power of sleep

7232019 Power of Sleep

httpslidepdfcomreaderfullpower-of-sleep 110



THE POWER

OF SLEEPNew research shows a good nightrsquosrest isnrsquot a luxurymdashitrsquos critical for your

brain and for your health

BY ALICE PARK

Photo-Illustration by Timothy Goodman for TIME

HEALTH



54

HEALTH | SLEEP

Which is why after long treating rest as a good-if-you-can-get-it obligation scientists are makingthe case that it matters much more than we thinkTheyrsquore not alone in sounding the alarm With upto 70 million of us not getting a good nightrsquos sleepon a regular basis the Centers for Disease Con-trol and Prevention considers insufficient sleep apublic-health epidemic In fact experts argue sleepis emerging as so potent a factor in better health thatwe need a societal shiftmdashand policies to supportitmdashto make sleep a nonnegotiable priority

THE CONSEQUE NCES OF SKIMPING

despite how great we feel after a nightrsquos

restmdashand putting aside what we now know aboutsleeprsquos importancemdashwe stubbornly refuse to swal-low our medicine pushing off bedtime and think-ing that feeling a little drowsy during the day isan annoying but harmless consequence Itrsquos notNearly 40 of adults have nodded off unintention-ally during the day in the past month and 5 havedone so while driving Insomnia or interruptedsleep nearly doubles the chances that workers willcall in sick And half of Americans say their un-

even sleep makes it harder to concentrate on tasksThose poor sleep habits are trickling down tothe next generation 45 of teens donrsquot sleep the rec-ommended nine hours on school nights leading25 of them to report falling asleep in class at leastonce a week according to a National Sleep Founda-tion survey Itrsquos a serious enough problem that theAmerican Academy of Pediatrics recently endorsedthe idea of starting middle and high schools later toallow for more adolescent shut-eye

Health experts have been concerned about oursleep-deprived ways for some time but the newinsights about the role sleep plays in our overallhealth have brought an urgency to the message

Sleep the experts are recognizing is the only timethe brain has to catch its breath If it doesnrsquot it maydrown in its own biological debrismdasheverythingfrom toxic free radicals produced by hard-workingfuel cells to spent molecules that have outlivedtheir usefulness

ldquoWe all want to push the system to get themost out of our lives and sleep gets in the wayrdquosays Dr Sigrid Veasey a leading sleep researcherand a professor of medicine at Perelman School ofMedicine at the University of Pennsylvania ldquoButwe need to know how far we can really push thatsystem and get away with itrdquo

Veasey is learning that brain cells that donrsquotget their needed break every night are like

when our heads hit the pillow every night

we tend to think wersquore surrendering Not just toexhaustion though there is that Wersquore also sur-

rendering our mind taking leave of our focus onsensory cues like noise and smell and blinkinglights Itrsquos as if wersquore powering ourselves down likewe do the electronics at our bedsidemdashgoing idle fora while only to spring back into action when thealarm blasts hours later

Thatrsquos what we think is happening But as sci-entists are now revealing that couldnrsquot be furtherfrom the truth

In fact when the lights go out our brains startworkingmdashbut in an altogether different way thanwhen wersquore awake At night a legion of neuronssprings into action and like any well-trained pla-

toon the cells work in perfect synchrony pulsingwith electrical signals that wash over the brainwith a soothing hypnotic flow Meanwhile dataprocessors sort through the reams of informationthat flooded the brain all day at a pace too over-whelming to handle in real time The brain alsoruns checks on itself to ensure that the exquisitebalance of hormones enzymes and proteins isnrsquottoo far off-kilter And all the while cleaners fol-low in close pursuit to sweep out the toxic detritusthat the brain doesnrsquot need and which can cause allkinds of problems if it builds up

