Your parents likely repeated this old adage: Early to bed, early to rise, makes a man healthy, wealthy, and wise.

At the very least, going to bed at a reasonable time after dark may be a good thing. And researchers from Australia are pointing out the drawbacks to living life in opposition of our natural circadian rhythms.

The study parsed 13 million hours of data, collected from light sensors worn by nearly 89,000 participants ages 40 to 69 across the United Kingdom. Data was gathered using wrist sensors that measured light patterns, and the National Health Service monitored how many participants died over an eight-year period.

In short? The team found that exposure to bright nights and dark days, such as those experienced by graveyard-shift workers, is linked to a higher risk of premature death.

Specifically, the team found that those who were exposed to high levels of light at night had a 21% to 34% increase in premature mortality, while those exposed to high levels of daylight had a 17% to 34% lower risk of dying during the study period.

Research suggests that little good comes of disrupting circadian rhythms. Light exposure at night disrupts us partly by weakening the signal in our brains that controls our bodies’ circadian rhythms. Animals also die earlier when they face circadian disruption.

Repeated disruption of those natural rhythms can lead to a variety of unpleasant health problems, including diabetes, obesity, cardiovascular disease, and mental health issues. Not to mention crankiness.

But make your load lighter by eating right, exercising and sleeping when it’s dark as often as you can.