The Effects of Sleep Deprivation on Your Body

“Read more about the short and long-term effects of sleep deprivation.”

— Dr. Dale

From The Effects of Sleep Deprivation on Your Body  

If you’ve ever spent a night tossing and turning, you already know how you’ll feel the next day — tired, cranky, and out of sorts. But missing out on the recommended 7 to 9 hours of shut-eye nightly does more than make you feel groggy and grumpy. The long term effects of sleep deprivation are real. It drains your mental abilities and puts your physical health at real risk. Science has linked poor slumber with all kinds of health problems, from weight gain to a weakened immune system. 

Your body needs sleep, just as it needs air and food to function at its best. During sleep, your body heals itself and restores its chemical balance. Your brain forges new connections and helps memory retention. Without enough sleep, your brain and body systems won’t function normally. It can also dramatically lower your quality of life. A review of 16 studies found that sleeping for less than 6 to 8 hours a night increases the risk of early death by about 12 percent.The obvious signs of sleep deprivation are:

• excessive sleepiness
• yawning
• irritability
• daytime fatigue

Stimulants like caffeine aren’t enough to override your body’s profound need for sleep. Behind the scenes, chronic sleep deprivation can interfere with your body’s internal systems and cause more than just the initial signs and symptoms listed above. Read on to learn exactly how sleep deprivation affects specific body functions and systems.

Central nervous system

Your central nervous system is the information highway of your body. Sleep is necessary to keep it functioning properly, but chronic insomnia can disrupt how your body usually sends information.During sleep, pathways form between nerve cells (neurons) in your brain that help you remember new information you’ve learned. Sleep deprivation leaves your brain exhausted, so it can’t perform its duties as well. You may also find it more difficult to concentrate or learn new things. The signals your body sends may also come at a delay, decreasing your coordination skills and increasing your risks for accidents. Sleep deprivation also negatively affectsyour mental abilities and emotional state. You may feel more impatient or prone to mood swings. It can also compromise decision-making processes and creativity.If sleep deprivation continues long enough, you could start having hallucinations—seeing or hearing things that aren’t there. A lack of sleep can also trigger mania in people who have manic depression. Other psychological risks include:

• impulsive behavior
• depression
• paranoia
• suicidal thoughts

You may also end up experiencing microsleep in the day. During these episodes, you’ll fall asleep for a few seconds or minutes without realizing it. Microsleep is out of your control and can be extremely dangerous if you’re driving. It can also make you more prone to injury due to trips and falls. 

Immune system

While you sleep, your immune system produces protective, infection-fighting substances like cytokines. It uses these substances to combat foreign invaders such as bacteria and viruses. Cytokines also help you sleep, giving your immune system more energy to defend your body against illness.Sleep deprivation prevents your immune system from building up its forces. If you don’t get enough sleep, your body may not beable to fend off invaders. It may also take you longer to recover from illness. Long-term sleep deprivation also increases your risk for chronic illnesses like diabetes and heart disease.

Respiratory system

The relationship between sleep and the respiratory system goes both ways. A night time breathing disorder called obstructive sleep apnea (OSA) can interrupt your sleep and lower the quality of your sleep. As you wake up throughout the night, this can cause sleep deprivation, which leaves you more vulnerable to respiratory infections like the common cold and flu. Sleep deprivation can also make existing respiratory diseases worse, such as chronic lung illness.

Digestive system

Along with eating too much and not exercising, sleep deprivation is another risk factor for overweight and obesity. Sleep affects the levels of two hormones, leptin and ghrelin, which control feelings of hunger and fullness. Leptin tells your brain that you’ve had enough to eat. Without enough sleep, your brain reduces leptin and raises ghrelin, which is an appetite stimulant. The flux of these hormones could explain nighttime snacking or why someone may overeat later in night. A lack of sleep can also contribute to weight gain by making you feel too tired to exercise.Sleep deprivation also prompts your body to release higher levels of insulin after you eat. Insulin controls your blood sugar level. Higher insulin levels promote fat storage and increase your risk for type 2 diabetes.

Cardiovascular system

Sleep affects processes that keep your heart and blood vessels healthy, including your blood sugar, blood pressure, and inflammation levels. It also plays a vital role in your body’s ability to heal and repair the blood vessels and heart.People who don’t sleep enough are more likely to get cardiovascular disease. One analysis published in the European Journal of Preventive Oncology linked insomnia to an increased risk of heart attack and stroke.

