The night shift, the dog watch, the graveyard shift; whatever you call it, work well past sunset has become a staple of working life. With it come the annoyances of working during hours we would rather be sleeping through: the hours seem to merge, the eerie silence accompanying the night, and so on. But besides these complaints are there any serious health issues of working so late: can the graveyard shift land you in a grave?
A primary consequence of night shifts is that it alters a person’s circadian rhythm. The circadian rhythm is essentially the body’s daily internal clock that regulates when certain processes occur. This change in the rhythm is what causes many of the initial problems associated with night shifts, which in turn lead to several long term concerns. The most common issue people tend to state are disturbances in their sleep cycles. The disruption of the body’s clock can result in insomnia. Professor J.M Harrington (from the institute of occupational health at the University of Birmingham) reported shift work, especially night work, to be a major cause of sleep loss. The issue is not just the hours of sleep lost, but also the quality of sleep lost. Rapid eye movement (REM) is a crucial phase in the sleep cycle. It is during this period where the body undertakes fundamental mechanisms such as repair. Those who regularly carry out night shifts have been found to have a decrease in REM sleep.
Another short term issue frequently brought on by night shifts are gastrointestinal issues, including constipation, heart burn and feeling bloated. This is due to a person seeking high calorie foods to combat being tired, forcing the body to go into digestion mode. This conflicts with the circadian rhythm as organs such as the liver would normally use this time to clear out harmful or toxic products from the body. Prolonged, this is thought to lead to long term problems such as obesity (due high calorie foods being high in saturated fat), and diabetes (as found by a Japanese study, noting that people who worked sixteen hour shifts had a 50% greater incidence of developing diabetes compared to those who only worked the day shift).
Further issues are raised by a study conducted in 2007 which followed 700 health workers over four years. The study found that those who worked night shifts had an incidence of metabolic syndrome three times higher than their daytime working counterpart. Metabolic syndrome includes a combination of high blood pressure, high blood sugar and unhealthy levels of cholesterol. These are risk factors for diabetes as well as various heart conditions. Studies have also shown that night shifts appear to increase the chance of developing cardiovascular disease by up to 40%. The risk of stroke for long term shift workers (those having done so for at least 15 years) also increases by 5% for every five years further.
The problems of night shifts are not restricted to physical problems, but mental also. Night shifts have a profound effect on the ability of a person to concentrate. This can result in an increased risk of accidents or injuries. Furthermore, many workers show signs of depression. This is again most likely linked to alterations in body chemistry following changes to their circadian rhythm. This idea is supported by a study conducted in 2007 which found night shift workers had lower levels of serotonin, which is an important chemical in mood regulation.
To conclude, throughout this article we have seen multiple ways that working a night shift can affect a person’s health both physically and mentally. So can the graveyard shift kill you? Perhaps sustained over a long time, but what should be noted is that most studies deal with correlations, which are used to imply causation. To come to a true conclusion further research has to be done and with night shifts not disappearing anytime soon, we’re just going to have to risk it.