This scientists are just now learning is thebrain on sleep Itrsquos naturersquos panacea more pow-

erful than any drug in its ability to restore andrejuvenate the human brain and body Gettingthe recommended seven to eight hours each nightcan improve concentration sharpen planningand memory skills and maintain the fat-burningsystems that regulate our weight If every one ofus slept as much as wersquore supposed to wersquod all belighter less prone to developing Type 2 diabetesand most likely better equipped to battle depres-sion and anxiety We might even lower our riskof Alzheimerrsquos disease osteoporosis and cancer

The trouble is sleep works only if we get enoughof it While plenty of pills can knock us out none so

far can replicate all of sleeprsquos benefits despite decadesrsquoworth of attempts in high-tech pharmaceutical labs

SLEEPDEPRIVATIONCOMES WITH

CONSEQUENCES THAT ARE

lsquoSCARY REALLYSCARYrsquo

mdashMary Carskadonprofessor of psychiatryand human behavior at

Brown University

P R E V I O U S

P A G E S G E T T Y

I MA G E S L E T T E R I N G T I M O T H Y

G

O O D MA N

F O R

T I ME I L L U S T R A T I O N S

B Y

B R O WN

B I R D

D E S I G N

F O R

T I ME



time September 22 2014 55

sleep If we chronically sleep-deprive ourselvesare we really aging our brainsrdquo she asks Ultimate-ly the research suggests itrsquos possible that a sleep-deprived brain belonging to a teen or a 20-year-oldwill start to look like that of a much older person

ldquoChronic sleep restriction is a stress on thebodyrdquo says Dr Peter Liu professor of medicine at

Harbor-UCLA Medical Center and LA Biomedi-cal Research Institute And the cause of that sleepdeprivation doesnrsquot always originate in familystrife financial concerns or job-related problemsThe way we live nowmdashchecking our phones everyminute hyperscheduling our days or our kidsrsquodays not taking time to relax without a screen infront of our facesmdashcontributes to a regular flow ofstress hormones like cortisol and all that artificiallight and screen time is disrupting our internalclocks Simply put our bodies donrsquot know whento go to sleep naturally anymore

This is why researchers hope their new

discoveries will change once and for all the waywe think aboutmdashand prioritizemdashthose 40 winks

overworked employees on consecutive doubleshiftsmdasheventually they collapse Working withmice she found that neurons that fire constantly tokeep the brain alert spew out toxic free radicals asa by-product of making energy During sleep theyproduce antioxidants that mop up these potentialpoisons But even after short periods of sleep loss

ldquothe cells are working hard but cannot make enoughantioxidants so they progressively build up free rad-icals and some of the neurons die offrdquo Once thosebrain cells are gone theyrsquore gone for good

After several weeks of restricted sleep saysVeasey the mice she studiedmdashwhose brains areconsidered a good proxy for human brains in labresearchmdashldquoare more likely to be sleepy when theyare supposed to be active and have more difficultyconsolidating [the benefits of] sleep during theirsleep periodrdquo

Itrsquos the same thing that happens in aging brainsshe says as nerve cells get less efficient at clearing

away their garbage ldquoThe real question is Whatare we doing to our brains if we donrsquot get enough

YOUR BODY

ON SLEEP

During the daythe body is more

focused on gettingthings done than

taking care of itselfThat changes whenwe sleep as moreenergy is devotedto repairing cells

churning out helpfulproteins and more

MUSCLES

Repairingmuscle tears orinjuries happens

during sleep

BONE

Wear and tearis remedied

with intensifiedbone building

PANCREAS

Without sleepwe become less

able to breakdown sugar from

our diet

BRAIN

The cells shrinksqueezing outdebris from a

busy day

SKIN

Beauty rest iswhen cells churn

out growth factorsto repair damage

and maintainelasticity



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HEALTH | SLEEP

sleeping brain is dramatic When the brain isawake it resembles a busy airport swelling withthe cumulative activity of individual messagestraveling from one neuron to another The activ-ity inflates the size of brain cells until they take up86 of the brainrsquos volume