Endocrine system

Hormone production is dependent on your sleep. For testosterone production, you need at least three hours of uninterrupted sleep, which is about the time of your first REM episode. Waking up throughout the night could affect hormone production.This interruption can also affect growth hormone production, especially in children and adolescents. These hormones help build muscle mass and repair cells and tissues. The pituitary gland releases growth hormones continuously, but sleep and exercise also help induce the release of this hormone.

You Asked: How Can I Use More of My Brain?

“Here’s some advice on how to avoid distractions and stay focused throughout the day.”

— Dr. Dale

From You Asked: How Can I Use More of My Brain? 

It’s a myth that humans only use 10% of their brains. “That idea is not only inaccurate, it doesn’t make any sense,” says Earl Miller, a professor of neuroscience at the Picower Institute for Learning and Memory at the Massachusetts Institute of Technology. "Even the simplest behaviors engage much of our brain."

But while that old 10% dictum is bogus, it’s true that many of us have some untapped reserves of mental acuity that, if harnessed, could sharpen our powers of insight and analysis. The key to accessing those reserves, Miller says, is to stay focused. “The main thing that impedes our cognition is distraction."

Distractions are powerful drains on the brain's ability to focus, and one of the best ways to get more from your mind is to give yourself the gift of uninterrupted stretches of time.

Think of your mind as a muscle that can be strengthened with exercise. But the latest science suggests that "exercise" doesn't mean app-based brain games or activities like Sudoku, but bouts of prolonged, uninterrupted concentration, Miller says. Put simply, a distracted brain is a dumb brain. Unfortunately, “our brains are curious and are always interested in what’s going on around us, so it’s very hard to ignore all that and to stay focused."

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Distractions are ubiquitous, popping up as email alerts, text messages and social network updates. “People think that they can multitask and check these things without losing their focus, but we have lots of studies showing that task-switching leads to mistakes and back-tracking, and that it wastes a lot of time,” Miller says. And all of these interruptions seem to be getting in the way of more creative, profound insights. When your brain is bombarded by distraction, “your thoughts are more superficial, and you’re not getting as far down that path to where new ideas emerge."

Other experts agree. Switching between tasks can result in a phenomenon called “attention residue,” according to the work of Sophie Leroy, assistant professor of business at the University of Washington. When you ask your brain to quickly shift from one task to another, it struggles to cleanly discard the first and move on to the next. “Let’s say I work on a project right up until I have a meeting,” she says. “I may be at the meeting, but my brain is still trying to find closure on that project I was working on, so questions and ruminations about that project are interfering with my ability to concentrate.”

The more tasks you ask your brain to perform in a short period of time, the more that cognitive clutter accumulates, and the more your performance declines. Calvin Newport, associate professor of computer science at Georgetown University and author of the book Deep Work, puts that performance decline in real-world terms. “Anecdotally, it seems like most people experience a 50% drop in productivity and cognitive capacity when in a state of distraction,” he says. And even though a quick peek at your inbox or social feed only takes a second, "the duration of those checks does not correlate to the magnitude of the distraction,” Newport says.

Newport realized just how much those quick checks were tanking his brain’s performance when he wrote his last book. In an effort to be more productive, he started scheduling blocks of time to check his phone or email, while committing the rest of his day solely to his book or his research duties as an academic. “I should have had less time for my usual work because I was also researching and writing this book,” he says. “But the number of peer-reviewed papers I published that year went up by a factor of two.”

One of the best ways to sharpen your focus—and therefore enhance your brainpower—is to schedule this sort of uninterrupted time to focus on the cognitive tasks that matter to you. “It’s not uncommon for people who do this to talk about their productivity increasing,” Newport says. Research suggests that meditation may be another way to strengthen your brain’s ability to concentrate.

It's also important to complete one mental task before moving on to another. “If you have a meeting at 11, most of us will work until 10:59 and then rush to the meeting,” Leroy says. “That doesn’t give the brain time to figure out what it’s accomplished or what else needs to be done, and so there’s no closure.” Your brain needs that closure, she says, in order to transition effectively to its next chore.

