By Dr. Mercola
If you have trouble sleeping, it could be a sign of an underlying health condition, including one you might not immediately associate with sleep problems — type 2 diabetes. Sleep difficulties such as insomnia affect your circadian rhythm, which in turn is regulated by hormones.
Many of the same hormones that affect your circadian rhythm also affect your metabolism and blood sugar control, which may explain why insomnia is a risk factor for diabetes (and the opposite also holds true in that diabetes is a risk factor for insomnia).1
For instance, sleep troubles are linked to excess release of the ghrelin hormone, which increases appetite, as well as the stress hormone cortisol, which is linked with insulin resistance.
A recent study published in the journal Diabetologia even found that women who have trouble falling or staying asleep all or most of the time have a 45 percent greater risk of type 2 diabetes than women without sleep problems.2
Numerous Sleep Problems May Quadruple Your Diabetes Risk
A number of sleep issues were associated with type 2 diabetes, including:
- Trouble falling or staying asleep
- Getting less than six hours of sleep a night
- Frequent snoring
- Sleep apnea
- Rotating shift work
Women who reported four or more of these sleep difficulties were more than four times as likely to develop type 2 diabetes than women with no sleep troubles. Those with two of the sleep problems had double the risk.
Dr. Frank B. Hu, a physician, researcher and professor of Nutrition and Epidemiology at Harvard, told The New York Times, “it’s not just quantity of sleep, but quality as well” that is associated with these health risks.”3
Poor Sleep May Impair the Way Your Body Responds to Insulin
Impaired insulin sensitivity, also known as insulin resistance, occurs when your body cannot use insulin properly, allowing your blood sugar levels to get too high. Insulin resistance is a precursor to type 2 diabetes as well as a risk factor in many other chronic diseases.
Poor diet, especially excessive intake of fructose, sugar and grains, along with a sedentary lifestyle are major risk factors for insulin resistance, but so, too, is poor sleep.
According to research published in the Annals of Internal Medicine, after four nights of sleep deprivation (sleep time of only 4.5 hours per night), study participants' insulin sensitivity was 16 percent lower.4
Meanwhile, their fat cells' insulin sensitivity was 30 percent lower and rivaled levels seen in those with diabetes or obesity. The study's senior author, Matthew Brady, Ph.D. an associate professor of medicine at the University of Chicago, told CNN: 5
"This is the equivalent of metabolically aging someone 10 to 20 years just from four nights of partial sleep restriction. Fat cells need sleep, and when they don't get enough sleep, they become metabolically groggy."
As mentioned, besides deteriorating your insulin sensitivity, sleep deprivation also increases levels of ghrelin, a hormone that triggers hunger. This can easily result in overeating and/or indulging in the wrong foods.
Too little sleep also impacts your levels of thyroid and stress hormones, which in turn can affect your memory, immune system, heart and metabolism and much more.
By altering the balance of all of these various hormones, lack of sleep can lead to a wide array of health problems, from accelerated aging and earlier onset of Alzheimer's to depression and increased risk for cancer.
3 Tricks for Better Sleep
The quality of your sleep matters just as much as the number of hours you spend in bed. The Vox video above shares three simple tricks to easily boost your sleep quality, echoing the sleep tips compiled in my 33 healthy sleep guidelines.
You can try the following to experience more restful sleep starting tonight:
1. Get the Temperature Right
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 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.6
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.
Professor Russell Foster, Ph.D. of the University of Oxford actually recommends ditching your pajamas to improve your slumber — which is preferred by one-third of U.S. adults anyway, according to one study.7
If you’re wearing lots of bedclothes, it may be more difficult for your body to regulate its temperature.
With or without pajamas, it’s important to make sure your hands and feet are warm because if they aren’t, the blood vessels near your skin constrict and reduce blood flow in an effort to prevent heat from escaping, and this prevents your core temperature from dropping easily.
Conversely, warming your skin causes your peripheral blood vessels to widen, promoting heat loss. To summarize, if you want to fall asleep easily, you’ll need to be warm enough that your blood vessels won’t constrict, but not so hot that your body can’t cool down.
The solution for this is simple: put on a pair of warm socks or place a hot water bottle near your feet. 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.
2. Darkness at Night, Bright Light During the Day
Ever since the advent of the light bulb, people have become increasingly “darkness deficient” at night, while simultaneously getting too little light during the day, courtesy of working indoors. Light intensity is measured in lux units, and on any given day, the outdoor lux units will be around 100,000 at noon. Indoors, the typical average is somewhere between 100 to 2,000 lux units — about two orders of magnitude less.
