7-8 hours of sleep improves health

 

Credit: © Brian Jackson / stock.adobe.com

Less than five hours' sleep a night linked to higher risk of multiple diseases

Date:

October 19, 2022

Source:

University College London

Summary:

Getting less than five hours of sleep in mid-to-late life could be linked to an increased risk of developing at least two chronic diseases, finds a new study.

Getting less than five hours of sleep in mid-to-late life could be linked to an increased risk of developing at least two chronic diseases, finds a new study led by UCL researchers.

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The research, published in PLOS Medicine, analysed the impact of sleep duration on the health of more than 7,000 men and women at the ages of 50, 60 and 70, from the Whitehall II cohort study.

Researchers examined the relationship between how long each participant slept for, mortality and whether they had been diagnosed with two or more chronic diseases (multimorbidity) -- such as heart disease, cancer or diabetes -- over the course of 25 years.

People who reported getting five hours of sleep or less at age 50 were 20% more likely to have been diagnosed with a chronic disease and 40% more likely to be diagnosed with two or more chronic diseases over 25 years, compared to people who slept for up to seven hours.

Additionally, sleeping for five hours or less at the age of 50, 60, and 70 was linked to a 30% to 40% increased risk of multimorbidity when compared with those who slept for up to seven hours.

Researchers also found that sleep duration of five hours or less at age 50 was associated with 25% increased risk of mortality over the 25 years of follow-up -- which can mainly be explained by the fact that short sleep duration increases the risk of chronic disease(s) that in turn increase the risk of death.

Lead author, Dr Severine Sabia (UCL Institute of Epidemiology & Health, and Inserm, Université Paris Cité) said: "Multimorbidity is on the rise in high income countries and more than half of older adults now have at least two chronic diseases. This is proving to be a major challenge for public health, as multimorbidity is associated with high healthcare service use, hospitalisations and disability.

"As people get older, their sleep habits and sleep structure change. However, it is recommended to sleep for 7 to 8 hours a night -- as sleep durations above or below this have previously been associated with individual chronic diseases.

"Our findings show that short sleep duration is also associated with multimorbidity.

"To ensure a better night's sleep, it is important to promote good sleep hygiene, such as making sure the bedroom is quiet, dark and a comfortable temperature before sleeping. It's also advised to remove electronic devices and avoid large meals before bedtime. Physical activity and exposure to light during the day might also promote good sleep."

As part of the study, researchers also assessed whether sleeping for a long duration, of nine hours or more, affected health outcomes. There was no clear association between long sleep durations at age 50 and multimorbidity in healthy people.

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Close the blinds during sleep to protect your health

Even moderate light exposure during sleep harms heart health and increases insulin resistance

Bedroom with full moon | Credit: © Brilliant Eye / stock.adobe.com

Summary:

Exposure to even moderate ambient lighting during nighttime sleep, compared to sleeping in a dimly lit room, harms your cardiovascular function during sleep and increases your insulin resistance the following morning, reports a new study. Just a single night of exposure to moderate room lighting during sleep can impair glucose and cardiovascular regulation, which are risk factors for heart disease, diabetes and metabolic syndrome.

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Close the blinds, draw the curtains and turn off all the lights before bed. Exposure to even moderate ambient lighting during nighttime sleep, compared to sleeping in a dimly lit room, harms your cardiovascular function during sleep and increases your insulin resistance the following morning, reports a new Northwestern Medicine study

"The results from this study demonstrate that just a single night of exposure to moderate room lighting during sleep can impair glucose and cardiovascular regulation, which are risk factors for heart disease, diabetes and metabolic syndrome," said senior study author Dr. Phyllis Zee, chief of sleep medicine at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. "It's important for people to avoid or minimize the amount of light exposure during sleep."

There is already evidence that light exposure during daytime increases heart rate via activation of the sympathetic nervous system, which kicks your heart into high gear and heightens alertness to meet the challenges of the day.

"Our results indicate that a similar effect is also present when exposure to light occurs during nighttime sleep," Zee said.