She recommends taking some time between mental tasks—even a minute or two—to consider the work your brain just performed. "Write down where you are and what you want to do when you return to the task,” she says. In one of her experiments, people who followed this protocol improved their performance on a decision-making test by 79%, compared to people who hadn’t taken any time to collect their thoughts between tasks.

Another simple-sounding—yet challenging—recommendation is to inject more boredom into your life. “Don’t pull out the phone when standing in line, and if you’re sitting alone somewhere, try it without looking at a screen,” Newport says. Most of us need these breaks if we hope to stay focused on anything for longer than a few minutes. “The brain has to be comfortable not getting some shiny new stimuli from a device every few seconds," he says.

Indeed, a little digital break goes a long way. “I think being connected all the time is a lot like sugar: it’s easy for us to get accustomed to it and to want more,” Leroy says. “If you’ve been spending a lot of time multitasking, it’s going to take time to teach your brain to maintain focused attention."

We're Doing Something About Colorectal Cancer Disparities

“An interesting read about Colorectal Cancer disparities and what is being done about it.”

— Dr. Dale

From We're Doing Something About Colorectal Cancer Disparities  

Screening for colorectal cancer is a true public health success story. According to the most recent data from the Centers for Disease Control and Prevention (CDC), rates of screening for colorectal cancer have increased dramatically over the past two decades. That means that we are preventing more colorectal cancers and picking up many more in the earliest stages, when treatment may be more successful.

Although fewer people are being screened for colorectal cancer screening than we would like, improved screening rates are proof positive that research and outreach can and does have a big impact on people’s lives.

But there is another part of this story that is equally important but is cause for concern rather than celebration. Our progress against colorectal cancer has not been experienced equally.

African Americans, for example, have higher rates of new colorectal cancer cases and deaths than all other racial and ethnic groups. And although colorectal cancer is the fourth most common cancer overall, it’s the second most common cancer among Hispanics. Underlying these statistics, in part at least, is another well documented disparity.

Although widely accepted screening recommendations call for most people to be screened for colorectal cancer once they reach age 50, screening rates are lowest among those with lower education and income, Hispanics, American Indians/Alaska Natives, and people in rural areas. Screening rates are also low in people who are new or recent immigrants to the United States.

In short, the colorectal cancer disparities gap is significant, and the evidence that colorectal cancer screening saves lives is well documented. So we’re taking concrete steps to increase screening rates and, in so doing, alter the story line.

Earlier this year, the National Cancer Institute (NCI) launched an initiative called Screen to Save that aims to increase colorectal cancer screening rates among men and women age 50–75 from racially and ethnically diverse populations and in rural areas.

As part of this initiative, NCI-sponsored community health educators from 44 different institutions nationwide are fanning out in diverse communities across the country to educate people about the benefits of colorectal cancer screening. These educators are using evidence-based, proven strategies and tactics for motivating people who live in underserved communities to get screened.

Because we know that certain culturally-tailored outreach methods work better in specific communities and populations than in others, educators are using only those methods that have been proven to work, saving time and money. Community hospitals and clinics can incorporate these tools and techniques into their education and outreach arsenal to increase colorectal cancer screening among the communities they serve.

Effective techniques for improving screening don’t have to be fancy or expensive. For example, a recent study showed that sending text message reminders about colorectal cancer screening substantially improved screening rates in American Indian and Alaskan Native women. Another recent study showed that simply providing written information about the fecal immunohistochemical test, or FIT kit—an effective, but often overlooked, screening test for colorectal cancer—to African Americans age 50 and older increased their screening rates.

The latest data, in fact, show that, when it comes to screening for colorectal cancer, rates among African Americans have nearly caught up to the rates among White Americans. Now our challenge is to further accelerate that trend and replicate it in other populations where rates continue to lag.

NCI, CDC, and professional societies, like the American Cancer Society have supported research aimed at addressing cancer health disparities for years, and have laid the foundation for national programs such as NCI’s Screen to Save.

Moving forward, NCI and its partners―including national organizations and smaller, local nonprofits―hope to expand this program to include a larger network of hospitals and clinics that can identify people who are eligible for screening and can provide the appropriate follow-up and linkages to needed care for those who undergo screening.

This is a unique opportunity to help reduce the number of deaths from colorectal cancer. Because the best way to continue the progress we’ve made against this cancer over the past 20 years is to ensure that everybody who should be screened has the opportunity, knowledge, and resources to do so.