The brightness of the light matters, because 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 relative darkness all day long, it can't appreciate the difference and will not optimize your melatonin production, and that can have some rather significant ramifications for your health and sleep. As reported by Gizmodo:8
“The light — and the dark — are important signals for the cycle. This circadian rhythm has developed over three billion years as life evolved on Earth in the context of the sun’s day/night cycle. It is built deeply into our genetic makeup.
During the night, in the dark, body temperature drops, metabolism slows, and the hormone melatonin rises dramatically. When the sun comes up in the morning, melatonin has already started falling, and you wake up. This natural physiological transition into and out of night is of ancient origin, and melatonin is crucial for the process to proceed as it should.
If you were to put someone in a dark cave with no time cues at all, the cycle will last about 24 hours, but not exactly. Without time cues like those from the sun, eventually that person would become out of sync with people outside.”
Aside from lowering body temperature, slowing metabolism, and raising melatonin, your body also undergoes a number of other changes when in the dark. For example, levels of the satiety hormone leptin rise, which decreases feelings of hunger. Gene expression is also affected by your endogenous circadian clock, as is cellular growth and repair and hormone production.
Exposing yourself to light at night even briefly leads to the disruption of all of these processes, setting the stage for diseases like obesity, diabetes, cancer, and depression. The take-home message? Get exposure to bright light in the morning and during the day and turn off or dim lights (including those from electronics) at least one hour prior to bedtime.
3. Lavender Essential Oil
Keep a bottle of lavender essential oil by your bedside to sniff before dozing off. You can also add a few drops to a diffuser, rub in some lavender-infused body lotion, spritz it on your pillow or indulge in a lavender-infused sleep mask.
Lavender is well known for its calming effects. One study found lavender essential oil led to improvements in the length of time taken to fall asleep and severity of insomnia among female college students.9 Inhaling the scent of lavender together with improved sleep hygiene also led to improved sleep quality among college students with sleep issues — more so than improved sleep hygiene alone.10
Lavender bath oil even helps improve sleep in very young infants,11 and when lavender was diffused nightly into the rooms of patients suffering from dementia, anxiety and disturbed sleep patterns, nurses reported improvements in both insomnia and anxiety.12
Anecdotal Tips to Help You Get to Sleep
The Guardian recently asked readers to share their suggestions for a good night’s sleep.13 While not all of these are backed by science, they’ve received glowing testimonies and might help you to sleep better, too.
Sip orange peel tea (simply pour hot water over organic orange peels and enjoy about 20 minutes before bedtime) Listen to an audiobook (set a timer so it turns off after about 10 or 20 minutes) Put on thick, warm socks to keep your feet warm Tense your muscles and then relax them Avoid light one hour before bed Turn off the TV and read in bed Visualizations; one reader noted, “I always think of the desolate cold bleak moors in the rain and wind close to where I live, and I snuggle down and am safe and warm. Then I’m asleep.”14 Avoid alcohol before bedtime Exercise regularly
Do You Know How Much Sleep You’re Actually Getting?
According to the documentary Sleepless in America, 40 percent of Americans are sleep-deprived, with many getting less than five hours of sleep per night. Data from Withings, a maker of health-tracking devices, suggests the average American falls asleep at 11:32 pm and wakes up at 7:22 am, although there were variations according to state. For instance, New Yorkers tend to go to sleep later, at 11:54 pm, and rise later, at 7:36 am, than people in other states.15
It’s important for you to know, personally, how much sleep you get each night. Not just the time you spend in bed but the actual time you spend sleeping. Wearable fitness trackers are quite useful for this and you may be surprised at how many hours of sleep you actually get each 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.16 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 seven 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. And be sure to listen to your body; if you suffer from daytime sleepiness, fall asleep during meetings, or have a hard time getting out of bed in the morning, these are all signs that you probably need more sleep.
To accomplish this, many people need to first set a sleep goal of about eight hours in their mind and then make practical, logistic changes. If you have a set wake time (which is a good idea anyway) and you’re not able to squeeze in enough hours, you’ll need to adjust your schedule so you’re going to bed earlier. Turn off the TV, the computer and your phone, and commit to sleeping from a set bedtime that gives you about eight hours before you need to wake up.
And, again, if you’re unsure how many hours of sleep you’re getting each night, try a wearable fitness tracker like the Jawbone UP. It will monitor your actual time spent asleep so you can adjust your schedule accordingly. Proper “sleep hygiene” is also important, however, so to achieve more restful, restorative sleep I suggest you read through my full set of 33 healthy sleep guidelines for all of the details.