By Dr. Mercola
Earlier this year, the Labor Statistics Bureau released data that stated Americans get an average of nearly nine hours of sleep per night.1 This seems high, considering most other surveys suggest Americans are largely sleep deprived.
And if the data relied on Americans’ notoriously inaccurate self-reporting their sleep time each night, it is seriously flawed. Most people calculate their sleep time by counting the hours from the time they went to bed until they wake up in the morning.
Using that approach does not actually factor the time it takes to fall asleep or the number of times one awakens every night. So this estimate will typically be off by 30-60 minutes or more. I am speaking from personal experience having used the Jawbone UP24 since the more accurate Zeo sleep-monitoring system went out of business.
When you use a fitness-tracking wristband device such as Jawbone UP or any of the many other similar products on the market, you can get a much more accurate picture of how much you’re actually sleeping.
You might be surprised to learn that your seven hours a night is really closer to six because you woke up multiple times and took 20 minutes to fall asleep initially. When Jawbone analyzed data for tens of thousands of Americans in 21 US cities, they indeed found that Americans may be sleeping much less than the Labor Statistics Bureau suggested.
Average Sleeping Time in Large US Cities? 6.8 Hours a Night
Sleep times in the 21 largest cities in the US were remarkably similar, ranging from a low of 6.82 hours in Houston, Texas to a high of 6.93 hours in Orlando, Florida. On average, that’s just over 6.8 hours of sleep a night.2
These results are close to those of the 2013 International Bedroom Poll by the National Sleep Foundation, which found, on average, Americans get only 6.5 hours of sleep on weeknights (but report needing 7.25 hours in order to function optimally).3 Although I seek to get 8 hours of sleep, my Jawbone UP typically records me at 7:30 to 7:45.
So how much sleep do you really need? There is no perfect answer to this question because like most everything else, the answer depends on a large number of highly individual factors. The general consensus seems to be that most people need somewhere between six and eight hours of sleep each night.
There's compelling research indicating that sleeping less than six hours may increase your insulin resistance and risk of diabetes. And studies show that less than five hours of sleep at night can double your risk of being diagnosed with angina, coronary heart disease, heart attack, or stroke. Interestingly enough, the same appears to be true when you sleep more than nine hours per night.
Dr. Rubin Naiman -- a clinical psychologist, author, teacher, and a leader in integrative medicine approaches to sleep and dreams -- recommends you simply sleep "enough hours so that your energy is sustained through the day without artificial stimulation, with the exception of a daytime nap," which he believes you are biologically programmed for.
I agree with this functional description rather than trying to come up with a specific numeric range. I would add to that guideline, however, the suggestion to watch out for physical or biological symptoms.
Pay attention to clues your body may be giving you. For instance, if you need an alarm clock to wake up, and you wake up feeling tired and groggy, you probably need to go to sleep earlier (or get more restful sleep).
It’s also said that if you fall asleep within a few minutes of your head hitting the pillow, you’re probably sleep deprived. A well-rested person will take about 10-15 minutes to fall asleep at night.4
That is an interesting factoid as I find it is true in my own life. Now that I get more sleep, it takes at least that amount of time to fall asleep. For many decades, I would only get 6 hours or less of sleep and would easily fall asleep in minutes. So don’t make the mistake I did and try to get by on minimal sleep.
Poor Sleep May Increase Suicide Risk in Older Adults
Poor sleep can actually impact virtually every aspect of your health, and the reason for this is your circadian rhythm (sleep-wake cycle) actually "drives" the rhythms of biological activity at the cellular level.
We’re only beginning to uncover the fascinating biological processes that take place during sleep, and the consequences that arise when you don’t get enough. Recent research revealed, for instance, that older adults with poor sleep quality may have an increased risk for suicide.
Both poor sleep and suicide rise with age, and the study found that older adults who reported poor sleep had a 1.4 times increased risk for suicide – an increase that persisted after controlling for the effects of a depressed mood.5
There are many reasons why the elderly may be at increase risk of poor sleep and its related problems. For instance, lack of magnesium may play a role in insomnia, and dietary surveys suggest that the majority of Americans are simply not getting enough magnesium from their diet alone.
Older adults, in particular, are more likely to be magnesium deficient because absorption decreases with age, and the elderly are more likely to take medications that can interfere with absorption (or interfere with sleep directly).
As you get older, your body’s internal clock also 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 Health issues, such as frequent urination or pain, can also keep seniors up at night, as can sleep apnea, which carries risks of its own.
Sleep Apnea Linked to High Blood Pressure That’s Resistant to Treatment
Sleep apnea is the inability to breathe properly, or the limitation of breath or breathing, during sleep. There are three general types of apnea described in the literature:
- Central apnea, which typically relates to your diaphragm and chest wall and an inability to properly pull air in
- Obstructive apnea, which relates to an obstruction of your airway that begins in your nose and ends in your lungs
- Mixed apnea is a combination of both
Obstructive sleep apnea consists of the frequent collapse of the airway during sleep, making it difficult for victims to breathe for periods lasting as long as 10 seconds. Those with a severe form of the disorder have at least 30 disruptions per hour. Not only do these breathing disruptions interfere with sleep, leaving you unusually tired the next day, it also reduces the amount of oxygen in your blood, which can impair the function of internal organs and/or exacerbate other health conditions you may have.
