This is the VOA Special English Health Report.
next time you think about going without sleep, consider this: Laboratory
animals that are kept awake for long periods of time ... die.
sleep scientist Ying-Hui Fu at the University of California, San
Francisco, says little is known about the basic need for sleep.
YING-HUI FU: "We do not know why some humans need more
sleep; why some humans need less sleep; why, when we do not sleep, we do not function
well. We just do not know much about sleep at all."
here is something that scientists now know: A team led by Professor Fu has reported
the first genetic link to how much sleep we need.
The team was looking for a natural clock
in the body that controls sleep and wakefulness. What they found was a genetic
abnormality. People who have this mutation need less sleep than others.
But keep in mind that the scientists say
this mutated gene may be rare. The study involved two members of an extended
family. They did fine on just six hours of sleep a day. Studies have shown that
over time, most humans need eight to eight and a half hours of sleep for the
test their theories, the scientists genetically engineered the mutation in
mice. The mice with the mutation needed less sleep than normal mice. They were
also more active even after being kept awake.
study appears in the journal Science. The researchers will continue to study
the mice to test whether the gene is related to other medical conditions. And
they will study whether it is involved in controlling sleep quantity alone, or
also what scientists call the "wakefulness-behavioral drive." This
drive is important for getting food, shelter and mates.
How you sleep can be as important as how
much you sleep -- especially for newborn babies. A new report says images in parenting
and women's magazines may send the wrong message about how to put babies to
The study found that more than one-third
of the pictures in women's magazines showed babies in unsafe sleep positions. They
showed babies sleeping on their sides or stomachs. Also, only a third of the
pictures showed sleep environments considered safe by the American Academy of
academy says babies should sleep on their backs. It says they should be placed on
a separate sleep surface from their parents, without blankets, pillows or other
soft bedding. These guidelines are credited with reducing cases of sudden infant
death syndrome in the United States.
that's the VOA Special English Health Report, written by Caty Weaver with
Jessica Berman. For more health news, go to voaspecialenglish.com. I'm Mario Ritter.