We’ve all felt tired after a long day’s work. But for some, their work schedule could be doing real damage. A new study from Occupational and Environmental Medicine has found that shift work strains your brain to the point that it can age several years prematurely. After studying 3,000 people living in France, researchers found that those whose work hours consisted of rotating shifts performed worse in memory exercises and tests of cognitive speed than those who worked nine to five. In fact, those who had done rotating shift work for a decade were found to have an amount of cognitive decline similar to that caused by more than six years of natural aging. Interestingly, those who quit shift work were able to regain their cognitive abilities after five years. Scientists can’t say that there is any particular factor that causes cognitive decline after working irregular hours, but there are a number of things we do know about the problems that can be caused by working irregular hours. 1. The body likes to stick to its circadian rhythm. The body works on a natural clock, so there’s a built-in time when your brain wants to go to sleep at night and wake up in the morning. Research has shown that disobeying your body’s natural circadian rhythm can contribute to things like inflammatory diseases, and working at night with the help of artificial light could even be related to a higher incidence of breast cancer. 2. Sleepless nights will come back to bite you. Researchers have long known that a loss of sleep is bad for your health, but more recently they’ve found that losing those much-needed hours of slumber can lead to impaired memory and even brain deterioration. So work hours that don't let you get your full eight hours could be doing damage. 3. Healthy eating is harder in the middle of the night. It’s not just your sleep schedule that gets confused when you’re working strange shifts; your eating schedule is thrown out of whack too. Meal schedules and appetites change, coffee consumption ramps up, and healthy food choices become limited. Whereas dinner options are numerous at 6 p.m., few healthy restaurants are open for dinner after the midnight shift. And workers who might usually grab food from the grocery store might be restricted to eating from vending machines or convenience stores in the middle of the night. 4. Your body needs some sunlight. Any job that keeps you indoors, away from sunlight, during the day or forces you to sleep during the day and be out at night could lead to a deficiency in vitamin D—a nutrient that’s been linked to everything from bone building to immunity. Those who rarely see sunlight should likely consider taking a supplement. There are some problems you can’ avoid with shift work, but knowing the dangers can help you protect your health. (Photography: Thinkstock)