Now, researchers say they've learned that for over a long period of time each hour worked increases an individual's chances of developing heart disease, and they have delivered their findings in a study recently published in The Journal of Occupational and Environmental Medicine.
To start, let's note that this is a retrospective study, without controls established in order to screen for unhealthy behaviors, those unrelated to the amount of time spent at work. But the study does provide some insight.
Past studies have observed what seems a pretty obvious cause-and-effect relationship: that someone who simply works longer hours than average is more likely in general to suffer from heart disease. But now researchers have discovered that the link is proportional: the health threat's intensity corresponds to the increased number of hours.
The study began looking at almost 2,000 men and women starting in 1986. Researchers then followed their health and work history for 25 years, through 2011. Over the study’s span, the researchers found that nearly half of those observed had received cardiovascular disease diagnoses.
According to the Centers for Disease Control, nearly 750,000 Americans suffer a heart attack each year. What's more, roughly 610,000 people annually die of heart disease, representing approximately one in four of all U.S. deaths. Such cardiovascular diseases include angina (chest pains caused by lack of oxygen to the heart), coronary heart disease, heart attack, hypertension and stroke.
In those diagnosed with cardiovascular disease, the researchers found that, over a 10-year span, there was a 1 percent added risk for disease for every added hour worked each week. In addition, they found noticeable increases in risk for heart disease after 45-hour work weeks.
As compared to those working 45 hours, researchers found the chances of heart disease increase by:
- 16 percent for those who worked 55 hours/week
- 35 percent for those who worked 60 hours/week
- 52 percent for those who worked 65 hours/week
- 74 percent in those who worked 70 hours/week
- 100 percent (or double the risk) for those who worked 75+ hours/week
While those conducting the study do not advocate that people change their work habits based on this study’s findings, they still believe it poses serious health concerns. University of Texas School of Public Health assistant professor Sadie H. Conway – the study’s lead author – makes this clear:
“I would never tell a person ‘don’t work long hours’ because of this risk," she said, "but it’s something that shouldn’t be ignored from a public health standpoint.”