Research suggests that in general, the more we work, the worse our bodies fare. But how far does that wisdom go? Consider this a guide to help you answer the question: Is work bad for your health?



Are longer hours bad for you?

Perhaps not directly. But they do lead to activities that carry greater health risks.

In 2010, Americans each worked on average a total of 1,778 hours. That's not nearly as bad as South Korea (2,193 hours), but the United States still spends more time at work than many of its fellow developed nations, including Japan, Canada, Spain and the United Kingdom. What happens to your body when you spend more time at the office?

While there's scant credible research to suggest a longer workweek is harmful in itself, scientists have found a link between increased working hours and unhealthy behavior. In particular, working longer can lead to greater rates of cigarette use, less exercise and fewer check-ups, researchers at the University of Illinois discovered in 2010. The inverse also holds true: working fewer hours is linked to healthier behavior. When France cut the legal cap on weekly working hours from 39 to 35 in 1998, workers were 4.3 percent less likely to smoke cigarettes. They were also less likely to abuse alcohol. And for every hour cut from the workweek, the study's participants were 2.2 percent more likely to engage in exercise.

Even if the causal relationship between long workweeks and poor health isn't directly clear, what is clear is that the more time you spend at work, the less you have to take care of yourself. And that's just common sense.



What about working odd hours?

Undoubtedly bad for you. The question is, why?

Some 15 million Americans work evening or overnight shifts, according to the Bureau of Labor Statistics. These night-owls are all at greater risk for Type 2 diabetes, cancer and heart disease, among other afflictions. What do these individuals have in common? Could it be that night workers are universally unhealthy to begin with? Or that healthcare for night workers is somehow different than for their daytime colleagues?

Actually, the link between poor health and hard work is unambiguous here. There is a connection, and it has to do with our natural sleep cycles. Scientists at Harvard Medical School tested this theory in 2009 when they deliberately interfered with their test subjects' circadian rhythms. After being woken progressively later and later in the day for eight days in a row, the subjects' blood samples showed a remarkable decline in leptin, one of the body's hormones responsible for controlling appetite. Stress-related hormones like cortisol rose dramatically, and so too did subjects' blood pressure. Indicators for diabetes, such as blood glucose and insulin, were also at dangerous levels.

Throw it all together, and what you have is a potent cocktail of abnormalities primed for combustion.