Recent research found, for instance, that severe obstructive sleep apnea may contribute to poor blood pressure control, even when medications are used.7 The study revealed that 58 percent of people with severe sleep apnea had treatment-resistant high blood pressure compared to fewer than 29 percent of those with moderate sleep apnea.8
If you have mild to moderate sleep apnea, orofacial myofunctional therapy may be the most profound therapy available. Myofunctional therapy is the “neuromuscular re-education or re-patterning of the oral and facial muscles.” The therapy includes facial and tongue exercises and behavior modification techniques to promote proper tongue position, improved breathing, chewing, and swallowing. Proper head and neck postures are also addressed. To learn more, please see my interview with Joy Moeller, a leading expert in this form of therapy in the US.
What Happens When You’re Sleep Deprived?
Research tells us that lack of sleep can contribute to everything, from diabetes, obesity, and heart disease to physical aches and pains and irreversible brain damage. In one recent animal study, sleep-deprived mice lost 25 percent of the neurons located in their locus coeruleus, a nucleus in the brainstem associated with wakefulness and cognitive processes.9 The research also showed that "catching up" on sleep on the weekend will not prevent this damage.
Other research published in the journal Neurobiology of Aging suggests that people with chronic sleep problems may develop Alzheimer's disease sooner than those who sleep well.10 And other research shows that sleeping less than six hours per night more than triples your risk of high blood pressure, and women who get less than four hours of shut-eye per night double their chances of dying from heart disease.11 What makes sleep deprivation so detrimental is that it doesn’t just impact one aspect of your health… it impacts many. Among them are three major risks to your mental and physical well-being:12
- Reaction Time Slows: When you’re sleep-deprived, you’re not going to react as quickly as you normally would, making driving or other potentially dangerous activities, like using power tools, risky. One study even found that sleepiness behind the wheel was nearly as dangerous as drinking and driving.13
- Your Cognition Suffers: Your ability to think clearly is also dampened by lack of sleep. If you’re sleep-deprived, you will have trouble retaining memories, processing information, and making decisions. This is why it’s so important to get a good night’s sleep prior to important events at work or home.
- Emotions Are Heightened: As your reaction time and cognition slows, your emotions will be kicked into high gear. This means that arguments with co-workers or your spouse are likely and you’re probably going to be at fault for blowing things out of proportion.
Meanwhile, previous research has found that sleep deprivation has the same effect on your immune system as physical stress or illness,14 which may help explain why lack of sleep is tied to an increased risk of numerous chronic diseases.
If You’re Tired, You Probably Need to Go to Bed Earlier
It sounds obvious, doesn’t it? And your mother probably told you this many times when you were a teenager, yet many of us still fight our body’s signals and stay up later than we should. According to the Jawbone data, the average bedtime for New Yorkers is 11:15 p.m. – and that’s earlier on average than people in other parts of the nation. Since most people have a set time when they must wake up, if you need more sleep, the solution is simple: turn off your TV, your cell phone, your computer, and your tablet… and go to sleep early. Try it for a night or two and you might be amazed at how rested you feel.
According to the 2014 Sleep in America Poll, 53 percent of respondents who turn electronics off while sleeping rate their sleep as excellent, compared to just 27 percent of those who leave their devices on.15 The blue light emitted from electronics such as TVs and computers suppresses your melatonin production, thereby preventing you from feeling sleepy. What you may not realize is that even if you don't feel sleepy, you need sleep. You've simply artificially disrupted your body clock; you have not in any way altered your body's biological needs. As noted by Oxford University Professor Russell Foster:16
"We are the supremely arrogant species; we feel we can abandon four billion years of evolution and ignore the fact that we have evolved under a light-dark cycle. And long-term, acting against the clock can lead to serious health problems."
Whether you’d like to acknowledge it or not, your body is programmed to rise with the sun and sleep when it’s dark, and maintaining a natural rhythm of exposure to sunlight during the day and darkness at night is one crucial foundational component of sleeping well. This was addressed in an interview 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.
The reason why light exposure during the daytime is so important is because it serves as the major synchronizer of your master body clock. This master clock is a group of cells in your brain called the suprachiasmatic nuclei (SCN). As a group, these nuclei synchronize to the light-dark cycle of your environment when light enters your eye. You also have other biological clocks throughout your body, and those clocks subsequently synchronize to your master clock.
To maintain healthy master clock timing, aim to adjust your light exposure to a more natural light rhythm, where you get bright light exposure during the day and limited blue light and bright light exposure once the sun sets. Pardi recommends getting at least 30-60 minutes of outdoor light exposure during daylight hours, in order to "anchor" your master clock rhythm. The ideal time to go outdoors is right around solar noon but any time during daylight hours is useful. Once the sun has set, the converse applies. Now, you want to avoid light as much as possible, in order for your body to secrete melatonin, which helps you feel sleepy.
My Top ‘Secrets’ for a Good Night’s Sleep
Making small adjustments to your daily routine and sleeping area can go a long way to ensure uninterrupted, restful sleep and, thereby, better health. I suggest you read through my full set of 33 healthy sleep guidelines for all of the details, but 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 pm and 10 pm, and these devices emit light that may stifle that process. Even the American Medical Association now states:17 “…nighttime 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. Even 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.
- 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.18
- Keep the temperature in your bedroom no higher than 70 degrees F. Many people keep their homes too warm (particularly their upstairs bedrooms). Studies show that the optimal room temperature for sleep is between 60 to 68 degrees F.
- Take a hot bath 90 to 120 minutes before bedtime. This increases your core body temperature, and when you get out of the bath it abruptly drops, signaling your body that you are ready to sleep.
- 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.
- 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.