Levels of estrogen and progesterone fluctuate during a
woman’s menstrual cycle and are thought to affect
women’s sleep
Pregnancy brings with it a host of sleep-disrupting
symptoms among women, as does caring for children
Menopause brings its own set of troubles for women’s
sleep, including hot flashes and night sweats
By Dr. Mercola
Both men and women need high-quality sleep to function optimally,
but women are far less likely to achieve this than men.
One poll by the National Sleep Foundation (NSF) revealed that
two-thirds of women experience a sleep problem at least a few nights
each week and up to half said they wake up feeling unrefreshed.1
In a separate NSF poll, women were more likely than men to report
experiencing insomnia at least a few times a week, and the average
woman between the ages of 30 and 60 reported sleeping just six hours
and 41 minutes on weeknights (even though closer to eight hours is
optimal).2
Why Are Sleep Troubles More Common in Women Than Men?
There are quite a few reasons — from biological factors to more
practical matters like child care — why women's sleep may be lower
quality, and more sporadic, than men's.3
Shifts in Hormones
Levels of estrogen and progesterone fluctuate during a
woman's menstrual cycle and are thought to affect women's sleep.
Dianne Augelli, M.D., a sleep expert at the Weill Cornell Center
for Sleep Medicine at New York-Presbyterian, told New York
Magazine:6
"Estrogen works on several different neurotransmitter
pathways that may have an impact on the regulation of sleep,
and progesterone can have a hypnotic property … Fluctuations
in these hormones may have an effect on the circadian
rhythm."
Pregnancy and Children
Pregnancy brings with it a host of sleep-disrupting symptoms,
like physical discomfort, frequent trips to the bathroom, and
heartburn. Conditions such as restless legs syndrome and
sleep apnea may also begin during pregnancy and interfere
with sleep.
After pregnancy, care of the baby, then toddler, further
interferes with quality sleep. Even after children start
sleeping through the night, many women have trouble sleeping as
soundly as they used to.
Menopause
Menopause brings its own set of troubles for women's sleep,
including hot flashes and night sweats. Obstructive sleep apnea
also tends to increase in women during the menopausal and
post-menopausal years, and a key symptom of this may be
insomnia.
Stress, Anxiety and Depression
Women tend to be more vulnerable to feeling sadness and
anxiety than men, according to research, and feel the pressures
of stress more than their male peers, both at work and at home.
Stomach-churning anxiety, for example, is far more common in
women than men, as are feelings of sadness in response to
stress, and not being able to stop thinking about that which
worries them.5
All of this can interfere with a sound night’s sleep.
Circadian Rhythms Change in the Elderly
Elderly people are another population that tends to have
increased trouble sleeping. Health issues, such as frequent
urination or pain, can keep seniors up at night, as can sleep apnea.
Further, as you get older your body's internal clock gradually
adjusts to earlier bedtimes and wakeup times. If you don't listen to
your body and go to bed earlier (instead choosing to stay up late),
sleep deprivation may result.6
Your circadian rhythm (sleep-wake cycle) actually "drives" the
rhythms of biological activity at the cellular level, and
certain genes regulate these daily activity patterns.
Researchers from the University of Pittsburgh School of Medicine
in Pennsylvania recently looked into the rhythm of such gene
activity in the brain and particularly how it changes with age.
By analyzing thousands of genes from brain samples, they found
significant changes in the daily rhythms of older people. As
reported by Medical News Today:7
"They found that younger people had the daily rhythm in
all the classic 'clock' genes. Older people appeared to have
lost rhythm in many of these genes, but they also had a set of
genes that gained rhythmicity.
Senior investigator Colleen McClung, Ph.D., believes this
could explain some of the changes that older people experience
in sleep, cognition and mood.”
The discovery may also help explain some of the molecular changes
that occur in people with depression (which is associated with
disruptions to daily routines). It may also help explain why people
with dementia may become more agitate and confused in the evening (a
phenomenon known as "sundowning.")8
How Changing Your Diet Might Improve Your Sleep
If you're having trouble sleeping, your diet might be the
last factor you'd consider changing in order to help — but it
should be among the first. Excessive daytime sleepiness and poor
sleep quality are common symptoms reported by obese people.
Dietary changes may help to combat this, regardless of body
weight, according to new research. The study involved obese mice
that were fed either a regular or high-fat diet for eight weeks.
Some of the mice were then switched to the alternative diet for
one week, which resulted in weight gain and loss among the high-fat
and regular diet groups, respectively.
At Week 9 of the study, the two diet switch groups had similar
body weight but significant changes to their sleep/wake cycles,
which were thought to be caused by the acute dietary changes.
According to the study, which was published in the journal Sleep:9
" … [A]nimals switched to HFD [high-fat diet] (and thus
gaining weight) had decreased wake time, increased NREM sleep
time, and worsened sleep/wake fragmentation compared to mice
switched to RC [regular chow] (which were in weight loss).