When daylight wanes and we eventually fallasleep however those glial cells kick into actionslowing the brainrsquos electrical activity to abouta third of its peak frequency During those firststages of sleep called non-REM (rapid eye move-

ment) the firing becomes more synchronizedrather than haphazard The repetitive cycle lullsthe nerves into a state of quiet so in the next stageknown as REM the firing becomes almost non-existent The brain continues to toggle back andforth between non-REM and REM sleep through-out the night once every hour and a half

At the same time the sleeping brainrsquos cellsshrink making more room for the brain and spi-nal cordrsquos fluid to slosh back and forth betweenthem ldquoItrsquos like a dishwasher that keeps flushingthrough to wash the dirt awayrdquo says NedergaardThis cleansing also occurs in the brain when we

are awake but itrsquos reduced by about 15 since theglial cells have less fluid space to work with whenthe neurons expand

This means that when we donrsquot get enoughsleep the glial cells arenrsquot as efficient at clearingthe brainrsquos garbage That may push certain degen-erative brain disorders that are typical of later lifeto appear much earlier

Both Nedergaardrsquos and Veaseyrsquos work also hintat why older brains are more prone to developingAlzheimerrsquos which is caused by a buildup of amy-loid protein that isnrsquot cleared quickly enough

ldquoThere is much less flow to clear away thingsin the aging brainrdquo says Nedergaard ldquoThe garbage

system picks up every three weeks instead of everyweekrdquo And like any growing pile of trash the mo-lecular garbage starts to affect nearby healthy cellsinterfering with their ability to form and recallmemories or plan even the simplest tasks

The consequences of deprived sleep says DrMary Carskadon professor of psychiatry andhuman behavior at Brown University are ldquoscaryreally scaryrdquo

RIGHTSIZING YOUR SLEEP

all this isnrsquot actually so alarming since

therersquos a simple fix that can stop this nerve die-off

and slow the brainrsquos accelerated ride toward agingWhatrsquos needed says Carskadon is a rebranding of

GARBAGEMEN FOR YOUR BRAIN

ldquoi was nervous when i went to my first slee p

conferencerdquo says Dr Maiken Nedergaard thechatty and inquisitive co-director of the Center forTranslational Neuromedicine at the University ofRochester ldquoI was not trained in sleep and I cameto it from the outsiderdquo In fact as a busy motherand career woman she saw sleep the way most ofus probably do as a bother ldquoEvery single night Iwanted to accomplish more and enjoy time withmy family and I was annoyed to have to go to bedrdquo

Because shersquos a neuroscientist however Neder-gaard was inclined to ask a seemingly basic ques-tion Why do our brains need sleep at all Thereare two competing evolutionary theories One isthat sleeping organisms are immobile and there-fore less likely to be easy targets so perhaps sleepprovided some protection from prey The timeslumbering however took away from time spentfinding food and reproducing Another points outthat sleeping organisms are oblivious to creepingpredators making them ripe for attack Since boththeories seem to put us at a disadvantage Neder-gaard thought there had to be some other reason

the brain needs those hours offlineAll organs in the body use energy and in theprocess they spew out waste Most take care oftheir garbage with an efficient local system re-cruiting immune cells like macrophages to gobbleup the garbage and break it down or linking up tothe network of vessels that make up the lymphsystem the bodyrsquos drainage pipes

The brain is a tremendous consumer of en-ergy but itrsquos not blanketed in lymph vessels Sohow does it get rid of its trash ldquoIf the brain is notfunctioning optimally yoursquore dead evolutionarilyso there must be an advantage to exporting thegarbage to a less critical organ like the liver to take

care of itrdquo says NedergaardIndeed thatrsquos what her research shows She

found that an army of previously ignored cells inthe brain called glial cells turn into a massivepump when the body sleeps During the day gli-al cells are the unsung personal assistants of thebrain They cannot conduct electrical impulses likeother neurons but they support them as they sendsignals zipping along nerve networks to register asmell here and an emotion there For decades theywere dismissed by neuroscientists because theywerenrsquot the actual drivers of neural connections

But Nedergaard found in clinical trials on mice

that glial cells change as soon as organisms fallasleep The difference between the waking and

