7 Healthcast: Graveyard shift could be health hazard

A new study from Brigham and Women's Hospital discusses the danger of working the late shift.

There's new evidence that working the graveyard shift can actually make you sick.

Just when most Americans are getting their normal sleep, 21 million others like Nurse Paula Asci are working nights.

"I average maybe about four hours a day and even on my nights off I average maybe three or four hours sleep. I'm always tired,” said Asci.

Asci works at Brigham and Women's Hospital in Boston where new research provides further evidence of how harmful shift work can be.

Scientists put 21 healthy volunteers in the sleep lab for three weeks. By changing lights irregularly and taking away clocks and other clues about time, they altered the subjects’ normal body clocks.

Within just a few days -- when the volunteers ate -- their bodies responded differently to the food, with dangerous effects.

"Glucose levels went much higher and stayed that way for several hours, This was because of decreased insulin released from the pancreas. Together these reflect an increased risk of diabetes," said Dr. Orfeu Buxton.

Several studies have shown that shift workers are at higher risk for Type 2 diabetes, heart disease and other problems. But this study is one of the first to show exactly how the body is harmed.

The diabetes risk was so great that three of the healthy subjects in the study became pre-diabetic during the experiment. Nine days after returning to a regular sleep wake cycle their metabolism became normal again.

The researchers advise that, when possible, shift workers try to eat when their body clocks are not out of whack.

But Paula Asci and her co-workers know how difficult that can be.

"When it's busy so we don't go on regular meal breaks,” said Stephen McGovern.

The shift workers say there is seldom a time when they feel their body clocks are normal because they mostly feel exhausted.

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