WEDNESDAY, Aug. 19, 2015 (HealthDay News) -- Millions of workers who put in lots of overtime may be upping their odds for a stroke, a new study contends.
"Working long hours is associated with a significantly increased risk of stroke, and perhaps also coronary heart disease," study author Mika Kivimaki, a professor of epidemiology at University College London, said in a news release from The Lancet. The journal published the findings Aug. 19.
The study couldn't prove cause and effect, but one expert said today's harried workers should seek ways to curb the risk.
"The take-home message for all the workers burning the midnight oil: Make time for physical activity, ensure a proper diet, watch your alcohol consumption and ensure good sleeping habits," said Dr. Paul Wright, chair of neurology at North Shore University Hospital in Manhasset, N.Y.
"If you are not feeling well or if something does not feel right, see your physician," he added.
In the study, Kivimaki's team looked at data from 25 studies that included more than 600,000 men and women in the United States, Europe and Australia. Participants' health outcomes were followed for an average of 8.5 years.
In that study, people who worked 55 hours or more per week were 13 percent more likely to develop heart disease than those who worked the standard 35 to 40 hours a week.
A second analysis of data from 17 studies included nearly 529,000 men and women who were followed for an average of more than seven years. It found that those who worked 55 hours or more a week were one-third more likely to suffer a stroke than those who worked the standard number of hours.
And the longer hours people worked, the higher their stroke risk, the study found. Compared to those who worked a standard number of hours per week, the risk of stroke was 10 percent higher among those who worked 41 to 48 hours and 27 percent higher among those who worked 49 to 54 hours.
Why could long hours at the factory, shop or office be tough on your health? The study authors said a number of factors -- physical inactivity, higher drinking rates and higher stress levels -- may be to blame.
Wright acknowledged that one solution -- simply working less -- is not always in the employee's power.
"Many individuals may not be able to decrease their work hours," he said, so "we need to start to change society's mindset and educate the public that physical activity must be a part of the equation for successful aging and disease prevention."
Also, the study found that "people with long work hours tended not to go to the doctor for evaluations," Wright noted. "With [some] companies now promoting wellness programs, this will hopefully change."
Dr. Stephan Mayer directs neurocritical care at Mount Sinai Health System in New York City. He said that he was "surprised" by the magnitude of the effect seen in the study.
"The risk is almost as bad as smoking, which increases the risk of stroke by about 50 percent," he said. "Although we don't know for sure, to my mind the most plausible explanation is chronic triggering of the stress response that comes with working long hours, pressure to perform, and not enough time for family, loved ones and peaceful rest. "
Mayer believes the findings are "further evidence that we as individuals need to be mindful of and take responsibility for work-life balance."
The U.S. National Institute of Neurological Disorders and Stroke outlines how to prevent stroke.