Working a night shift never harmed me. Zzzzzz. Photo: Shutterstock

Thursday 13th August 2015

Hard day's night

The surprising dangers of working night shifts

Do people have night shifts where you work, or are they about to? Perhaps you work at London Underground and are already banging your head against the wall about night shifts?

For your viewing pleasure, we’re putting together the biggest issues that night shifts present in one convenient place.

Working on the other side of the clock brings with it a number of challenges: for example, the risk of ghost attack goes up 80%, and you have to turn the backlight up on screens.

But really, working at night poses a number of problems and obstacles that you should be aware of. Human beings were never made for the darkness. The nightlight industry alone is testament to that fact.

If you want to make it at night, you either have giant eyes (lemurs), don’t need eyes (moles), or lots of eyes (the things in our nightmares). Sadly, humans have a paltry pair of pretty average eyes, along with only some tiny tufts of fur to keep warm. Useless.

Unfortunately for us then, some jobs just have to happen at night, whether that be swinging a truncheon in your Amazon prime warehouse, strolling the aisles of your 4am Hong Kong – Heathrow flight, or responding to a medical or criminal emergency.

1) Sleep Pattern Disruption and Fatigue

The obvious candidate. Night shifts, especially when inconsistent, are practically purpose-made to mess with your sleep pattern. Breaking your circadian rhythm, or biological clock, results in you feeling tired and lethargic.

Productivity drops through the floor and decision making gets markedly worse. Accidents in the workplace skyrocket at night because people are working under that “just woke up” fog for hours on end. At worst, it may be like a never-ending feeling of jet lag.

“The basic take-home is that fatigue decreases safety,” says Bryan Vila, PhD, a sleep expert and criminal justice researcher at Washington State University, “Learning healthy sleeping practices is just as important as occupational training,” he believes.

Chances are, even if you try to sleep during the day, you’ll be getting less sleep than you need. Perpetual mild sleep deprivation can really do a number on your health in too many areas to count. Worst of all, your chances of being healthy, wealthy and wise drop dramatically. And then those smug grandmas will have been right all along.

2) Breast Cancer Risk

Probably coming as a surprise to almost everyone, it seems like night shift working brings with it a statistically significant increase in the risk of all cancers, and especially breast cancer. It seems this comes about due to the body failing to produce melatonin, AKA the sleepy time hormone.

Melatonin is produced naturally as darkness falls, meaning that we get sleepy at night time. Light, natural or artificial, inhibits our production of melatonin. It’s why staring at screens at night makes it more difficult to sleep. It protects DNA and can help prevent cancer from developing.

Night shifts can mean you never produce enough melatonin, which increases your risk of cancer. In 2007, the International Agency for Research on Cancer concluded that shift work is “probably carcinogenic to humans,” and the World Health Organization deemed shift work a probable carcinogen.

3) Obesity and Health Issues

Links between a number of health issues and night shift working have been drawn and cannot be explained away by socioeconomic reasons. Heart health, diabetes, digestive issues, and obesity are all strongly linked to night shift work.

Another couple of Bounty bars won’t hurt. Photo: Salim Fadhley, Flickr

Karen Baxter, who advises the NHS on night shift working, suggests that in the short-term night shift working may only cause fatigue, heartburn and indigestion, but “in the longer-term people may develop [more serious] gastrointestinal or cardiovascular problems.”

Some of this may be lack of sleep, and the knock on effect this can have. But night shift workers find it much harder than average to exercise (and not just because you might find your gym closed at 3am during lunch hours), and have a tendency to have worse eating habits — mostly involving junk food.

While Pret may be closed, your friend the vending machine never sleeps. Or judges when you buy five snickers for dinner. Less exercise, poor diet, and lack of sleep come together to form a slew of health problems if not managed correctly.

4) Stress and Mental Illness

The fun doesn’t stop at heart attacks and diabetes either, because night shift working won’t just make you fat, it can also make you sad. Or mad. Possibly both.

This one really depends on the type of night shift work. Perhaps reading Tolstoy in your guard booth for eight hours doesn’t stress you out at all, and your commute is a breeze because there’s no road rage.

However for many, it can be a solitary existence with little scope for interacting with others, which may be worse for the extroverts out there. The incidence of self-reported depression among night shift workers is higher than the average worker.

Professor Jun Li of the University of Michigan, who conducted a study on those with clinical depression noted that very often sufferers “…seem to have the sleep cycle both shifted and disrupted.”

5) Social Deprivation

So you might be a little lonely during your shifts, but the damage may also follow night shift workers home. Different sleeping patterns can destroy family life — parents hardly able to spend time with their kids or partners not even sharing a bed.

It’s no wonder night shift workers have an exceptionally high rate of divorce. It can also be hard for some to maintain their social lives with friends as differing work schedules make meeting up difficult.

The Unite union highlights some of the potential problems: “Disrupted family and social life, for example isolation from friends, family, social events and celebrations of birthdays and anniversaries, sports matches, etc.”

Not too many people successfully transition after work drinks into before work brunches.

6) Brain Ageing and DNA Damage

One study by the University of Swansea and the University of Toulouse showed that irregular shift working for a prolonged period causes the brain to age by an average of 6.5 years, leading to worse memory and speed of processing than those who had never worked irregular shifts.

It took five years for workers to recover and return to their nominal brain age after stopping their shift work.

Recent research by the University of Surrey also suggests that the functioning of rhythmic DNA is disrupted by night shift work. One of the report’s authors, Professor Dirk van-Dijk described it thus: “It’s chrono-chaos. It’s like living in a house. There’s a clock in every room in the house and in all of those rooms those clocks are now disrupted, which of course leads to chaos in the household.“

A coherent analogy, sort of.

Some genes express themselves in time with your circadian rhythm — in the same way that some plants open in daylight and close at night. They do not passively react to the light, but open in accordance with their gene controlled clock.

This is fancy science talk to say you’ll feel like shit if you keep breaking your circadian rhythm, because your biology isn’t as flexible as a shift pattern.

Next week, we’ll shine a light into the darkness and reveal some of the best ways to combat these issues. Until then, sleep tight.

About the author

Jerome Langford

Jerome is a graduate in Philosophy from St Andrews, who alternately spends time writing about HR and staring wistfully out of windows, thinking about life’s bigger questions: Why are we here? How much lunch is too much lunch? What do you mean exactly by ‘final warning’?