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If you ’ re doing a night shift , everything in your body is telling you that it ’ s time to go to sleep but you ’ re giving it mixed biological signals .
Are night shifts killing us ?
University study confirms the harm night shifts can do to our health .
By Conor Burke
According to researchers , our bodies are straight up not designed to be going at night and the disruption to our natural circadian rhythm may well result in cardio-metabolic disease .
A team at Charles Sturt University looked at a group of healthy males and split them into two groups : shift workers and non-shift workers .
They did pre-screening questionnaires to do with their general health and screened for existing disorders pre-trial , from diabetes to pre-existing arrhythmias or cardiovascular conditions .
“ What we found is that shift workers , even apparently healthy shift workers , did have increased risk markers for future cardiometabolic conditions ,” said researcher and PhD candidate Blake Collins . Collins tested people during work using things such as a glucose tolerance test .
“ Basically you drink a specific amount of a sugary drink and then over a two hour time course we see how quickly the body metabolises or removes that glucose , and if you ’ re taking longer to metabolise that glucose it ’ s a risk factor for type 2 diabetes ,” he tells Campus Review .
“ We also looked at things like their cardiorespiratory fitness , current things like kidney levels , those kinds of generic markers of health as well , and that ’ s what we found — shift workers had increased risk markers for future disease states .”
Approximately 1.4 million people work shift work in Australia , making up 16 per cent of all employees . Around 46 per cent of nurses worked a rotating shift in 2015 .
Collins says that there could be a few reasons why shift work doesn ’ t agree with the human body .
First , access to healthy food can be difficult late at night and he says that shift workers are also more likely to smoke or engage in similar unhealthy behaviours .
But equally , the body ’ s natural 24 hour rhythms struggle to adapt to night shifts .
“ Your heart rate , blood pressure , those kinds of things are all on this rhythm and it ’ s regulated by cues , and those cues are for exposure to light , when you eat something and when you ’ re physically active . So , those three factors train the body into that 24 hour rhythm and that ’ s Is your night shift killing you ? what helps control our normal function ,” Collins says .
If you ’ re doing a night shift , everything in your body is telling you that it ’ s time to go to sleep but you ’ re giving it mixed biological signals .
“ You ’ ve got an artificial light on , you ’ re being physically active , all these things that are basically sending these mixed biological signals to the body which we ’ ve seen can acutely affect cardiometabolic health ,” Collins says .
Another area of work Collins and his team are looking at is whether acute bouts of exercise could balance the negative effects of shift work .
“ If you exercise before a shift , then we know that the shift is going to affect , say , your insulin sensitivity negatively , but exercise positively affects your insulin sensitivity .
“ So , was it the case that we could acutely do some things to offset those negatives ? And then if that becomes chronic , we could encourage all of our shift workers to exercise , then that would potentially offset the negative effects of doing shift work .”
Exercise has been shown to increase attention and decrease fatigue , Collins says , so if you are doing a 12-hour night shift and fatigue is setting in , a short hit of cardio might be a useful intervention .
Collins ’ research looked at males largely because of the businesses he had access to in Bathurst , such as prisons and mines , but a future area of research would include female participants and a hospital setting would throw up a lot of interesting questions as to the best way to combat the negative effects of night shifts .
“ So , does it matter if you do clockwise rotating shifts ? So , should you go from a morning to an afternoon to a night . Go anti-clockwise ?” Collins wonders .
“ The length of the shift is another one . Is it more beneficial to do shorter shifts ?
“ Some people prefer to do a couple of 12 hour shifts since even though it ’ s a longer disruption , you have to do less shifts . Whereas if you do eight hour night shifts , you ’ d have to do an extra night in that rotation to work the same hours .” ■
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