BIOLOGY AND SHIFT WORK
research suggests that biological differences may account for why some
people are "morning people" and others are more energetic at
Emmanuel Mignot, MD,PhD, and his colleagues asked 410 adults when they like to sleep and work. They wanted to know what their ideal schedule would be and when they felt most alert. They also drew blood to look at a gene relating to their genetic "clock" regulating circadian rhythms, or daily sleep-wake schedules.
They found a link between two different forms of the gene and whether people were partial to morning or evening activity.
Most people were brightest in the morning but about 25%said they felt most awake during the late afternoon or evening. These people all had the same form of the "clock" gene.
This is a preliminary study but it has potential to explain why some people cannot function well on off shifts and others thrive while working graveyard.
Published Sept 15 1998, Sleep(Vol.21,No.6,p568-576)