14 DAY TRIAL // Canadian researchers at the Queen’s University in Kingston, Ontario, discovered during a new study that modern-day work shifts are not as disruptive to human health as other types of shifts that existed decades or centuries ago. In other words, current work schedules are more humane.
The team also found that the way in which shifts are distributed nowadays has less of a carcinogenic effect on the human body than it used to. In past days, workers could be stuck in factors for up to 16 hours a day, pulling extreme shifts for low pay and in miserable conditions.
Another problem that used to exist in the past was high level of disruption each worker felt on their circadian rhythms, the natural clocks in their bodies that regulate the way organs respond to the night-day cycles. Working at night usually disrupts this system.
Certain chemicals, for example, are only released in the body during the evening, as we prepare to go to bed. Our performance levels decrease, and our mind is set on the idea that rest is coming. However, for some people, this is the time of day when they are expected to be the most active.
“Recent research has suggested shift work could increase the risk of cancer, although the biological mechanism responsible for this observation is still unknown,” explains the lead author of the new paper, Queen's University PhD candidate Anne Grundy.
“Our study indicates that the now common rotating shift pattern of day-day-night-night may not disrupt circadian rhythm or melatonin production significantly,” she adds, referring to a protective hormone our bodies naturally produces. This chemical has tumor-suppressing abilities.
Details of the new research effort were published in a recent online issue of the medical journal Cancer Epidemiology, Biomarkers and Prevention, PsychCentral reports.
According to past studies, melatonin levels spike and reach maximum production from 00.00 am to 4am, which means that workers subjected to light during those critical moments may be at an increased risk of developing various forms of cancer.
“We’ve already seen a shift away from the older patterns of two weeks of days, two weeks of nights, and a short time off to more humane patterns of day-day-night-night then five days off, so it’s possible that an intervention to combat the health risks of shift work has already occurred,” Grundy explains.
She adds that the new investigation was carried out on Kingston General Hospital (KGH) shift workers, who pull various types of shifts to fill their quotas. A number of 123 women were investigated.
“The overall change in melatonin levels that we found may still be a concern. We look forward to seeing other studies that either confirm our findings or that examine the impact of specific risk factors like extreme shift patterns and higher intensities of light at night,” the team leader concludes.