|
|
You and your child - Sleep
Sleeping
Patterns Are Governed by Light
Your biological clock is not the only thing
that reminds one to shut eye every 24 hours;
a new study has found that it's actually
light that governs your sleeping patterns.
Your eyes use light to reset your biological
clock through a mechanism that is separate
from your ability to see, researchers at
Johns Hopkins University found.
Researchers genetically modified laboratory
mice so that a particular set of retinal
ganglion cells -- the ones that receive
input from the rods and cones of the eyes
and send information to your brain -- no
longer functioned. The mice were still able
to use light to see normally, but had great
difficulty synchronizing their circadian
rhythms to light or dark cycles.
 The
findings suggest that people who have
trouble sleeping or seasonal depression may
be having a malfunction that is contributing
to their inability to detect light, which in
turn may adversely affect their biological
clocks.
Sources:
The Time of India April 29, 2008
Nature April 23, 2008
"This is a
CRUCIAL part of health maintenance that many
overlook. They are insensitive to the fact
that electrical lighting is a relatively
recent innovation and less than a century
ago this simply was not available. This
modern convenience has sabotaged the health
of a large percentage of the population for
not paying close attention to how to make
adjustments for this modern-day convenience.
Organisms evolved to adjust themselves to
predictable patterns of light and darkness,
in a physiological cycle known as the
circadian rhythm. Once artificial light
effectively varied the length of a day, the
average night's sleep decreased from around
nine consistent hours to roughly seven,
varying from one night to the next.
 The
irregularity prevents circadian rhythms from
adjusting to a pattern, and creates a state
of permanent "jet lag."
So while electricity and efficient lighting
have clearly provided major benefits to
society, these benefits come with a price --
the betrayal of your inner clock.
Get the
Light Out of Your Bedroom
It would serve you well to do a thorough
“light check” of your bedroom, as any source
of light -- even one as tiny as the green
glow from your clock radio -- could be
interfering with your ability to sleep, and
more importantly, your long term health and
risk of developing cancer.
While it’s typically thought that your
biological clock is what tells you when it’s
time to wake up or go to sleep, light and
dark signals actually control your
biological clock. To get more specific, a
part of your brain called the
Suprachiasmatic Nucleus (SCN) -- a group of
cells in your hypothalamus -- controls your
biological clock. And the cells that make up
your SCN respond to light and dark signals.
Light actually travels through your eye’s
optic nerve to your SCN, where it signals
your body’s clock that it’s time to wake up.
Light also signals your SCN to initiate
other processes associated with being awake,
such as raising your body temperature and
producing hormones like cortisol.
Meanwhile, when your eyes signal to your SCN
that it’s dark outside, your body will begin
to produce melatonin, a hormone that helps
you sleep and radically decreases your risk
of cancer. There are many studies on this
powerful association. The more your sleep is
disrupted by light pollution, the lower your
melatonin levels and the greater your risk
of developing cancer becomes.
Melatonin is secreted primarily in your
brain and at night it triggers a host of
biochemical activities, including a
nocturnal reduction in your body's estrogen
levels. It’s thought that chronically
decreasing your melatonin production at
night -- as occurs when you’re exposed to
nighttime light -- increases your risk of
developing cancer.
In fact, one of the first studies linking
cancer to light showed that blind women have
a 36 percent lower risk of breast cancer
compared to sighted women. Why? Because they
are unreceptive to light. This means that
their bodies maintain high melatonin levels
at night regardless of how much light is in
the room.
It really is a fascinating system.
What
Happens When Your Biological Clock is
Disrupted?
Your body depends on your biological
clock to steadily regulate your sleep/wake
cycle, but when this process gets thrown off
balance, it can wreak havoc on your health.
And it is actually quite easy to disrupt
your body clock. For instance, all of the
following can confuse your body and make it
think you should be awake when you should be
sleeping, or vice versa:
-
Staying up
late
-
Working
the night shift
-
Turning on
a light in the middle of the night
-
Using a
night light
-
Switching
time zones (jet lag)
-
Eating in
the middle of the night or too close to
bedtime
Your body’s
internal clocks (you actually have many, in
your brain, lungs, liver, heart and even
your skeletal muscles) influence so many
things -- from your heart rate to body
temperature and hormone production -- that
when they’re thrown out of whack all kinds
of things can happen. For instance, a
disrupted body clock may cause you to you
gain weight or increase your risk of cancer.
Using Darkness to Help You Sleep
Making simple changes in your bedroom to
keep the light out during the night can have
a major impact on your sleep quality. Even
the chiropractor at my office, Dr. Lloyd
Fielder, was surprised at the benefit when
he installed blackout drapes in his bedroom.
He was shocked at how much better he felt --
it radically improved the quality of his
sleep. Personally, I sleep in a room that is
so dark, it’s even pitch black at noon. You
can achieve this in your own bedroom by:
-
Installing
blackout drapes
-
Closing
your bedroom door if light comes through
it, and even putting a towel along the
base to prevent light from seeping in
-
Getting
rid of your electric clock radio (or at
least covering it up at night)
-
Avoiding
night lights of any kind
-
Keeping
all light off at night (even if you get
up to go to the bathroom) -- this
includes the TV!"
http://articles.mercola.com/sites/articles/archive/2008/05/20/sleeping-patterns-are-governed-by-light.aspx?source=nl
|
 |
