Working the night shift can have its perks: often higher pay, reverse commutes and bosses asleep in bed.

Now the bad - and there is a lot, according to growing number of studies: a higher risk of disease and greater vulnerability to sleep disturbances and absenteeism.

Last year, a report commissioned by the World Health Organization found that shift work was a possible carcinogen.

As a night owl myself, I'm thinking, "This is not good."

But it makes sense. All of our bodies have a 24-hour sleep-wake cycle, known as the circadian rhythm, that regulates things like our temperature and how our organs function. Night shifts, jet lag and staying up all night for, say, a Law & Order marathon, disrupts our biological clocks.

Besides that, our bodies do a lot of things at night like make melatonin, a hormone with antioxidant properties. But melatonin needs to be produced in the dark, which presents a problem for people who work through the night, and don't make up the sleep during the day.

There are ways to minimize the negative impact of shift work. Research in this month's American Journal of Preventive Medicine recommends that workers avoid being on the night shift all the time. A better situation would have the worker on nights for several days before rotating to afternoons.

On a "lighter" note, here's the Commodores singing about the night shift I think, metaphorically - but still, what a tune.