A new study published in Current Biology has found that people who have irregular sleep patterns have much greater risk of getting cancer.

These tests showed “unequivocally” that such poor sleep habits result in cancer in mice, and it may raise some important issues doctors may need to raise with their patients about managing work and health, according to a BBC report.

In fact, researchers went as far as to say that women who have a family risk of breast cancer should entirely avoid working shifts, although they did acknowledge that more research may be needed.

And it may have an impact on your waistline too. The study found that animals were 20 percent heavier when they had irregular sleep patterns, even though they consumed teh same amount of food.

Why? Scientists think it may have something to do with disrupting the internal rhythm of the body, which increases the risk of the body getting some sort of disease.

But scientists don’t know a whole lot about this link, because it can be muddled by other factors: for example, someone working a shift may also develop disease for other related reasons, like a lack of vitamin D, low activity levels, or other things.

To come to their conclusions, researchers delayed the body clock of mice by 12 hours every week for a year. Typically, all mice would get tumors at 50 weeks, but those with their sleeping patterns disrupted saw them develop eight weeks earlier.

So what can you do? Unfortunately, it may mean you need another line of work if you work rotational shifts. Other than that, make sure you visit your doctor regularly so he can keep an eye out for any problems.