Body Clocks Sleep and Society
[Music]
[Applause]
most of us
live in the 95 world and we’re expected
to be awake
alert and functioning during that time
which means
sleeping at night and waking up in the
morning
not everyone can do this as a sleep
specialist
i see many people who cannot fall asleep
and wake up
at quote unquote normal hours
at night their minds are busy very
productive
alert creative without coffee
buzzing at the time when everyone else
wants to sleep
there are zombies in the morning so they
naturally feel sleepy at 1
2 or 3 a.m and when they sleep they
sleep well
but they wake up at midday
but since we live in a nine-to-five
world
they have to get up in the morning for
work or school they only get four or
five hours of sleep
and are struggling the rest of the day
mornings are particularly tough some use
several alarms they program their phones
to ring every three minutes they have
this love affair
with the snooze button they ask family
members and flatmates
to physically get them out of bed
daily battle which includes water
pistols wet
face cloths and literally dragging
bodies
into the shower and some even
fall asleep in the shower
but because of their fatigue and poor
functioning
they have been labeled as lazy
unmotivated and even depressed
we call them night owls in sleep
medicine
we call them delayed sleep face wake
disorder so let’s just call them owls
easier humans
have a range of body clocks we have owls
we have rare early birds and most of you
most of us here are boring in the middle
we call the in-betweeners
even among owls you have the hard-core
genuine owls
and the mild owls very rare are the
genuine larks they’re very rare
who sleep at seven pm and wake up at two
in the morning
about 0.025 percent
of the population another rare body
clock are what we call
free runners so their body clocks
get later and later one hour every day
so let’s go back to night owls night
owls through no fault of their own
are naturally wired to feel sleepy after
midnight and wake up close to midday
statistics show about one to two percent
of the population
have this condition interestingly from
the age of 13
teenagers also become temporary owls
so a study we did in australia of about
a thousand kids
high school kids showed that close to 50
percent of them
are actually owls so when are
when your teenager is sleeping and
waking up waking up late
they’re not deliberately doing it to
annoy you
so let’s talk about body clocks for a
moment
all organisms plants humans
animals sorry insects birds mammals
worms cats dogs they all have body
clocks
you know that at 607 in the morning your
cat will try to wake you up for a fee
it runs on time unless we shift to
daylight savings
in humans we have a master clock deep
inside the hypothalamus of the brain
it’s called
the suprachiasmatic nucleus or the scn
it’s the size of a pinhead 20 000
neurons
and it controls the timing of our sleep
our waking up
our alertness our drowsiness when
hormones are secreted
moods peak physical performance and when
you do
your number ones and twos
our master clocks timing is strongly
influenced
by the sun early morning sun
sets the time for organisms and in the
evening in the
absence of bright light melatonin also
known as the dark hormone is released
melatonin tells the body to prepare for
sleep in an
hour or two so for many of us melatonin
is released around 9 pm
which makes us feel a little sleepy
around 10 or 11 pm
for teenagers on other species
melatonin is released naturally delayed
at least by two hours so which makes
them sleepy around 11 pm or later
which then delays their waking up time
and in the past 200 years
with light bulbs artificial light
powerful led and halogen lamps
and more recently with bright
smartphones and devices
our brains and sleep patterns are now
confused
so blue light is worse for teenagers who
are constantly on their screens before
they sleep
let’s go back to night owls
why are there clocks set later than most
of us
number one we know that in chronobiology
which is
the field of science of biological
clocks
that there are genes that code for the
timing
of our body clocks so now genes are now
being identified
that’s responsible for delayed sleep
phase or owls or for your clocks or for
everyone’s clocks
so their clocks are slightly different
from most of us
and i can see owls running families so
if i have a patient who is an
owl most of the time there will be
family members
clustered as owls and
owls actually may be more sensitive to
bright light
more sensitive than us so bright light
in the evening
wakes them awake it wakes them up
stimulates them and alerts them
so because because owls appear to be
more sensitive to the effects of bright
light at night
blasting their eyes also again with
gadgets and devices
further delayed their sleep
so what are the consequences of also we
laugh about owls we laugh about larks
but there are huge consequences
there’s health consequences many of them
are chronically fatigued
they have metabolic issues weight gain
issues diabetes
and a host of other physical problems
because they’re constantly sleep
deprived
we’re not even talking about
psychological consequences owls tend to
have higher rates
of depression low self-confidence when
it comes to work
many of them poor work their work
performance is poor
particularly in the morning kids are
falling asleep the first two three hours
of school i’m not even talking about
relationship dramas especially if an owl
marries a lark
it’s actually can can make the
relationship stronger because they don’t
see each other
so why don’t we just tell owls to go to
bed
10 pm force themselves to get up at six
in the morning
just muscle it through it’s like telling
all of you who have an average clock
to go to bed at 6 00 pm sleep and wake
up
at 2 to work
are there options for night owls
fortunately there are
so for teenagers there’s there are a few
schools now in australia in the us and
in the uk
that have later school start times
and they’ve shown huge benefits for
teenagers when it comes to their school
performance
truancy and even their moods
we also can trick the brain
trick the brain of owls temporarily to
make them sleep earlier
so one technique is to avoid bright
light after sunset
you dim the lights you use blue light
blockers you use
night modes in your gadgets for some of
my patients my prescription is
no devices by 6 pm
which is hard and then another way to
trick the brain
to make them sleepy is melatonin
strategically timed so we calculate the
time they have to take melatonin to help
them go to sleep
we can also trick the brain for them to
wake up earlier
so this is using bright light in the
morning
usually the sun is the best source a
hundred thousand lux that’s really
powerful but new zealand is not
consistent with the sun
so we use light boxes we have gadgets
boxes of light with leds
and even light visors but they have to
use it again at a particular time we
calculate it
and for 30 minutes they have to be using
this bright light
and that can wake them up
so when these tricks work night owls can
sleep before midnight and wake up at
seven in the morning
and for them this is miraculous
however these tricks don’t work all the
time
they work only about 60 70 percent of
the time
and they’re temporary if they stop
melatonin if they stop bright light
treatment
they revert back to owls so the ideal
option
if you ask me is to allow owls
to follow their own body clock i have
patients who are
lucky enough who are able to reconfigure
their work
and study time to confirm to conform to
their biological rhythm
but not a lot of people can do that
they get up at midday work in the
afternoon and evening and sleep
after midnight and they feel great but
again
it’s not possible for everyone so the
bottom
line is we all have different body
clocks
but the majority has dictated to
everyone what time we should work and go
to school
our society unwittingly discriminates
against night owls so for the night i’ll
sat there
don’t listen to people when they call
you lazy
listen to your body clock instead thank
you
you