The Black-White Sleep Gap

An unexpected challenge in the quest for racial justice.

This illustration can only be used with the Brian Resnick story that originally ran in the 10/233/2015 issue of National Journal magazine. 

In 2005, re­search­ers at the Uni­versity of Cali­for­nia, San Diego, began an ex­per­i­ment that would last five years. One by one, they brought 164 study par­ti­cipants to a sleep lab at the U.C. San Diego Med­ic­al Cen­ter, a room with a sweep­ing view of the city and the sur­round­ing val­ley. There, par­ti­cipants un­der­went poly­so­m­no­graphy, the most com­pre­hens­ive sleep test known to sci­ence. A poly­so­m­no­graphy ma­chine is an oc­topus of a med­ic­al device: It has scalp sensors to re­cord brain-wave pat­terns; eye track­ers to as­sess rap­id eye move­ments; breath­ing sensors that are placed on the nose, mouth, and around the chest; a blood-oxy­gen sensor for the fin­gers; and sensors on the legs to track move­ment. The ma­chine pro­duces a chart—re­sem­bling a cross between a mu­sic­al com­pos­i­tion and a seis­mo­gram—that traces the brain and body minute by minute through the night.

“I think it’s quite beau­ti­ful per­son­ally,” says Li­anne Tom­fohr, who was the lead au­thor on the study and is now a psy­cho­logy pro­fess­or at the Uni­versity of Cal­gary. “We can put [sensors] on their head and, through the elec­tri­city in their brains, see how deeply they are sleep­ing. It’s a little bit mys­tic­al to me that it is even pos­sible.”

The San Diego re­search­ers planned to use the poly­so­m­no­graphy ma­chine to doc­u­ment slow-wave sleep—the phase of sleep “when it’s really hard to wake you up,” as Tom­fohr de­scribes it. Slow-wave sleep is thought to be the most res­tor­at­ive peri­od of sleep, and it’s im­port­ant to good health: Ex­per­i­ments where people are denied slow-wave sleep on pur­pose have shown that bod­ies quickly change for the worse. (One pa­per, pub­lished in the Pro­ceed­ings of the Na­tion­al Academy of Sci­ences in 2007, found that study par­ti­cipants who were denied slow-wave sleep for three nights—re­search­ers would sound an alarm in their ears when they entered this sleep phase—be­came less sens­it­ive to in­sulin, a pre­curs­or to dia­betes.)

But it wasn’t just slow-wave sleep in gen­er­al that in­ter­ested the re­search­ers; they spe­cific­ally hoped to com­pare how blacks and whites ex­per­i­enced slow-wave sleep. And what they found was dis­turb­ing. Gen­er­ally, people are thought to spend 20 per­cent of their night in slow-wave sleep, and the study’s white par­ti­cipants hit this mark. Black par­ti­cipants, however, spent only about 15 per­cent of the night in slow-wave sleep.

The study was just one data point in a mount­ing pile of evid­ence that black Amer­ic­ans aren’t sleep­ing as well as whites. This past June, the journ­al Sleep pub­lished a study on the sleep qual­ity of black, white, Chinese, and His­pan­ic adults in six cit­ies across the United States. The par­ti­cipants were pooled from the Multi-Eth­nic Study of Ath­er­o­scler­o­sis (MESA), a co­hort of more than 6,000 people who, for the last 15 years, have been in­ter­mit­tently pricked, prod­ded, and as­sessed to dis­cov­er how geo­graphy and race in­flu­ence health over time. (More than 950 pa­pers have been pub­lished on this co­hort. It’s from them that re­search­ers have found evid­ence that the farther people live from a wealth­i­er area, the more likely they are to de­vel­op in­sulin res­ist­ance—or that blacks ap­pear to have high­er levels of the sub­stances that cause blood to clot.)

For a week, par­ti­cipants in the MESA study wore acti­graphy bands, Fit­bit-like brace­lets that can es­tim­ate the amount of time a per­son is asleep. In a sep­ar­ate test, they un­der­went poly­so­m­no­graphy. The res­ults? “The in­suf­fi­cient amount of sleep, the short sleep dur­a­tion of the Afric­an-Amer­ic­ans really stood out,” says Susan Red­line, a Har­vard pro­fess­or of sleep medi­cine and one of the study’s co-au­thors. “It really em­phas­ized that Afric­an-Amer­ic­ans, as a group, are get­ting the least amount of sleep com­pared, at least, to the three oth­er groups.” Whites in the study slept an av­er­age of 6.85 hours; blacks slept an av­er­age of 6.05 hours.

