English
The Risks of Shift Work
Posted on Jul 28, 2014 by Ruth Loftus
There was a time when just going to work was quite a dangerous activity with all sorts of risks to one’s health in the workplace. Although that is still the case in some parts of the world, in the developed West where large numbers of us spend the working day in offices, the workplace has become a much safer environment. Even in factories, the focus has been on improvements to the health and safety of employees, so these are now much safer places than they ever used to be. However, research is now suggesting a significant threat to health is arising not from where we work - but when. Specifically, it seems that people who regularly work night shifts are more likely to fall victim to a range of conditions ranging from heart disease and strokes to diabetes.
The latest research suggests that disrupted sleep patterns might be a consequence of shift work and that this can have quite profound effect on the body’s chemistry. Investigations have shown that some 5% of the body’s genes are actually tuned to be active at certain times of the day. Disruption to sleep patterns throws this precise timing out and can lead to different organs – brain, heart, liver for example – operating at different rhythms. Imagine a group of soldiers each marching to their own individual beat and the confusion and chaos that would arise – this time disruption can have a similar chaotic effect on the body and its processes.
The scale of disruption was a surprise to researchers and although these initial results have been taken from a fairly small study, they may begin to explain some of the more specific health problems that have been associated with shift work for some time. Work undertaken in Canada and Norway has indicated that regular shift work is associated with a rise in heart attacks and coronary attacks and up to a 5% increase in the incidence of strokes. However, as yet there is no significant association between shift work and fatality from these illnesses.
There is also a suggestion that in addition to unhealthy sleeping patterns, shift workers may also have poorer dietary habits. Their living style in effect means that their nervous system experiences a perpetual level of activity which has its own impact on the likelihood of obesity and on cholesterol levels.
A programme of laboratory based experiments in strictly controlled environment has highlighted the way in which sleep disruption may bring about diabetes. Again, this has implications for risks that might be faced by shift workers. The programme of broken sleep imposed by the research team resulted in significantly raised sugar levels in the blood as a result of lower levels of insulin production. After eating their meals, some of the participants had sugar levels at a level that they could be classified as "pre-diabetic". Participants also risked putting on weight as the body slowed down with a lower metabolism. Given this was a laboratory experiment under very specific conditions, applying its conclusions to the ‘real world’ needs to be done some with some caution, but the researchers themselves did feel that their work highlighted an elevated level of risk to shift workers and others whose work or lifestyle results in sleep disruption.
Oil rigs are already reputed to be one of the most dangerous and risky physical work environments. The shift patterns for oil rig workers add further possible health risks with evidence that riggers may be more liable to heart attacks as a result of the stresses of shift work - and split shirt working in particular. In research, workers who had a work pattern of seven night shifts followed by seven day shifts showed unusual levels of melatonin, a hormone which is produced at night and regulates sleep. For the old riggers, the hormone levels did not become aligned to new sleep times following shift changes. In addition, the riggers had higher levels of fatty acids in their blood after meals, suggesting they were at higher risk of heart disease, diabetes and other metabolic disorders.
For those who cannot avoid some shift work, the advice is – if possible - to avoid permanent night shifts, work shifts of more than 12 hours and try to ensure that they have two full nights' sleep between day and night shifts. These simple, practical solutions can help people to cope with shift work without undue repercussions. Regular monitoring of blood pressure and cholesterol are recommended as well as keeping an additional eye on weight levels as controlling these factors can make a big difference to general health.