Beauty sleep could be real, say body clock biologists

Woman waking up from bed (stock image).

Biologists from The University of Manchester have explained for the first time why having a good night's sleep really could prepare us for the rigours of the day ahead.

The study in mice and published in Nature Cell Biology, shows how the body clock mechanism boosts our ability to maintain our bodies when we are most active.

And because we know the body clock is less precise as we age, the discovery, argues lead author Professor Karl Kadler, may one day help unlock some of the mysteries of aging.

The discovery throws fascinating light on the body's extracellular matrix -which provides structural and biochemical support to cells in the form of connective tissue such as bone, skin, tendon and cartilage.

Over half our body weight is matrix, and half of this is collagen -- and scientists have long understood it is fully formed by the time we reach the age of 17.

But now the researchers have discovered there are two types of fibrils -- the rope-like structures of collagen that are woven by the cells to form tissues.

Thicker fibrils measuring about 200 nanometres in diameter -- a million million times smaller than a pinhead -- are permanent and stay with us throughout our lives, unchanged from the age of 17.

But thinner fibrils measuring 50 nanometres, they find, are sacrificial, breaking as we subject the body to the rigours of the day but replenishing when we rest at night.

The collagen was observed by mass spectrometry and the mouse fibrils were observed using state of the art volumetric electron microscopy -- funded by the Wellcome Trust -- every 4 hours over 2 days.

When the body clock genes where knocked out in mice, the thin and thick fibrils were amalgamated randomly.

"Collagen provides the body with structure and is our most abundant protein, ensuring the integrity, elasticity and strength of the body's connective tissue," said Professor Kadler

"It's intuitive to think our matrix should be worn down by wear and tear, but it isn't and now we know why: our body clock makes an element which is sacrificial and can be replenished, protecting the permanent parts of the matrix.

He added: "So if you imagine the bricks in the walls of a room as the permanent part, the paint on the walls could be seen as the sacrificial part which needs to be replenished every so often.

"And just like you need to oil a car and keep its radiator topped up with water, these thin fibrils help maintain the body's matrix."

"Knowing this could have implications on understanding our biology at its most fundamental level. It might, for example, give us some deeper insight into how wounds heal, or how we age.

---

Story Source:

Materials provided by University of Manchester. Note: Content may be edited for style and length.

The Science of Sleep: A Brief Guide on How to Sleep Better Every Night

If you want to learn how to sleep better, then you're in the right place. This guide will walk you through everything you need to know if you want to get better sleep. I'll explain the science of sleep and how it works, discuss why many people suffer from sleep deprivation without knowing it, and offer practical tips for getting better sleep and having more energy.

Plain and simple, the purpose of this guide is to explain the science of how to sleep better. You can click the links below to jump to a particular section or simply scroll down to read everything. At the end of this page, you’ll find a complete list of all the articles I have written on sleep.

I. The Science of Sleep

Sleep is one of the strangest things we do each day. The average adult will spend 36 percent of his or her life asleep. For one-third of our time on earth, we transition from the vibrant, thoughtful, active organisms we are during the day and power down into a quiet state of hibernation.

But what is sleep, exactly? Why is it so important and so restorative for our bodies and minds? How does it impact our lives when we are awake?

The Purpose of Sleep

Sleep serves multiple purposes that are essential to your brain and body. Let's break down some of the most important ones.

The first purpose of sleep is restoration. Every day, your brain accumulates metabolic waste as it goes about its normal neural activities. While this is completely normal, too much accumulation of these waste products has been linked to neurological disorders such as Alzheimer's disease.

Alright, so how do we get rid of metabolic waste? Recent research has suggested that sleep plays a crucial role in cleaning out the brain each night. While these toxins can be flushed out during waking hours, researchers have found that clearance during sleep is as much as two-fold faster than during waking hours.

The way this process occurs is fairly remarkable:

During sleep, brain cells actually shrink by 60 percent, allowing the brain's waste-removal system—called the glymphatic system—to essentially “take out the trash” more easily. The result? Your brain is restored during sleep, and you wake up refreshed and with a clear mind.

The second purpose of sleep is memory consolidation. Sleep is crucial for memory consolidation, which is the process that maintains and strengthens your long-term memories. Insufficient or fragmented sleep can hamper your ability to form both concrete memories (facts and figures) and emotional memories.

Finally, sleep is paramount for metabolic health. Studies have shown that when you sleep 5.5 hours per night instead of 8.5 hours per night, a lower proportion of the energy you burn comes from fat, while more comes from carbohydrate and protein. This can predispose you to fat gain and muscle loss. Additionally, insufficient sleep or abnormal sleep cycles can lead to insulin insensitivity and metabolic syndrome, increasing your risk of diabetes and heart disease.

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

Deep sleep concept

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. "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. Note: Content may be edited for style and length.