Late nights 'sap children's brain power'

Late nights and lax bedtime routines
can blunt young children's minds,
research suggests.
The findings on sleep patterns and brain
power come from a UK study of more
than 11,000 seven-year-olds.
Youngsters who had no regular bedtime
or who went to bed later than 21:00 had
lower scores for reading and maths.
Lack of sleep may disrupt natural body
rhythms and impair how well the brain
learns new information say the study
authors.
They gathered data on the children at
the ages of three, five and then seven to
find out how well they were doing with
their learning and whether this might be
related to their sleeping habits.
Erratic bedtimes were most common at
the age of three, when around one in
five of the children went to bed at
varying times.
By the age of seven, more than half the
children had a regular bedtime of
between 19:30 and 20:30.
Overall, children who had never had
regular bedtimes tended to fare worse
than their peers in terms of test scores
for reading, maths and spatial awareness.
The impact was more obvious
throughout early childhood in girls than
in boys and appeared to be cumulative.
The researchers, led by Prof Amanda
Sacker from University College London,
said it was possible that inconsistent
bedtimes were a reflection of chaotic
family settings and it was this, rather
than disrupted sleep, that had an impact
on cognitive performance in children.
"We tried to take these things into
account," said Prof Sacker.
The children with late and erratic
bedtimes came from more socially
disadvantaged backgrounds and were
less likely to be read to each night and,
generally, watched more TV - often on a
set in their own bedroom.
After controlling for such factors, the link
between poorer mental performance and
lax bedtimes remained.
The findings are published in the Journal
of Epidemiology and Community
Health .
Prof Sacker said: "The take-home
message is really that routines really do
seem to be important for children.
"Establishing a good bedtime routine
early in childhood is probably best, but
it's never too late."
She said there was no evidence that
putting children to bed much earlier than
19:30 added anything in terms of brain
power.
Dr Robert Scott-Jupp of the Royal College
of Paediatrics and Child Health said: "At
first glance, this research might seem to
suggest that less sleep makes children
less intelligent, however, it is clearly
more complicated than that.
"While it's likely that social and biological
brain development factors are inter-
related in a complex way, in my opinion,
for schoolchildren to perform their best,
they should all, whatever their
background, get a good night's sleep."