Research/studies Shift work

Shift workers should skip high-iron foods at night, researchers say


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Salt Lake City – Shift workers who eat high-iron foods at night may disrupt their liver’s circadian clock and experience abnormal blood glucose levels, indicates a new study from the University of Utah.

Disrupted circadian clocks, some experts believe, are the reason that shift workers experience higher incidences of type 2 diabetes, obesity and cancer.

As part of the study, the researchers fed iron to mice and found that it increased the cellular concentration of heme, an iron compound in hemoglobin. A circadian protein’s activity increases when heme binds to it.

Increased activity of the protein when the circadian clock is out of synch, such as during a graveyard shift, could lead to abnormal blood glucose levels, the study states.

“When you add iron, it’s resetting those proteins and how they’re functioning and their timing. It’s not an idea of iron is bad – it’s when you’re eating iron,” Judith Simcox, the study’s lead author and a University of Utah postdoctoral fellow in biochemistry, told Safety+Health magazine. Simcox suggested avoiding foods such as steak, other red meat and spinach at night.

The study was published online Oct. 14 in Diabetes.