Heart rate increases in light room, and body can't rest properly

"We showed your heart rate increases when you sleep in a moderately lit room," said Dr. Daniela Grimaldi, a co-first author and research assistant professor of neurology at Northwestern. "Even though you are asleep, your autonomic nervous system is activated. That's bad. Usually, your heart rate together with other cardiovascular parameters are lower at night and higher during the day."

There are sympathetic and parasympathetic nervous systems to regulate our physiology during the day and night. Sympathetic takes charge during the day and parasympathetic is supposed to at night, when it conveys restoration to the entire body.

How nighttime light during sleep can lead to diabetes and obesity

Investigators found insulin resistance occurred the morning after people slept in a light room. Insulin resistance is when cells in your muscles, fat and liver don't respond well to insulin and can't use glucose from your blood for energy. To make up for it, your pancreas makes more insulin. Over time, your blood sugar goes up.

An earlier study published in JAMA Internal Medicine looked at a large population of healthy people who had exposure to light during sleep. They were more overweight and obese, Zee said.

"Now we are showing a mechanism that might be fundamental to explain why this happens," Zee said. "We show it's affecting your ability to regulate glucose."

The participants in the study weren't aware of the biological changes in their bodies at night.

Learn about your brain in clear, jargon-free language.

"But the brain senses it," Grimaldi said. "It acts like the brain of somebody whose sleep is light and fragmented. The sleep physiology is not resting the way it's supposed to."

Exposure to artificial light at night during sleep is common

Exposure to artificial light at night during sleep is common, either from indoor light emitting devices or from sources outside the home, particularly in large urban areas. A significant proportion of individuals (up to 40%) sleep with a bedside lamp on or with a light on in the bedroom and/or keep the television on.

Light and its relationship to health is double edged.

"In addition to sleep, nutrition and exercise, light exposure during the daytime is an important factor for health, but during the night we show that even modest intensity of light can impair measures of heart and endocrine health," Zee said.

The study tested the effect of sleeping with 100 lux (moderate light) compared to 3 lux (dim light) in participants over a single night. The investigators discovered that moderate light exposure caused the body to go into a higher alert state. In this state, the heart rate increases as well as the force with which the heart contracts and the rate of how fast the blood is conducted to your blood vessels for oxygenated blood flow.

"These findings are important particularly for those living in modern societies where exposure to indoor and outdoor nighttime light is increasingly widespread," Zee said.

Zee's top tips for reducing light during sleep

(1) Don't turn lights on. If you need to have a light on (which older adults may want for safety), make it a dim light that is closer to the floor.

(2) Color is important. Amber or a red/orange light is less stimulating for the brain. Don't use white or blue light and keep it far away from the sleeping person.

(3) Blackout shades or eye masks are good if you can't control the outdoor light. Move your bed so the outdoor light isn't shining on your face.

Is my room too light?

"If you're able to see things really well, it's probably too light," Zee said.

Story Source:

Materials provided by Northwestern University. Original written by Marla Paul. Note: Content may be edited for style and length.

Stressed to the max? Deep sleep can rewire the anxious brain

Learn how the brain controls stress. 

A sleepless night can trigger up to a 30 percent rise in emotional

stress levels, new study shows

:

November 4, 2019:

University of California - Berkeley

Researchers have found that the type of sleep most apt to calm and reset the anxious brain
is deep sleep, also known as non-rapid eye movement (NREM) slow-wave sleep, a state in
which neural oscillations become highly synchronized, and heart rates and blood pressure drop.

Deep sleep concept (stock image).

Credit: © stokkete / Adobe Stock

When it comes to managing anxiety disorders, William Shakespeare's
Macbeth had it right when he referred to sleep as the "balm of hurt minds."
While a full night of slumber stabilizes emotions, a sleepless night can trigger
up to a 30% rise in anxiety levels, according to new research from the
University of California, Berkeley.

UC Berkeley researchers have found that the type of sleep most apt to calm and reset
the anxious brain is deep sleep, also known as non-rapid eye movement (NREM) slow-wave
sleep, a state in which neural oscillations become highly synchronized, and heart rates and
blood pressure drop.