Com­pared with white par­ti­cipants in the study, black par­ti­cipants—most epi­demi­olo­gists prefer “black” to Afric­an-Amer­ic­an; it en­com­passes more people—were five times more likely to get short sleep, defined as less than six hours a night. (His­pan­ic par­ti­cipants were 1.8 times more likely to get short sleep; Chinese par­ti­cipants were 2.3 times more likely.) Blacks were also more likely to re­port feel­ing sleepy in the day­time, and they woke up more of­ten in the middle of the night. “Not­ably,” the study reads, “these as­so­ci­ations re­mained evid­ent after ad­just­ment for sex, age, study site, and [body mass in­dex].”

Fif­teen years ago, the in­ter­sec­tion of sleep and race wasn’t stud­ied much at all. Re­search­ers in the sleep field “hadn’t really thought about this idea—by race, by eco­nom­ic status—that people had dif­fer­ent amounts of sleep,” says Di­ane Laud­er­dale, an epi­demi­olo­gist at the Uni­versity of Chica­go. In the early 2000s, Laud­er­dale was part of an ef­fort that was one of the first to find ra­cial dif­fer­ences in sleep us­ing ob­ject­ive meas­ure­ments, as op­posed to self-re­ports. Study­ing a 669-per­son co­hort in Chica­go—44 per­cent were black; the rest were white—she and her col­leagues found, on av­er­age, an hour dif­fer­ence between blacks’ and whites’ sleep.

What’s more, the sleep dis­crep­ancy per­sisted even when the re­search­ers tried to con­trol for eco­nom­ic factors: As blacks got wealth­i­er, the gap in sleep nar­rowed, but did not go away en­tirely. “The race gap is de­creased if you take in­to ac­count some in­dic­at­or of eco­nom­ics,” says Laud­er­dale, “but it’s not elim­in­ated in the data that I have looked at.” In­deed, in the San Diego study, re­search­ers also con­cluded that there were ra­cial dif­fer­ences in sleep re­gard­less of in­come. (It should be noted, however, that re­search­ers con­cede their at­tempts to con­trol for eco­nom­ic in­dic­at­ors are far from per­fect. “We know our meas­ures for ad­just­ing for so­cioeco­nom­ic status are still some­what lim­ited,” says Red­line. “Some­times the vari­ation isn’t great enough.”)

So what ex­plains the gap? It’s an in­triguing and still some­what open-ended sci­entif­ic mys­tery. (And one that is that gradu­ally get­ting more and more at­ten­tion: In Ju­ly, the ra­dio pro­gram Freako­nom­ics ded­ic­ated a seg­ment to doc­u­ment­ing the dis­crep­ancy and try­ing to ex­plain why it might ex­ist.) But the black-white sleep gap isn’t just a ques­tion for sci­ence; it also has im­plic­a­tions for the policy world. Sleep, after all, may be a key factor in a tra­gic spir­al: It ap­pears to be both a symp­tom of health prob­lems that dis­pro­por­tion­ately af­fect black com­munit­ies and also a cause of those same prob­lems. Which is why it seems worth ask­ing: Are there policy in­ter­ven­tions that could, real­ist­ic­ally, help to im­prove how black Amer­ic­ans sleep?

FOR MOST OF hu­man his­tory, the ques­tion “why do we sleep” has been an ab­so­lute un­known. Be­fore Wil­li­am C. De­ment con­duc­ted the first overnight sleep re­cord­ings of brain activ­ity in the early 1950s, our know­ledge of sleep was “pre­his­tor­ic,” he wrote in a 1998 es­say, “The Study of Hu­man Sleep: A His­tor­ic­al Per­spect­ive.” Pri­or to that point, the pre­vail­ing the­ory was that sleep was simply when the brain went dormant, re­cov­er­ing its en­ergy to be­gin a new day. Sig­mund Freud him­self dis­missed sleep’s sig­ni­fic­ance. “I have had little oc­ca­sion to con­cern my­self with the prob­lem of sleep, as this is es­sen­tially a physiolo­gic­al prob­lem,” he wrote. To him, sleep was sub­ser­vi­ent to dreams, which were the mind’s way of chan­nel­ing away anxi­et­ies and per­ver­sions.

