| Sleep tight with melatonin
|
2000-09-16
Andy Coghlan - New Scientist
PEOPLE
who are totally blind don't sleep too well at night. Their body
clocks go awry because they can't sense any light, so they can't tell
night from day. Now researchers have found a treatment: the
anti-jet-lag hormone, melatonin.
"Light
is the major time cue in humans," says Debra Skene of the
University of Surrey in Guildford. In sighted people with normal body
clocks, levels of melatonin in the blood peak at around 4 am. In
totally blind people, melatonin peaks at a different time each day.
Their sleep suffers, so they often nap during the day to compensate
for their disturbed nights.
Skene
wondered if the body clock of completely blind people could be reset
with daily doses of melatonin. In an experiment on seven totally
blind volunteers with severe sleep disruption, she found that the
melatonin treatment gave most a better night's sleep, with fewer
daytime naps.
Later
she found that the treatment only reset the clock if it was timed
correctly in relation to the subject's own melatonin peak. "Melatonin
can work, but we need to know the status of the clock before we begin
treatment," she says.
From issue 2256 of New Scientist
magazine, 16 September 2000, page 21
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