"We have identified a new function of deep sleep, one that decreases anxiety overnight
by reorganizing connections in the brain," said study senior author Matthew Walker,
a UC Berkeley professor of neuroscience and psychology. "Deep sleep seems to be a
natural anxiolytic (anxiety inhibitor), so long as we get it each and every night."

The findings, published today, Nov. 4, in the journal Nature Human Behaviour,
provide one of the strongest neural links between sleep and anxiety to date. They
also point to sleep as a natural, non-pharmaceutical remedy for anxiety disorders,
which have been diagnosed in some 40 million American adults and are rising among
children and teens.

"Our study strongly suggests that insufficient sleep amplifies levels of anxiety and,
conversely, that deep sleep helps reduce such stress," said study lead author
Eti Ben Simon, a postdoctoral fellow in the Center for Human Sleep Science at UC Berkeley.

In a series of experiments using functional MRI and polysomnography, among other measures,
Simon and fellow researchers scanned the brains of 18 young adults as they viewed
emotionally stirring video clips after a full night of sleep, and again after a sleepless night.
Anxiety levels were measured following each session via a questionnaire known as the
state-trait anxiety inventory.

After a night of no sleep, brain scans showed a shutdown of the
medial prefrontal cortex, which normally helps keep our anxiety in check,
while the brain's deeper emotional centers were overactive.

"Without sleep, it's almost as if the brain is too heavy on the emotional accelerator
pedal, without enough brake," Walker said.

After a full night of sleep, during which participants' brain waves were
measured via electrodes placed on their heads, the results showed their anxiety
levels declined significantly, especially for those who experienced more slow-wave
NREM sleep.

"Deep sleep had restored the brain's prefrontal mechanism that regulates our emotions,
lowering emotional and physiological reactivity and preventing the escalation of anxiety,"
Simon said.

Beyond gauging the sleep-anxiety connection in the 18 original study participants,
the researchers replicated the results in a study of another 30 participants.

Across all the participants, the results again showed that those who got more
nighttime deep sleep experienced the lowest levels of anxiety the next day.

Moreover, in addition to the lab experiments, the researchers conducted an
online study in which they tracked 280 people of all ages about how both their sleep and
anxiety levels changed over four consecutive days.

The results showed that the amount and quality of sleep the participants got from
one night to the next predicted how anxious they would feel the next day. Even subtle
nightly changes in sleep affected their anxiety levels.

"People with anxiety disorders routinely report having disturbed sleep, but rarely is
sleep improvement considered as a clinical recommendation for lowering anxiety,"
Simon said.

Learn how the brain controls stress. 

"Our study not only establishes a causal connection between sleep and anxiety, but it
identifies the kind of deep NREM sleep we need to calm the overanxious brain."

On a societal level, "the findings suggest that the decimation of
sleep throughout most industrialized nations and the marked escalation in anxiety
disorders in these same countries is perhaps not coincidental, but causally related,"
Walker said. "The best bridge between despair and hope is a good night of sleep."

Co-authors of the study are Aubrey Rossi and Allison Harvey, both at UC Berkeley.

---

Story Source:

Materials provided by University of California - Berkeley. Original written by Yasmin Anwar.

Does sleep boost memory, affect autism, Alzheimer's?

Learn more about your incredible brain.

Why do we feel great after a solid night's rest and crummy without one?

Are we "brainwashed" during sleep?
Cerebrospinal fluid washes in and out of brain during sleep

Date:

October 31, 2019

Source:

Boston University

Summary:

A new study illustrates that the brain's cerebrospinal fluid pulses during sleep, and that these motions are closely tied with brain wave activity and blood flow. It may confirm the hypothesis that CSF flow and slow-wave activity both help flush toxic, memory-impairing proteins from the brain.

FULL STORY

New research from Boston University suggests that tonight while you sleep, something amazing will happen within your brain. Your neurons will go quiet. A few seconds later, blood will flow out of your head. Then, a watery liquid called cerebrospinal fluid (CSF) will flow in, washing through your brain in rhythmic, pulsing waves.

