Shift work is a reality for over 20% of the population in industrial countries across sectors such as transport, construction, healthcare and increasingly, retail and the service industries.
Just in the last year, several studies have added to the evidence base for the implications of working outside of our normal body clock programming. For those who employ shift workers, here is a round up of the key findings any responsible employer should be aware of:
1. We know more about how shift work affects our eating behaviour and diet quality.
A review paper published in May (1) examined studies of dietary habits in nurses since the year 2000 (there were 19!). They found that night work was associated with:
- Higher caffeine consumption
- Lower alcohol and fruit and veg consumption
- More frequent snacking, later meal timing of the last meal, eating at night, irregular timing
- And overall poorer diet quality
2. We’ve learnt that the best choice of meal during a night shift is a simple snack.
A study published by the University of South Australia in June this year (2) investigated the impact of different meal types during the nightshift on wellbeing, alertness and performance.
Comparing the impact of a snack, a meal or no food at all over a 7-day period, the research showed that while all participants felt fatigued and sleepy during the night shift, it is possible to lessen these effects by opting for a simple snack.
3. Certain findings on the impact of shift work patterns on alertness rang alarm bells with regards to safety implications
A study published in March (3) looked at alertness and performance across different shift patterns in health care workers. It highlighted ‘major negative implications on patient care and patient safety’ as well as significant economic and productivity costs. It also warned of an impact on driving safety whilst commuting to and from work.
These effects were mainly caused by disruption to the sleep-wake timing as well as sleep loss leading to sleepiness while on duty. There is a cumulative effect to sleep loss, which means accident and safety risks increase over the course of several night shifts.
It highlighted the importance of recovery time, which employers should plan into shift schedules. The European Working Time Directive has introduced the requirement for at least 11 hours of rest between shifts to allow sufficient time to commute to and from work and still provide adequate time for sleep.
4. There was additional evidence added to what we know already about an increased risk to cardiovascular and metabolic health.
A large Chinese study of more than 320,000 people (4) put the risk of developing coronary heart disease in shift workers at 13 percent higher compared to daytime workers. And for every year spent working on shift work, there was a nearly 1 percent increase in this risk.
Likely factors included disruptions to the sleep-wake cycle, increased stress, and unhealthy lifestyles often associated with shift work.
The researchers’ advice to employers is to focus on health promotion to make sure employees are well informed, and health checks to detect early signs.
Meanwhile another study (5) clarified some of the mechanisms involved in increasing the risk of heart disease and diabetes, explaining how shift work affects the way our body processes sugar and fat.
5. Finally, against a backdrop of increased awareness around mental health, studies in the last two years have highlighted the implications of shift work in this area.
According to recent estimates (6), around 10% of the US workforce experiences severe symptoms due to struggling to adapt to a night shift pattern. ‘Shift work disorder’ means poor or insufficient daytime sleep and excessive sleepiness on duty.
Beyond sleep disorders, a study from 2017 (7) revealed an alarming 42% increase of the risk of depression among those working night shifts.
What does this all mean for employers of shift workers?
There is no denying the impact of shift work on health, safety and performance. The good news is that many of the risk factors can be greatly reduced through lifestyle measures. The more we know about the facts, the more empowered employers can be to put in place measures that will go some way to countering these risks.
It’s an area we’ve been researching for some time at SuperWellness and we’re excited to be releasing some new nutrition and lifestyle packages specifically designed for shift workers in the autumn. Watch this space!
(1) Peplonska, B et al, The association between night shift work and nutrition patterns among nurses: a literature review. Med Pr. 2019 Jun 14;70(3):363-376. doi: 10.13075/mp.5893.00816. Epub 2019 May 14.
(2) Gupta, C et al, Subjective Hunger, Gastric Upset, and Sleepiness in Response to Altered Meal Timing during Simulated Shiftwork. Nutrients, 2019; 11 (6): 1352 DOI: 10.3390/nu11061352
(3) Ganesan, S et al, The Impact of Shift Work on Sleep, Alertness and Performance in Healthcare Workers, Nature. 15 March 2019 9:4635 | https://doi.org/10.1038/s41598-019-40914-x
(4) Cheng, M et al, Shift work and ischaemic heart disease: meta-analysis and dose–response relationship. Occupational Medicine, Volume 69, Issue 3, April 2019, Pages 182–188,https://doi.org/10.1093/occmed/kqz020
(5) Madhu, SV et al, Association of postprandial triglyceride responses with insulin resistance among rotational night shift healthcare workers. Experimental Physiology, 2019; DOI: 10.1113/EP087514
(6) Cheng, P et al, Shift Work Disorder. Neurol Clin 37 (2019) 563-577 https://doi.org/10.1016/j.ncl.2019.03.003