health effects of shift work

Today I will be talking about the health effects of shift work.  Working outside of the regular 9 am-5 pm hours has become a norm of modern living.  However, shift work goes against our biological desire to be awake during the day and asleep at night.  I’ve always understood that shift work wasn’t great for your health.  You always hear things like “Shift work takes years off your life”.  However, it wasn’t until I did some research that I truly understood the impact shift work has on our health, and how important taking steps to support your long-term health is.

The most immediate effects of shift work include; increased fatigue and sleepiness, impaired cognition and impaired alertness.  This affects reaction time, decision making, information processing and attention, and leads to an increased risk of errors, accidents and injuries.  People often misjudge their own sleepiness, believing that they are alert and capable of making good decisions, when in fact their judgment is impaired.  Research suggests that the effects of one night shift may cause greater impairment than having a blood alcohol reading of 0.05%.  Yikes!  The only shift I drove to work for was night shift, that’s a scary thought!  This explains why shift workers are at an increased risk of car crashes and near-misses when driving home from work.

Long-term health effects of shift work and sleep disturbance include:

  • Weight gain – especially around the middle.  Weight gain occurs due to several reasons.  The way your body processes and metabolises food is linked to the circadian rhythm.  Overnight the gastrointestinal system and the metabolism of energy and glucose slows down, increasing the risk of your body storing foods eaten overnight as fat.  Also, sleep deprivation affects the foods we eat, often results in cravings for high fat and high sugar foods. When we are tired and stressed we seek out fast, convenient options such as takeaway.  We tend to grab foods that are lacking the nutrients our body needs.
  • Heart disease – Hypertension, stroke, heart attack.  An increased risk of cardiovascular disease (CVD) is thought to be due to the metabolic and hormonal changes that occur with an altered circadian rhythm.  These changes may cause high blood pressure and high blood lipids, two risk factors for developing CVD.  Other risk factors for CVD common in shift workers are – high stress, poor diet and increased cigarette smoking.
  • Type 2 diabetes – At night the body doesn’t process and metabolise blood glucose to the same extent as it does during the day.  At night there is an increase in insulin resistance and reduced glucose tolerance, increasing shift workers risk for type 2 diabetes.  This is made worse by poor food choices and weight gain that occurs for many shift workers.


You have a higher risk of developing health issues the longer you do shift work for.


  • Gastrointestinal problems – Especially constipation and stomach discomfort.  The digestive system is linked to the circadian rhythm, with digestive function slowing down overnight.  This affects the bodies ability to digest and metabolise foods eaten overnight.  Shift workers also tend to eat a less healthy diet, which is often low in fibre and high in refined sugar and caffeine.  This affects the health of the digestive system, including the gut microbiome.  To find out more about gut health have a read of my blog ‘What is Gut Health?
  • Mental health conditions such as depression and anxiety.  Mental health conditions may occur due to the sleep disturbances that occur with shift work affecting the serotonin and cortisol levels.  And also because irregular hours affects ones social connections, and increases stress levels.
  • Increased stress.  Shift work increases the production of cortisol, the body’s stress hormone.  Cortisol also increases our desire for sweet sugary foods to provide more glucose to help fuel our ‘fight or flight’ response.  Additionally, stress and cortisol add to our risk of developing type 2 diabetes.  To read more about stress, check out my blog ‘What is Stress?
  • Certain cancers – Breast, bowel, prostate.
  • Other conditions associated with shift work – increased infections, menstrual problems, back pain, headaches and migraines, sleep apnoea


flow chart of the effects of shift work on health


As you can see, most of the conditions associated with shift work occur due to a disruption to the circadian rhythm, which in turn affects the biological processes occurring within our bodies.  Therefore, it is super important for shift workers to address any sleep disturbance or issues that have arisen from doing shift work and to support their long-term health.

How can naturopathy help?

We look at things through a holistic lens.  For example, if you are having trouble sleeping, why?  Is it just that working at night goes against your body’s natural desire to sleep at night?  Or is something else playing into this?  Your diet? Stress? Worry? Lifestyle choices?  We can improve sleep quality using medicinal herbs, nutritional supplements, by examining and making changes to your diet and by providing lifestyle advice, such as ways to prepare your bedroom for sleeping.

Other areas naturopaths help with include:

  • Improving energy levels
  • Improving gastrointestinal health
  • Providing dietary advice to reduce the risk of cravings, weight gain and insulin resistance
  • Reducing stress, anxiety and improving mood
  • Helping boost immune function – shift worker often get colds and flu and hay fever
  • Help prevent burnout

What next?

If you’d like my help, have a look at my website  I offer both in-person and online appointments from my clinic in Caloundra.  I also have a free 15min discovery call which allows you to have a chat with me to learn more about naturopathy and how I might help you.  Thanks!!  Take care, Annie.


Behrens, T., Burek, K., Pallapies, D., Kosters, L., Lehnert, M., Beine, A., Wichert, K., Kantermann, C., Bruning, T. & Rabstein, S. (2019). Decreased psychomotor vigilance of female shift workers after working night shifts. PLoS ONE, 14(7), e0219087.

Dibner, C. (2018). The importance of being rhythmic: Living in harmony with your body clocks. Acta Physiologica, 228(1), 13281.

Wang, X., Armstrong, M., Cairns, B., Key, T. & Travis, R. (2011). Shift work and chronic disease: the epidemiological evidence. Occupational Medicine, 61, 78–89. DOI:10.1093/occmed/kqr001

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