By Kyle Riley BSc (Hons).

Poor sleep, or more specifically, circadian alignment can contribute to many different health risks due to its impact on both the physiology of the individual and the lifestyle patterns they undertake as a consequence of irregular sleep habits.

The more significant problem with poor sleep hygiene has to do with biology. The body operates on a 24-hour cycle, or circadian rhythm, governed by the suprachiasmatic nucleus (SCN) that serves as both the ‘master clock’ and regulator of peripheral clocks, located in various organs around the body. The central and peripheral clocks work to ensure the body maintains alignment with the natural changes in daylight and darkness. It is this rhythm that tells us to wake when it is light and rest when it is dark and supports the many hormonal and physiological functions that need to occur in order to support the body throughout.

This disruption of the natural circadian cycle affects how the body functions and interferes with the natural release of hormones and other processes within the body, leading to potential problems of the cardiovascular system, metabolism, digestion, immune system, mental health and even fertility and pregnancy.

So given the importance of not only sleep but alignment with the natural 24-hour light/dark cycle, what does this mean for clients who find it difficult to change their sleep patterns due to shift-work?

In this scenario, much of the advice given is unrealistic and impossible to implement, leaving many health professionals feeling like they are unable to tackle any issues surrounding sleep. Instead they choose to ‘park’ such goals and focus on areas of lifestyle that are easier to control. Whilst this may be a valid short-term coaching strategy, there comes a point where sleep hygiene must be addressed, particularly as the health risks associated with prolonged shift work are actually quite alarming. 

In shift workers, research shows a 30-40% increase in risk of chronic diseases such as cardiovascular disease and type 2 diabetes and interestingly, the longer you do shift work, the higher your waist circumference and risk of obesity. In fact, 4 days of disrupted sleep due to shift work can push your physiology into a pre-diabetic state and one night of sleep under 4 hours can reduce immune function by 70%. Shift work is also correlated to inflammatory bowel disease, ulcerative colitis, lower energy levels and mental health conditions such as depression

So, aside from asking clients to give up their jobs, what else can we do as health professionals to support those who work shifts? We asked chrono-expert and PHA lead educator, Dr. Cam McDonald to share his top tips. 

1. Re-establish normal patterns of sleeping, eating and exercise as soon as possible after night shifts are over

The body likes to follow predictable patterns in alignment with the 24-hour circadian rhythm. The more you mismatch daily lifestyle habits with this rhythm, the more stress it creates on the body. Once a period of working shifts is complete, supporting your clients to quickly establish a routine of eating, working out and sleeping in alignment with the natural light-dark cycle should be of highest priority. 

2. During shifts, minimize food intake throughout the evening, focus on low/non-caloric fluids and aim to have all meals through the daylight hours. Try to keep your meal timings on a consistent pattern.

Much of the metabolic risk of shift-work comes from the irregularity in meal timings and quality of food. Put simply, the body likes to keep processes on a consistent rhythm and is not designed to digest large meals in the middle of the night. Here you can support your client by helping them to establish a consistent pattern around meal times each day, and ensuring they find easy to digest, low calorie meals such as soups or broths to consume during the night, keeping the consumption of main meals to the daylight hours.

3. Aim to use light movement, warm drinks, healthy crunchy snacks as ways of staying awake to reduce caffeine consumption as much as possible overnight.

Many shift workers use caffeine to give them more energy during the night. As previously mentioned, the body should be resting during this time and is already under a level of stress from being awake and at work. Using caffeine to get through the shift will only add more fuel to the fire through the release of stress hormones. Support your clients to find alternative ways to help them during the shift that do not involve the use of caffeine or other stimulants. Warm caffeine-free herbal teas can support alertness without the added stress and healthy foods that provide a crunch can help to increase alertness naturally. 

4. Support ‘morning sleep hygiene’ 

Improving overall sleep quality, regardless of the time you go to bed, will still be one of the most impactful things you can do to reduce the negative effects of shift-work. Here are some additional tips to support quality of sleep during the daylight hours.

• Create a ‘morning’ bedtime routine to prep the body for sleep
• Have a hot bath, practice meditation, breathing techniques, or stretch to calming music
• Use block out blinds or curtains in the bedroom with dark shades or a sleep mask
• Limit the use of electronics before falling asleep
• Wear blue light blocking glasses during work, on the way home from work and around the house before bedtime
• Consider using a white noise machine to block out any daytime noise that may affect the quality of your sleep

As you can see, all is not lost for those who work shifts. There are many strategies we can look to implement to offset some of the negative effects of circadian stress. If you would like to learn more about sleep, circadian rhythms and the practical application of chronobiology, check out this free webinar from Dr. Cam Mcdonald here.

References

Shift-Work Morbidity and Mortality

CVD – https://www.ncbi.nlm.nih.gov/pubmed/29929393

CVD – https://www.ncbi.nlm.nih.gov/pubmed/29247501

CAD – https://www.karger.com/Article/FullText/481088

Clock genes and cancer – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5410358/

Mental health – https://www.nature.com/articles/ncomms10889

Desynchrony and it’s effects 

https://www.sciencedirect.com/science/article/pii/S105381191300921X

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654533/