Let your boss know: A new study shows that middle-aged people who labor for very long hours have lower score on mental function tests. The study, published in the American Journal of Epidemiology, analyzed the performance of 2,214 middle-aged British civil servants on a battery of thinking tests given over two time-periods from 1997 to 2004.The researchers reported that when the subjects were given cognitive tests, those who worked more than 55 hours per week scored lower on vocabulary and reasoning exams than people whose work weeks lasted 40 hours at most. Long working hours were also predictive of lower reasoning and lower vocabulary scores on follow-up tests at the end of the study period. These results held true regardless of age, sex, marital status, education, occupation, income, physical diseases, psychosocial factors, sleep disturbances, and health risk behaviors.
“Decline in cognitive function has already been shown to be present among the middle-aged," the researchers wrote. "As mild cognitive impairment predicts dementia and mortality, the identification of risk factors for mild cognitive impairment in middle age is important."
The study's findings are significant, researchers say, because the cognitive impairment experienced by middle-aged people who work long hours may be similar in magnitude to those caused by smoking, which is a known risk factor for dementia.