New research from Boston University suggests that tonight while you sleep, something amazing will happen within your brain. Your neurons will go quiet. A few seconds later, blood will flow out of your head. Then, a watery liquid called cerebrospinal fluid (CSF) will flow in, washing through your brain in rhythmic, pulsing waves.

Learn more about your incredible brain.

"We've known for a while that there are these electrical waves of activity in the neurons," says study coauthor Laura Lewis, a BU College of Engineering assistant professor of biomedical engineering and a Center for Systems Neuroscience faculty member. "But before now, we didn't realize that there are actually waves in the CSF, too."

This research may also be the first-ever study to take images of CSF during sleep. And Lewis hopes that it will one day lead to insights about a variety of neurological and psychological disorders that are frequently associated with disrupted sleep patterns, including autism and Alzheimer's disease.

The coupling of brain waves with the flow of blood and CSF could provide insights about normal age-related impairments as well. Earlier studies have suggested that CSF flow and slow-wave activity both help flush toxic, memory-impairing proteins from the brain. As people age, their brains often generate fewer slow waves. In turn, this could affect the blood flow in the brain and reduce the pulsing of CSF during sleep, leading to a buildup of toxic proteins and a decline in memory abilities. Although researchers have tended to evaluate these processes separately, it now appears that they are very closely linked.

This research may also be the first-ever study to take images of CSF during sleep. And Lewis hopes that it will one day lead to insights about a variety of neurological and psychological disorders that are frequently associated with disrupted sleep patterns, including autism and Alzheimer's disease.

The coupling of brain waves with the flow of blood and CSF could provide insights about normal age-related impairments as well. Earlier studies have suggested that CSF flow and slow-wave activity both help flush toxic, memory-impairing proteins from the brain. As people age, their brains often generate fewer slow waves. In turn, this could affect the blood flow in the brain and reduce the pulsing of CSF during sleep, leading to a buildup of toxic proteins and a decline in memory abilities. Although researchers have tended to evaluate these processes separately, it now appears that they are very closely linked.

Learn more about your incredible brain.

Sleep is essential for business leaders seeking next successful venture

Your amazing brain in clear,
understandable English. Click here.

Date:

August 5, 2019

Source:

University of Central Florida

Summary:

The secret ingredient for coming up with great business ideas that can take off, may be something we can all tap into -- a good night's sleep. According to a new study, sleep plays an especially important role in not only identifying a good business idea, but in evaluating it and believing it is viable.

Businessman resting at desk (stock image).

Credit: © Syda Productions / Adobe Stock

Jeff Bezos and Arianna Huffington came up with brilliant ideas that turned into companies that are now household names -- Amazon and HuffPost. The secret ingredient for coming up with these ideas may be something we can all tap into -- a good night's sleep.

According to a new study, sleep plays an especially important role in not only identifying a good business idea, but in evaluating it and believing it is viable.

"Entrepreneurs who consistently choose hustle over sleep, thinking that sleep comes after success, may be subverting their efforts to succeed," says lead author Jeff Gish, an assistant business professor at the University of Central Florida. "Everyone needs a good night of sleep, but it is especially important for entrepreneurs."

The study was published in Journal of Business Venturing in late July.

Several studies have found a connection between sleep and job performance. Bezos and Huffington have both indicated they get plenty of sleep in various media interviews. But the new study found a link between sleep and the cognitive skills needed to identify and evaluate an idea. Entrepreneurs use experience and business knowledge to evaluate ideas that could turn into successful business ventures. But sleep appears to be an important factor as well.

The study surveyed more than 700 entrepreneurs from around the world. The surveys asked about sleep patterns, hours of sleep and types of sleep.

Business pitches were drafted and an independent panel of business experts reviewed and ranked the pitches as having the most potential, medium potential and least potential for success. Then the participants in the study reviewed the three pitches in the same day. Those leaders who had less sleep did not consistently pick the best pitches.

In the second part of the study, a smaller group of participants evaluated the pitches over several weeks while charting their sleep patterns. Those participants who had at least seven hours of sleep each night consistently selected the best pitches identified by the expert panel. Those who had less sleep or restless sleep did not consistently pick the best pitches.

