But these findings are almost always in people who do shift work—bouncing back and forth between nights and days. There’s even something called Shift Work Sleep Disorder (or Shift Work Disorder), defined by increased accidents, work-related errors, irritability, or mood problems.
The more we learn about sleep, the more we learn the importance of consistency. It’s not just about how much you sleep, it’s about when. For diurnal people, that means getting up and going to bed around the same time, even on weekends.
Few studies actually compare long-term health effects among people who work some nights to people who work only nights, but the same principle of consistency should apply. If you can manage to get your body into a 24-hour cycle, that’s beneficial, even if it doesn’t correspond perfectly with that of the sun. The idea has to do with chronobiology: Our circadian-phase shifts have evolved to be dependent on light. Cells in the retina send information about light through the hypothalamus. Gene-transcription feedback loops regulate the pineal gland, which secretes the hormone melatonin.
According to the International Agency for Research on Cancer, the additional risk of cancers in shift workers “may be explained by the disruption of the circadian system that is caused by exposure to light at night. This can alter sleep-activity patterns, suppress melatonin production, and disregulate genes involved in tumor development.” But if you get into a consistent groove of night shifts, you should be able to manipulate light with blackout curtains and lamps.
Some employers think they’re doing people a favor by saying you only have to work one week of nights every month. That’s how we did it in the hospital. But maybe it would’ve been better to work three straight months every year. If I were in Officer Nic’s position, purely from a health perspective, I’d choose consistent night shifts.
The downside to that is, of course, that people also have families and lives, and social isolation is this whole other serious health risk factor. So I can’t choose for you. I’ve worked nights in the hospital and known the isolation that comes with it. There’s a sense of being an actual ghost. You get invitations to social things and initially think, yeah I’ll be there. But then you realize you’ll be asleep. If you start to sacrifice sleep to keep a social life up, you can end up equally miserable.
The actual best solution is to make a gradual transition between day shifts and nights shifts—like if you could start and finish ten minutes earlier every day. That would just be a nightmare for scheduling. And it’s a reminder that most people who have to work frequent night shifts aren’t in a position to be making demands like that. Night-shift jobs and their associated health risks tend to fall to people of lower socioeconomic status, so the risks of shift work tend to go ignored.
In most other areas, if you know that a job is going to involve exposure to a carcinogen, employers are required to minimize that exposure or compensate people according to risk. In the U.S, the Fair Labor Standards Act doesn’t require extra pay for night work. Maybe it should.