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Does shift work hurt your brain? Memory, processing affected: study

People who live in a big city might find that they wake up feeling tired. And that might be because the streetlights are making it more difficult for you to sleep. Rex Features/The Canadian Press

TORONTO – Your alarm clock goes off as your family is eating dinner. When it’s bedtime, you’re off to work.

A new study suggests that shift work is akin to chronic jet lag. Research has already suggested it disrupts the body’s circadian rhythm, but now European scientists say it’s also toying with brain function from memory to processing speed.

It’s especially emphasized in people who rotate around morning, evening and overnight shifts.

“The cognitive impairment observed in the present study may have important safety consequences not only for the individuals concerned, but also for society as a whole, given the increasing number of jobs in high hazard situations that are performed at night,” the researchers warned in a statement.

“It may also affect shift workers’ quality of life, with respect to daily life activities that are highly dependent on the availability of cognitive resources.”

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READ MORE: Is chronic fatigue real? New research says it’s tied to brain anomalies

Shift work has been linked to heart disease, cancer and mental health issues but it’s unclear how it affects the brain.

That’s why French and Welsh researchers studied more than 3,000 people who were working in a wide range of sectors during three different times: 1996, 2001 and 2006.

Half of the sample – taken from patient lists of three occupational health doctors in three different parts of Southern France – worked shifts for at least 50 days of the year.

The study participants were exactly 32, 42, 52 and 62 years old during the first set of testing – the researchers assessed short and long-term memory, processing speed and overall cognitive abilities.

READ MORE: Interrupted sleep just as bad for you as no sleep at all, study suggests

Turns out, those who worked shifts scored lower on memory, processing speed and overall brain power, the study suggests. Their scores were lower than those who worked normal office hours.

In the second set of tests, results found that people who did shift work for a decade or more had scores on par with people who had 6.5 years of age-related cognitive decline.

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But the researchers also asked if stopping shift work could reverse the damage. It’s possible, they say. The effects wear off after about five years.

The researchers can’t say why these patterns occurred in shift workers but they suggest a “disruption” to the body clock could lead to physiological stress, which in turn affects the brain.

Other studies blame a vitamin D deficiency caused by lack of exposure to sunlight.

The researchers’ full findings were published Monday night in the British Medical Journal.

READ MORE: Self control is within our reach, even when we’re tired, scientists say

“The current findings highlight the importance of maintaining a medical surveillance of shift workers, especially of those who have remained in shift work for 10 years or more,” the researchers concluded.

They say another decade-long study of shift workers could be worthwhile.

The conventional 35 to 40-hour work week is facing criticism as some workplaces give it a modern day makeover.

READ MORE: What do you think of Richard Branson’s ‘unlimited holiday’ policy?

One Mexican billionaire proposed to his employees a work week that’s only three days long, but with 12 hour shifts.

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In another scenario, British billionaire Richard Branson ushered in “unlimited holiday” to his employees. They can request as much time off as they’d like as long as they stayed on top of their priorities in the office.

carmen.chai@globalnews.ca

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