"The evidence suggests that less sleep leads to less accurate beliefs about the commercial potential of a new venture idea," Gish says. "Since we compared individual performance over multiple days, we can say that these results are consistent even for entrepreneurs who don't sleep as much on average as the general population."

The study was completed at the University of Oregon, where Gish earned a doctorate in philosophy of management. Gish also holds a master's degree in engineering and technology management. Other collaborators on the study include: David T. Wagner from the University of Oregon, Denis A. Grégoire from HEC Montreal business school in Canada, and Christopher M. Barnes from the University of Washington.

A national sleep crisis: Pt. 1

Poor sleep impairs work and productivity, raises risks of car crashes, and may play a key role in risk for developing Alzheimer's disease.

It's serious stuff.

In this excerpt from Healing the Brain: Stress, Trauma and Development, we take a close look at sleep.

Get your copy today on Amazon and Kindle.

Fighting a National Sleep Crisis

Many people view sleep as merely a “down time” when their brains shut off and their bodies rest. People may cut back on sleep, thinking it won’t be a problem, because other responsibilities seem much more important. But research shows that a number of vital tasks carried out during sleep help people stay healthy and function at their best. While you sleep, your brain is hard at work forming the pathways necessary for learning and creating memories and new insights. Without enough sleep, you can’t focus and pay attention or respond quickly. A lack of sleep may even cause mood problems. Also, growing evidence shows that a chronic lack of sleep increases your risk of obesity, diabetes, cardiovascular disease, and infections.

Public Domain Pictures

Researchers acknowledge that regular, consistent sleep plays a major role in brain and body health

Despite growing support for the idea that adequate sleep, like adequate nutrition and physical activity, is vital to our well-being, people are sleeping less. The nonstop “24/7” nature of the world today encourages longer or nighttime work hours and offers continual access to entertainment and other activities. To keep up, people cut back on sleep. A common myth is that people can learn to get by on little sleep (such as less than 6 hours a night) with no adverse effects. Research suggests, however, that adults need at least 7–8 hours of sleep each night to be well rested. Indeed, in 1910, most people slept 9 hours a night. But recent surveys show the average adult now sleeps fewer than 7 hours a night.

Chronic sleep loss or sleep disorders may affect as many as 70 million Americans.

More than one-third of adults report daytime sleepiness so severe that it interferes with work, driving, and social functioning at least a few days each month. Evidence also shows that children’s and adolescents’ sleep is shorter than recommended. These trends have been linked to increased exposure to electronic media. Lack of sleep may have a direct effect on children’s health, behavior, and development. Chronic sleep loss or sleep disorders may affect as many as 70 million Americans. This may result in an annual cost of $16 billion in health care expenses and $50 billion in lost productivity.

What Makes You Sleep? Although you may put off going to sleep in order to squeeze more activities into your day, eventually your need for sleep becomes overwhelming. This need appears to be due, in part, to two substances your body produces. One substance, called adenosine, builds up in your blood while you’re awake. Then, while you sleep, your body breaks down the adenosine. Levels of this substance in your body may help trigger sleep when needed.

A buildup of adenosine and many other complex factors might explain why, after several nights of less than optimal amounts of sleep, you build up a sleep debt. This may cause you to sleep longer than normal or at unplanned times during the day. Because of your body’s internal processes, you can’t adapt to getting less sleep than your body needs. Eventually, a lack of sleep catches up with you. The other substance that helps make you sleep is a hormone called melatonin. This hormone makes you naturally feel sleepy at night. It is part of your internal “biological clock,” which controls when you feel sleepy and your sleep patterns. Your biological clock is a small bundle of cells in your brain that works throughout the day and night. Internal and external environmental cues, such as light signals received through your eyes, control these cells. Your biological clock triggers your body to produce melatonin, which helps prepare your brain and body for sleep. As melatonin is released, you’ll feel increasingly drowsy. 

Get your copy today on Amazon and Kindle.

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