These effects were driven by significant sleep/wake
changes induced by acute dietary manipulations (Week 8 → Week 9)
… Acute dietary manipulations are sufficient to alter sleep and
wakefulness independent of body weight and without effects on
sleep homeostasis."
The implications of this study are that obese people likely don't
need to lose all of their excess weight to begin to experience
improvements in sleep. Changing to a healthier diet that jumpstarts
weight loss may lead to improved sleep even after just a short time.
Certain Foods Are Known to Help Promote (and Disturb) Sleep
Many people grew up drinking a glass of warm milk before bed to
help lull them into sleep, and you may have "graduated" as an adult
to a cup of warm chamomile tea, which is known for its calming
properties. Certain foods, too, are known for their sleep-inducing
effects.
Cherries, for instance, are a natural source of the "sleep
hormone" melatonin, and drinking tart cherry juice has been found to
be beneficial in improving sleep duration and quality.10
Alternatively, almonds and spinach are rich in magnesium, which
is known for promoting sleep and relaxing muscles. In general,
eating a high-protein snack several hours before bed may help you
sleep, as it can provide the L-tryptophan needed for your melatonin
and serotonin production.
Foods and beverages with too much caffeine would certainly be
among them, but so would spicy foods before bedtime, which are
linked with more time spent awake during the night and taking longer
to fall asleep.11
I recommend avoidingbefore-bed snacks and
stopping eating at least three hours before bedtime.
Not only is this important to optimize your mitochondrial
function and prevent cellular damage from occurring, but it will
also lower your blood sugar during sleep and help minimize damage
from too much sugar floating around.
Additionally, it will jumpstart the glycogen depletion process so
you can shift to fat-burning mode. A study published in the
Proceedings of the National Academy of Sciences is a powerful
confirmation of this recommendation, as it found that the mere act
of altering your typical eating habits — such as getting up in the
middle of the night for a snack — causes a certain protein to
desynchronize your internal food clock.12
This can throw you off kilter and set a vicious cycle in motion.
Eating too close to bedtime, or very late at night when you'd
normally be sleeping, may throw off your body's internal clock and
lead to weight gain. Routinely eating at the wrong time may
not only disrupt your biological clock and interfere with your
sleep, but it may also devastate vital body functions and contribute
to disease.
Do You Really Need Eight Hours of Sleep a Night?
It's often said that modern-day humans' sleep suffers from our
24/7 lifestyles. However, UCLA researchers studied pre-industrial,
hunter-gatherer societies in Tanzania, Namibia and Bolivia and found
they do not sleep more than "modern" humans.
Instead, members of these societies sleep about 5.7 to just over
seven hours a night, going to bed several hours after sunset and
often awakening before sunrise.13
This seems to suggest that perhaps modern humans don't need as much
sleep as we've been told.
However, this was addressed in an interview by Chris Kresser with
Dan Pardi, a researcher who works with the Behavioral Sciences
Department at Stanford University and the Departments of Neurology
and Endocrinology at Leiden University in the Netherlands.
According to Pardi, the sleep duration, which is the length of
time the hunter-gatherers actually spent sleeping, was between 5.7
and 7 hours. However, the sleep period, which is the total time
spent in bed, was 7 to 8.5 hours a night. As long as you're
providing your body with adequate time in bed, it's OK if sometimes
you sleep more and sometimes less. Pardi told Chris Kresser:14
"Sometimes you'll sleep more, and sometimes you'll sleep
less, but you want to give your body adequate time for what I
call 'complete sleep,' which is allowing all of the homeostatic,
physiological processes that are taking place during sleep to
not be interrupted by artificial means, like an alarm clock …
Very few people are going to go to bed at 10 and wake up at 6
and actually get 8 hours of sleep in that interval.
So this study … from a practical perspective, it doesn't
change what the recommendations have been and what you've been
saying and I've been telling my audience for some time now [to
get about eight hours of sleep a night].
… If you worry too much about getting 8 hours of sleep,
let's say you're tracking it and you notice you're in bed for 8
but you're getting 6, don't worry. That's not uncommon. A lot of
these findings are not actually inconsistent with sleep findings
from the lab. You'll bring somebody in the lab, they'll be there
for 8 hours, but they'll sleep for 6 hours and 45 minutes."
For more information about the
importance of sleep, you can listen to my 2014 interview with
Dan Pardi, below.
Another important point Pardi mentioned has to do with how
temperature affects your sleep. The UCLA study found that
temperature appears to be a major regulator of human sleep duration
and timing. According to Current Biology:
"The sleep period consistently occurred during the
nighttime period of falling environmental temperature, was not
interrupted by extended periods of waking, and terminated, with
vasoconstriction, near the nadir of daily ambient temperature.
