How Dangerous Is Sleep Deprivation, Really?

March 27, 2014
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What Happens When You’re Sleep Deprived? Three Primary Risks

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:¹

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.²
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,³ which may help explain why lack of sleep is tied to an increased risk of numerous chronic diseases.

Poor Sleep Linked to Chronic Disease, Widespread Pain, and Weight Gain

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. For example, during sleep your brain cells also shrink by about 60 percent, which allows for more efficient waste removal.⁴

Sleep is also intricately tied to important hormone levels, including melatonin, production of which is disturbed by lack of sleep. This is extremely problematic, as melatonin inhibits the proliferation of a wide range of cancer cell types, as well as triggers cancer cell apoptosis (self-destruction).

Lack of sleep also decreases levels of your fat-regulating hormone leptin while increasing the hunger hormone ghrelin. The resulting increase in hunger and appetite can easily lead to overeating and weight gain.

So as you can imagine, disruptions to sleep tend to cascade outward throughout your entire body. There’s a lot we still don’t know, but increasingly more that we do. For example, poor or insufficient sleep was found to be the strongest predictor for pain in adults over 50.⁵

Separate research also found that when participants cut their sleep from 7.5 to 6.5 hours a night, there were increases in the expression of genes associated with inflammation, immune excitability, diabetes, cancer risk, and stress.⁶

From the results of this study, it appears as though sleeping for an extra hour, if you're getting less than seven hours of sleep a night, may be a simple way to boost your health. But the opposite also holds true in that getting just one hour less sleep a night may raise your risk of multiple chronic diseases. Interrupted or impaired sleep can also:

Increase your risk of heart disease and cancer
Harm your brain by halting new neuron production. Sleep deprivation can increase levels of corticosterone (a stress hormone), resulting in fewer new brain cells being created in your hippocampus
Contribute to a pre-diabetic, insulin-resistant state, making you feel hungry even if you've already eaten, which can lead to weight gain
Contribute to premature aging by interfering with your growth hormone production, normally released by your pituitary gland during deep sleep (and during certain types of exercise, such as high-intensity interval training)
Increase your risk of dying from any cause

Daylight Saving Time Might Wreak Havoc on Your Health

Your circadian rhythm is very sensitive to changes, such that even the small amount of sleep deprivation caused by Daylight Saving Time may be problematic. One Washington University neuroscientist told CBS News that adjusting clocks forward one hour corresponds with a significant increase in traffic accidents and heart attacks⁷ over the next two to three days.⁸

One study also found that the spring transition, which causes a phase advance, is particularly hard on the average person’s sleep-wake cycle,⁹ and while it’s generally thought that the loss of one hour of sleep on the night of the change is inconsequential, research suggests otherwise. According to a report in Sleep Medicine Reviews:¹⁰

“…data suggests that increased sleep fragmentation and sleep latency present a cumulative effect of sleep loss [following the spring transition], at least across the following week, perhaps longer.

The autumn transition is often popularized as a gain of 1 h[our] of sleep but there is little evidence of extra sleep on that night. The cumulative effect of five consecutive days of earlier rise times following the autumn change again suggests a net loss of sleep across the week. Indirect evidence of an increase in traffic accident rates, and change in health and regulatory behaviors which may be related to sleep disruption suggest that adjustment to daylight saving time is neither immediate nor without consequence.”

Case in point, research also shows that Daylight Saving Time lead to increases in workplace injuries (frequency and severity)¹¹ as well as delays in reaction time that affect performance.¹² The latter study pointed out that small shifts in circadian timing occur all the time, not only due to Daylight Saving Time but also to changes such as sleeping in on a Saturday. The researchers concluded:

“These results add to previous reports that suggest that humans may be sensitive to commonly occurring small shifts in circadian timing.”

Tinkering with Time Comes with a Price

If adjusting your sleep-wake cycle by one hour twice a year for Daylight Saving Time, or simply sleeping in over the weekend, can disrupt your health, then imagine what traveling through different time zones or working the night shift can do. In one study published in Proceedings of the National Academy of Sciences (PNAS), researchers changed the participants' sleep patterns so they were about 12 hours out of sync in order to simulate the effects of jet lag or working the night shift.¹³ When blood tests were given, the results showed abnormally decreased gene expression, with up to one-third of participants' genes measurably altered by the disrupted sleep cycles.

Such disruptions have already been linked to heart disease, obesity, diabetes, cancer, and other chronic health conditions, raising serious concerns for people who regularly sleep during the day and/or stay awake at night. This includes not only those working the night shift but also frequent travelers (jet lag), college students, regular daytime nappers, and late night owls.

The problem is that, in the 21st century, many people ignore their body's internal clocks, either by necessity (working the night shift or remotely with co-workers across the globe) or choice (staying up late surfing the Web or watching TV). The quandary has some asking whether we should switch to a global Greenwich Mean Time, allowing everyone to honor their body’s clock but have one universal world time.

For the latter to work, economist Steve Hanke from Johns Hopkins University explained to CNN, everyone would “read the same time on their watches” but you might rise in the morning at 11 am instead of 6.¹⁴ Already, people are pushing the limits of their body clocks, getting up early and staying up late for a myriad of reasons. These reasons, it turns out, may not be worth it when it comes to your long-term health. As Dr. Gari Clifford, who studies sleep disorders at Emory University, told CNN:¹⁵

"The more important question is not 'Should we merge the current time zones?' but ‘What time should we be encouraging people to get up in relation to sunrise and sunset and how can we discourage exposure to artificial light in the evenings?’ Many of us are guilty of trying to pack too much into the day at both ends, but we suffer for it in the long term."

How to Support Your Circadian Rhythm and Sleep Better for Optimal Health

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 and 10 pm, and these devices emit light that may stifle that process. Even the American Medical Association now states:¹⁶

“…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.¹⁷
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.