How harmful is shift work?
The stress of shiftwork also can aggravate health conditions, such as heart disease or digestive disorders. How do these hazards occur? Working at night makes it difficult to get enough sleep. Sleep after night work usually is shorter and less refreshing or satisfying than sleep during the normal nighttime hours.
Shift work disrupts the circadian rhythm -- our internal body clock that is keyed to natural daylight and darkness. Because circadian rhythm affects how the body functions, disrupting it can throw everything out of whack -- including our cardiovascular system, metabolism, digestion, immune system, and hormonal balance.
It can also be stressful for the family to have to adapt its activities to the shift plan of the working family member. This can result in a diminution of quality of life, problems in partnerships, and – in the worst case – to social isolation.
Shift work is known to decrease potential lifespan by 10 years. As such, those who opt to do shift work in order to increase their wage-earning capacity, often lose the benefit when they retire.
Shift work is linked to poorer working memory and slower mental processing speed, according to Austrian researchers, who warned it may heighten the risk of workplace injuries and errors.
It takes about 10 days for the body to adjust to night shift work. However, it is common for night shift workers to revert to daytime routines for a day or two during days off, which tends to make the circadian rhythm unstable.
Findings In a large cohort study of 46 318 female nurses, long-term rotating night shift work was associated with modestly decreased odds of healthy aging after 24 years of follow-up.
Shift workers – those who may work long hours, overnight, or with irregular rest periods in between work – are subject to this, which could be why they appear to be at higher risk for obesity, diabetes, and metabolic diseases including having a liver that retains more fat.
The International Agency for Research into Cancer (IARC) has classified night shift work as category 2A (probable carcinogen).
Shift workers are also at a higher risk for serious diseases. These shift workers have a 23% higher risk for heart attacks, a 5% higher risk for strokes, and a 24% higher risk for all cardiovascular diseases combined. There is also evidence to support that shift workers lose cognitive function over time.
Is rotating shift work unhealthy?
Rotating night shift work has previously been linked to chronic diseases, including cardiovascular disease,7,9,10,52 diabetes,6,54 cancers,17,18,55,56 and mental health,13,57 with limited evidence for cognitive function.
They estimated that 10 years of shift work had the effect of ageing the brain by an extra 6.5 years, based on the results of the cognitive tests. They also concluded that it took five years to recover that level of function after stopping shift work. So is the “graveyard shift” really killing our brain cells?
The typical healthy work week consists of 40 hours or less (A 38-hour week is optimal according to a study by time management expert Laura Vanderkam as relayed by Atlassian), a consistent schedule, and an array of workplace systems that set employees up for success.
Irregular hours of work and work patterns that include night and early morning shifts can lead to disruption of the internal body clock, sleeping difficulties and fatigue.