WHEN SHOULD

SCHOOL STARTThe American Academy ofPediatrics supports later

school start times forteens More than 1000

high schools have alreadydone this and their

students have shown im-provements in grades and

attentiveness in class



58 time September 22 2014

HEALTH | SLEEP

The ideal is to reset the bodyrsquos natural sleep-wake cycle a matter of training our bodies tosleep similar amounts every night and wake upat roughly the same time each day An even bet-ter way to rediscover our natural cycle is to get asmuch exposure to natural light as possible duringthe day while limiting how much indoor lightingincluding from computer and television screenswe see at night And of course the best way to ac-complish that is by making those seven to ninehours of sleep a mustmdashnot a luxury

ldquoI am now looking at and thinking of sleep asan lsquoenvironmental exposurersquordquo says Brown Univer-sityrsquos Carskadonmdashwhich means we should lookat sleep similarly to how we view air-pollutionexposure secondhand smoke or toxins in ourdrinking water If she and other researchers havetheir way checking up on sleep would be a rou-tine part of any physical exam and doctors wouldask about our sleep habits in the same way theyquery us about diet stress exercise our sex lifeour eyesightmdashyou name it And if we arenrsquot sleep-ing enough they might prescribe a change just asthey would for any other bad health habit

Some physicians are already taking the initia-tive but no prescription works unless we actuallytake it If our work schedule cuts into our sleeptime we need to make the sleep we get count byavoiding naps and exercising when we can dur-ing the day feeling tired will get us to fall asleepsooner If we need help dozing off gentle exercisesor yoga-type stretching can also help Creating asleep ritual can make sleep something we look for-ward to rather than something we feel obligatedto do so wersquore more likely to get our allotted timeinstead of skipping it A favorite book a warmbath or other ways to get drowsy might promptus to actually look forward to unwinding at the

end of the dayGiven what scientists are learning about how

much the bodymdashand especially the brainmdashneedsa solid and consistent amount of sleep in-the-knowdoctors arenrsquot waiting for more studies to provewhat we as a species know intuitively that cheat-ing ourselves of sleep is depriving us from takingadvantage of one of naturersquos most powerful drugs

ldquoWe now know that there is a lasting price topay for sleep lossrdquo says Veasey ldquoWe used to thinkthat if you donrsquot sleep enough you can sleep moreand yoursquoll be fine tomorrow We now know if youpush the system enough thatrsquos simply not truerdquo

mdashw it h re port ing by man dy oakl an der an dalexandra sifferlinnew york city 983150

sleep that strips away any hint of its being on thesidelines of our health

As it is sleep is so undervalued that getting by onfewer hours has become a badge of honor Plus welive in a culture that caters to the late-nighter from24-hour grocery stores to online shopping sites thatnever close Itrsquos no surprise then that more thanhalf of American adults donrsquot get the recommendedseven to nine hours of shut-eye every night

Whether or not we can catch up on sleepmdashonthe weekend saymdashis a hotly debated topic among

sleep researchers the latest evidence suggests thatwhile it isnrsquot ideal it might help When Liu theUCLA sleep researcher and professor of medicinebrought chronically sleep-restricted people intothe lab for a weekend of sleep during which theylogged about 10 hours per night they showedimprovements in the ability of insulin to processblood sugar That suggests that catch-up sleep mayundo some but not all of the damage that sleep de-privation causes which is encouraging given howmany adults donrsquot get the hours they need eachnight Still Liu isnrsquot ready to endorse the habit ofsleeping less and making up for it later ldquoItrsquos like

telling people you only need to eat healthy dur-ing the weekends but during the week you caneat whatever you likerdquo he says ldquoItrsquos not the righthealth messagerdquo

