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