The daily cycle of temperature change, largely eliminated from
modern sleep environments, may be a potent natural regulator of
sleep."
Indeed, thermoregulation — your body's heat distribution system —
is strongly linked to sleep cycles. Even lying down increases
sleepiness by redistributing heat in your body, from the core to the
periphery.
When you sleep, your body's internal temperature actually drops
to its lowest level, generally about four hours after you fall
asleep. Scientists believe a cooler bedroom may therefore be most
conducive to sleep, since it mimics your body's natural temperature
drop.
This is also why taking a warm bath 90 to 120 minutes before
bedtime may also help you sleep; it increases your core body
temperature, and when it abruptly drops when you get out of the
bath, it signals your body that you are ready for sleep. While
there's no set consensus as to what temperature will help you sleep
the best, in most cases any temperature above 75 degrees Fahrenheit
and below 54 degrees will interfere with your sleep.15
Once you're within that range, many factors can influence which
temperature is best for you including, of course, your choice of
pajamas and bedding. Many people keep their homes too warm
(particularly their upstairs bedrooms). Studies show that the
optimal room temperature for sleep is actually between 60 to 68
degrees F, so adjust your thermostat (or use of blankets and fans)
accordingly.
Interestingly, while a cool room and a lower core temperature may
help you sleep better, cold hands and feet will not. Because blood
flow is a prime method of distributing heat evenly throughout your
body, if your extremities are cold it could be a sign of poor blood
flow, which results in sleeplessness. The solution for this is
simple: put on a pair of warm socks or place a hot water bottle near
your feet.
Quality Sleep Can Come Easy
Like healthy eating and exercise, getting high-quality sleep is
something that you can actively work at and improve in your life.
Proper "sleep hygiene" is important for both men and women to
achieve more restful, restorative sleep. I suggest you read through
my full set of
33 healthy sleep guidelines for all of the details. To start,
consider implementing the following changes:
Avoid watching TV or using your computer in the
evening,at least an hour or so before going to
bed. These devices emit blue light, which tricks your
brain into thinking it's still daytime. Normally, your brain
starts secreting melatonin between 9 p.m. and 10 p.m., and these
devices emit light that may stifle that process. Even the
American Medical Association now states:16
"… [N]ighttime electric light can disrupt circadian
rhythms in humans and documents the rapidly advancing
understanding from basic science of how disruption of
circadian rhythmicity affects aspects of physiology with
direct links to human health, such as cell cycle regulation,
DNA damage response, and metabolism."
Make sure you get BRIGHT sun exposure regularly.
Your pineal gland produces melatonin roughly in approximation to
the contrast of bright sun exposure in the day and complete
darkness at night. If you are in darkness all day long, it can't
appreciate the difference and will not optimize your melatonin
production.
Sleep in complete darkness, or as close to it as
possible. The slightest bit of light in your bedroom
can disrupt your body's clock and your pineal gland's melatonin
production. Even the tiniest glow from your clock radio could be
interfering with your sleep, so cover your radio up at night or
get rid of it altogether.
Move all electrical devices at least three feet away from
your bed. You may want to cover your windows with drapes or
blackout shades. If this isn't possible, wear an eye mask.
Install a low-wattage yellow, orange or red light
bulb if you need a source of light for navigation at night.
Light in these bandwidths does not shut down melatonin
production in the way that white and blue bandwidth light does.
Salt lamps are handy for this purpose. You can also download a
free application called F.lux that automatically dims your
monitor or screens.17
Avoid using loud alarm clocks. Being jolted
awake each morning can be very stressful. If you are regularly
getting enough sleep, you might not even need an alarm.
Get some sun in the morning, if possible.
Your circadian system needs bright light to reset itself. Ten to
15 minutes of morning sunlight will send a strong message to
your internal clock that day has arrived, making it less likely
to be confused by weaker light signals during the night. More
sunlight exposure is required as you age.
Maintain a regular sleep schedule. You
should go to bed and wake up at the same times each day, even on
the weekends. This will help your body to get into a sleep
rhythm and make it easier to fall asleep and get up in the
morning.
Establish a bedtime routine. This could
include meditation, deep breathing, using
aromatherapy or essential oils or indulging in a massage
from your partner. The key is to find something that makes you
feel relaxed, then repeat it each night to help you release the
tensions of the day.
If you can't sleep, don't stay in bed.
Lying in bed trying to sleep is frustrating and can create
anxiety. If you can't fall asleep, leave your bed and listen to
some soft music or read a book until you feel sleepy, then go
back to bed and try again.
Be mindful of electromagnetic fields (EMFs) in your
bedroom. EMFs can disrupt your pineal gland and its
melatonin production, and may have other negative biological
effects as well. A gauss meter is required if you want to
measure
EMF levels in various areas of your home. Ideally, you
should turn off any wireless router while you are sleeping. You
don't need the Internet on when you are asleep.