Arriving home sometimes just before 8am, as I begin my day, he goes to bed and emerges in the early afternoon. If the neighbours are redecorating (which they often do) then this can make for a pretty broken rest.
At least now his night shifts are only occasional, but after so many years, we do often wonder how this could be affecting his health.
So what do we know about the health risks of shift work?
We humans are a diurnal species, which means that we are designed to be active during the day. We have less of an appetite at night, when our body is actually supposed to fast and focus on repairing and restoring itself.
Our blood sugars are regulated differently at different times. At night, growth hormone, released during the first deep-sleep phase, and the stress hormone cortisol summon blood glucose from our existing reserves (mainly in the liver). This allows our central nervous system to keep functioning, without the need from external fuel. Our muscle cells are not supposed to need the energy at that time, so they are not that receptive to insulin (which normally allows them to take in glucose).
This could be one of the reasons why night workers so often suffer with glucose intolerance, gaining weight around the middle and more frequently than average developing conditions such as diabetes. One study showed that just three nights of disrupted sleep decreased insulin sensitivity by 30%, even with the same number of hours.
During the day we tend to run on glucose, and store fat, and then at night, when we should be fasting, our metabolism becomes more efficient at burning fat. This might explain why eating at night can increase the levels of triglycerides in the blood, and fat storage generally.
Even after two years of regular night work, studies have shown that glucose and insulin rhythms are only partially adjusted to night work.
Digestive health can be another issue, with problems such as IBS or peptic ulcers more frequent for night shift workers. Our digestive system is meant to be at rest during the night, and the hormones that regulate hunger and satiety work differently too.
Homocysteine, an amino acid associated with an increased risk of coronary heart disease, has been shown to be higher in night shift workers. This chemical is at its highest during the night, and is further increased when you eat meat.
Add to this the problems I mentioned earlier, linked to insulin resistance, including fat deposited around the organs and on the waist, having an inflammatory effect in the body, along with higher levels of blood triglycerides, and it’s no wonder that cardiovascular risk is higher in night shift workers.
Ping goes the microwave timer…
So what can you do to minimise the health risks?
If you work night shifts yourself, or if you employ teams of shift workers, there are some useful tips that can benefit you and your employees:
- Stick as closely as possible to a normal day and night pattern of food intake
- Aim for three satisfying meals across a 24 hour period
- It’s best to avoid or minimise eating between midnight and 6am and try to eat at the beginning and end of the shift
- Avoid large meals for 1-2 hours prior to sleep
- Eat breakfast before day sleep to avoid waking due to hunger
- Choose whole foods, vegetables, lean protein, eggs, nuts, antioxidant rich food and drink such as red bush tea
- Avoid sugar rich products such as soft drinks, bakery items, sweets and non-fibre carb foods (high GI) like white bread
- Avoid foods that are high in iron at night (such as red meat) as they can disrupt the liver’s circadian rhythm and cause it to be out of synch, enhancing glucose metabolism problems
- Maintain a healthy lifestyle with exercise, regular meal times and good sleep hygiene outside of work
- Get vitamin D levels checked regularly as working nights can mean reduced exposure to daylight. Vitamin D deficiency is extremely widespread, and linked to a vast range of health risks, including a number of cancers.
- Get yearly blood tests such as fasting glucose, to detect any risk of diabetes before it occurs
- Design shift schedules so as to allow adequate time between shifts for sleep, meal preparation, exercise, family time
- If possible provide a relaxed and sociable eating area. Eating in a relaxed environment will help stimulate a state of ‘rest and digest’ that’s more conducive to good digestion and absorption of nutrients
- Aim to provide a variety of good quality food staff on-site: whole foods and high quality snacks
A light box can come in handy (especially those used for SAD – Seasonal Affective Disorder)! A recent study showed that exposure to bright light before driving home can help improve alertness, as it suppresses melatonin.
Want to find out more?
At last! The top nutrition tips to stay healthy when working shifts.. all on one side of A4
- A summary of the latest research into health and circadian rhythms providing you with the accurate information you need
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- Arne Lowden, Eating and shift work – effects on habits, metabolism, and performance, Scand J Work Environ Health. 2010; 36(2): 150 – 162
- Fangyi Gu MD, Total and Cause-Specific Mortality of U.S. Nurses Working Rotating Night Shifts, American Journal of Preventive Medicine, March 2015 DOI: 10.1016/j.amepre.2014.10.018
- Marjory L. Givens, Shiftwork, sleep habits, and metabolic disparities: results from the Survey of the Health of Wisconsin. Sleep Health, 2015; DOI:10.1016/j.sleh.2015.04.014
- J.-C. Marquie, Chronic effects of shift work on cognition: findings from the VISAT longitudinal study.Occupational and Environmental Medicine, 2014; DOI: 10.1136/oemed-2013-101993
- Gan, Shift work and diabetes mellitus: a meta-analysis of observational studies.Occupational and Environmental Medicine, 2014; DOI:10.1136/oemed-2014-102150
- Judith A. Simcox, Dietary Iron Controls Circadian Hepatic Glucose Metabolism through Heme Synthesis. Diabetes, October 2014 DOI: 10.2337/db14-0646 1939-327X
- American Academy of Sleep Medicine, Bright light after night shift may enhance alertness and cognitive performance: Using bright lights may be particularly effective for low light work environments. commutes that occur before dawn. June 2015