Sleeping pills while helpful for some are notnecessarily a silver bullet either ldquoA sleeping pill willtarget one area of the brain but therersquos never goingto be a perfect sleeping pill because you couldnrsquotreally replicate the different chemicals moving inand out of different parts of the brain to go throughthe different stages of sleeprdquo says Dr Nancy Collopdirector of the Emory University Sleep Center Stillfor the 4 of Americans who rely on prescriptionsleep aids the slumber they get with the help of a

pill is better than not sleeping at all or getting inter-rupted sleep At this point itrsquos not clear whether thebrain completes the same crucial housekeeping du-ties during medicated sleep as it does during naturalsleep and the long-term effects on the brain of rely-ing on sleeping pills arenrsquot known either

Making things trickier is the fact that we areunaware of the toll sleep deprivation takes on usStudies consistently show that people who sleepless than eight hours a night donrsquot perform as wellon concentration and memory tests but report feel-ing no deficits in their thinking skills That justperpetuates the tendency to dismiss sleep and its

critical role in everything from our mental facul-ties to our metabolic health

IS SCREEN

TIME

MESSING

WITH OUR

SLEEP

Any light at night in-cluding the glow fromphones tablets andlaptops can throwoff our body clocks

Our brains are fooledinto thinking itrsquos day

so sleep signalsdonrsquot get heard





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T h i s c o n t e n t i s f o r p e r s o n a l n o n - c o m m e r c i a l u s e a n d c a n o n l y b e s h a r e d w i t h o t h e r

a u t h o r i z e d u s e r s o f t h e E B S C O p r o d u c t s a n d d a t a b a s e s f o r t h e i r p e r s o n a l n o n - c o m m e r c i a l

u s e



THE POWER

OF SLEEPNew research shows a good nightrsquosrest isnrsquot a luxurymdashitrsquos critical for your

brain and for your health

BY ALICE PARK

Photo-Illustration by Timothy Goodman for TIME

HEALTH



54

HEALTH | SLEEP
























Brown University

P R E V I O U S

P A G E S G E T T Y


G

O O D MA N

F O R


B Y

B R O WN

B I R D

D E S I G N

F O R

T I ME














YOUR BODY

ON SLEEP





MUSCLES


during sleep

BONE



PANCREAS



our diet

BRAIN


busy day

SKIN














HEALTH | SLEEP

























WHEN SHOULD









HEALTH | SLEEP

















IS SCREEN

TIME

MESSING

WITH OUR

SLEEP








I5 OFFPROMOTION



WITH CODE

REAL15

ENDS OCTOBER 15


TM





u s e



54

HEALTH | SLEEP
























Brown University

P R E V I O U S

P A G E S G E T T Y


G

O O D MA N

F O R


B Y

B R O WN

B I R D

D E S I G N

F O R

T I ME














YOUR BODY

ON SLEEP





MUSCLES


during sleep

BONE



PANCREAS



our diet

BRAIN


busy day

SKIN














HEALTH | SLEEP

























WHEN SHOULD









HEALTH | SLEEP

















IS SCREEN

TIME

MESSING

WITH OUR

SLEEP








I5 OFFPROMOTION



WITH CODE

REAL15

ENDS OCTOBER 15


TM





u s e














YOUR BODY

ON SLEEP





MUSCLES


during sleep

BONE



PANCREAS



our diet

BRAIN


busy day

SKIN














HEALTH | SLEEP

























WHEN SHOULD









HEALTH | SLEEP

















IS SCREEN

TIME

MESSING

WITH OUR

SLEEP








I5 OFFPROMOTION



WITH CODE

REAL15

ENDS OCTOBER 15


TM





u s e











HEALTH | SLEEP

























WHEN SHOULD









HEALTH | SLEEP

















IS SCREEN

TIME

MESSING

WITH OUR

SLEEP








I5 OFFPROMOTION



WITH CODE

REAL15

ENDS OCTOBER 15


TM





u s e




HEALTH | SLEEP

















IS SCREEN

TIME

MESSING

WITH OUR

SLEEP








I5 OFFPROMOTION



WITH CODE

REAL15

ENDS OCTOBER 15


TM





u s e





I5 OFFPROMOTION



WITH CODE

REAL15

ENDS OCTOBER 15


TM





u s e





u s e

power of sleep

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