenge is met, we feel relaxed and satisfied. Thus, challenge is an important ingredient for healthy and productive work.

However, beyond a certain point, stress stops being helpful and starts causing major damage to your health, your mood, your productivity, your relationships, and your quality of life.

Stress Warning Signs and Symptoms

  • Constant worrying
  • Inability to concentrate
  • Irritability or short temper
  • Feeling overwhelmed
  • Reduced energy
  • Depression or general unhappiness
  • Aches and pains
  • Diarrhoea or constipation
  • Chest pain, rapid heartbeat
  • Frequent colds
  • Eating more or less
  • Sleeping too much or too little
  • Using alcohol, cigarettes, or drugs to relax
  • Nervous habits (e.g. nail biting, pacing)

The Effect of Stress on Work Absenteeism

The national Labour Force Survey 2 reports that  in 2009/10 an estimated 435 000 working people in the UK suffered from stress caused or made worse by their current or past work, and an estimated 9.8 million working days were lost through work-related stress . On average, each person suffering from work-related stress took an estimated 22.6 days off in 2009/10.

Hidden Effects of Stress at Work:  Presenteeism

An increasing number of staff are suffering from “presenteeism” – when employees show up for work but are not productive because they feel stressed, sick, injured, or distracted3. These staff also risk infecting their colleagues with their illness, or de-motivating them by their attitude. Presenteeism is more prevalent than absenteeism and is tougher to identify and control. It has been shown to cost employers 2-3 times more than direct medical care.

Effects of Stress on Long-Term Health

  • Depression: stress is a major risk factor for depression. Studies have shown that depressed people are much more likely to have elevated levels of the stress hormone cortisol than people who are not depressed4.
  • Breast cancer: Studies have demonstrated links between chronic stress and breast cancer risk.
  • Heart disease: It is now well established that stress is a major cardiovascular risk factor. Stress increases homocysteine levels in the blood. Homocysteine is an amino acid produced by the body but many people lack the enzyme to break it down completely. Excess levels of the protein homocysteine can seriously damage the lining of the arteries and are a significant risk factor for cardiovascular disease5.
  • Memory decline: Studies have shown that chronic stress decreases short term memory and affects our ability to optimally regulate our body’s response to stress.6
  • Irritable Bowel Syndrome (IBS): Links have been identified between stress and the symptoms of IBS7.
  • Interrupted sleep: Disruption of the sleep-wake cycle is a common symptom of chronic stress. Normally, when you are asleep, levels of the stress hormone cortisol are low. But at times of chronic stress, cortisol levels may not drop sufficiently while you sleep, leading to insomnia.
  • Thyroid functioning: Chronic stress can have a dramatic effect on the function of the thyroid gland.
  • Immune function: Chronic and prolonged stress depresses the immune system. This is why people undergoing periods of chronic stress often suffer from more frequent infections8 .

Call us now on 0207 724 4445 /07812 163 324 or email us at to find out how we can help you, or your organisation, manage stress more effectively and boost performance through optimal nutrition!


1National Institute for Occupational Safety and Health (1999) Stress at work. Publication Number 99-101 last accessed online 27.7.2011 at

2Health and Safety Executive (2010) Statistics 2009-2010 last accessed online 26.7.2011 at

3 Harvard business Review (2004) Presenteeism: At Work—But Out of It last accessed 2.5.2011 at

4Swaab DF Bao AM Lucassen PJ (2005) The stress system in the human brain in depression and neurodegeneration. Ageing Res Rev 4 2 141-94

5Stoney C M (1999) Plasma homocysteine levels increase in women during psychological stress. Life Sci 64 25 2359-2365

6McEwen BS (1998) Protective and damaging effects of stress mediators. Effects of chronic stress on the brain. N Engl J Med 338 3 171-9

7Patacchioli et al(2001) Actual stress, psychopathology and salivary cortisol levels in the irritable bowel syndrome (IBS). J Endocrinol Invest 24 3 173-7

8Kiecolt-Glaser J. et al (1984) The enhancement of immune competence by relaxation and socialcontact. Paper presented at the annual meeting of the Society of Behavioural Medicine, Philadelphia (May 1984).

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