If a colleague ever asks you to cover the graveyard shift, think twice about doing them the favor.
Scientists have found that a decade of shifts at odd hours ages the brain by six and a half years. This is in addition to some of the well-known physiological effects of disrupting circadian rhythms, which compels the body to be awake during the day and asleep at night, such as heart disease, ulcers, and a much higher chance of developing of breast cancer.
Teams from the University of Toulouse and the University of Swansea studied 3,200 employed and retired workers in France starting in 1996, measuring their memory, speed of thought, and other cognitive functions over a 10-year period. “It was quite a substantial decline in brain function,” Philip Tucker, part of the team in Swansea, told the BBC. Night workers make more mistakes, and “maybe one in 100 makes a mistake with a very large consequence,” Tucker said.
Indeed. It’s no coincidence that the Exxon Valdez oil spill, the Union Carbide chemical leak in Bhopal, and the Chernobyl radioactive disaster all took place during the night shift.
But it isn’t all bad news for night owls; the research found that those who stopped working after-hours shifts eventually regained their normal mental agility—after five years.
That is not a luxury that some can afford—our 24-hour society often requires people to work late, usually the youngest and poorest. Tucker suggests that employers be mindful of the health consequences of shift schedules and conduct regular medical check-ups. For his part, Tucker added that he would never do night shifts “if I could possibly help it.”