In 1953, the dis­cov­ery of REM (rap­id eye move­ment) sleep set off a rush of re­search in­to what was hap­pen­ing in­side the brain at night. Sci­ent­ists found the sleep­ing mind wasn’t dormant at all, but en­gaged in a flurry of struc­tured activ­ity. We pro­gress through the night in a cho­reo­graphed or­der: from light sleep, to deep sleep, to REM, and then back again. We dream in REM—the most act­ive phase of sleep—but the brain is busy throughout the night. In the quieter stages, the brain is still 80 per­cent ac­tiv­ated, “and thus cap­able of ro­bust and elab­or­ate in­form­a­tion-pro­cessing,” a 2005 art­icle in the journ­al Nature ex­plains. Sleep is when the brain re­or­gan­izes it­self and con­sol­id­ates memor­ies; it’s es­sen­tial for learn­ing and con­cen­tra­tion. (Mul­tiple stud­ies have, for in­stance, found that after day­light sav­ings time be­gins in the spring—a day when people are likely to have their sleep dis­rup­ted—the num­ber of traffic fatal­it­ies in­creases.)

While sleep is cru­cial for day-to-day func­tion­ing, it’s also cru­cial for health. As psy­cho­lo­gists were dis­cov­er­ing the ar­chi­tec­ture of sleep, epi­demi­olo­gists were be­gin­ning to as­sess its im­pact on our bod­ies. “In the 1960s, there were a num­ber of large com­munity-based stud­ies that sought to fig­ure out what the real causes of death were in the com­munity,” says Mi­chael Grand­ner, dir­ect­or of sleep and health re­search at the Uni­versity of Ari­zona. Large-scale epi­demi­olo­gic­al pro­jects like the Fram­ing­ham heart study (be­gun in 1948) and the Alameda County study (be­gun in 1965) helped to cre­ate the max­ims that dom­in­ate pub­lic health to this day—smoking kills, diet and ex­er­cise factor in­to heart dis­ease, al­co­hol is dan­ger­ous—but hid­den in all that data was an­oth­er find­ing: In meta-ana­lyses of these large-scale stud­ies, “you get this u-shape for mor­tal­ity,” Grand­ner says. Both too much sleep (longer than eight hours) and too little sleep (short­er than six hours) put people at high­er odds for early death. (Ac­cord­ing to Grand­ner, there’s a clear­er con­sensus around the idea that too little sleep is bad for health; the ef­fects of too much sleep re­main an open and de­bated ques­tion.)

In 2002, Grand­ner’s ment­or, Daniel Krip­ke, a psy­chi­at­rist at the Uni­versity of Cali­for­nia, San Diego, pub­lished a re­port com­pil­ing data from more than 1 mil­lion men and wo­men aged 30 to 102. “The best sur­viv­al was found among those who slept sev­en hours per night,” the study found. Says Grand­ner: “This was, and still is, the largest study ever on this top­ic and ar­gu­ably the most clear.”

To un­der­stand why sci­ent­ists hy­po­thes­ize that poor sleep causes poor health, we need to dive in­to the smal­lest com­pon­ents of the hu­man body. It is here sci­ent­ists have made the biggest leaps in con­nect­ing sleep with over­all health. Over the last two dec­ades, there has been a shift in the way sci­ent­ists un­der­stand sleep, ex­plains Al­lan Pack, who re­searches sleep and ge­n­om­ics at the Uni­versity of Pennsylvania’s Perel­man School of Medi­cine. “The idea was you go to sleep, the brain shuts down, something hap­pens that’s help­ful to” your brain, Pack says. Now, however, “one of the things we know is there’s not only a clock in your brain con­trolling the sleep-wake pat­tern, there are clocks in every tis­sue, es­sen­tially.”

Sci­ent­ists have dis­covered “clock genes,” tiny bits of DNA that act like a bio­lo­gic­al met­ro­nome: By reg­u­larly flip­ping on and off, they help the body main­tain its sense of time. And not only are these clocks in every tis­sue in every hu­man, or in every tis­sue in every mam­mal, but they can be found in “vir­tu­ally every or­gan­ism on the sur­face of the plan­et,” says Mi­chael Twery, dir­ect­or of the Na­tion­al In­sti­tutes of Health’s Na­tion­al Cen­ter on Sleep Dis­orders Re­search. Cycles in activ­ity and rest are fun­da­ment­al in the ar­chi­tec­ture of life.

Mess­ing with these cycles—es­sen­tially throw­ing the body’s met­ro­nome off beat—throws the whole body off beat. “When you have situ­ations like the mis­tim­ing of sleep, or not enough sleep, you can con­ceiv­ably al­ter clock [gene] func­tion and then al­ter the ex­pres­sion of all these im­port­ant genes that are reg­u­lat­ing things like meta­bol­ism, or skelet­al muscle func­tion, pan­cre­at­ic func­tion,” says John Ho­gen­esch, a chro­n­o­bi­o­lo­gist at the Uni­versity of Pennsylvania who stud­ies clock genes in mam­mals. Like tox­ins in the food chain, the ef­fects ac­cu­mu­late up­ward from there: Cells that have their clock genes dis­rup­ted don’t pro­duce the right pro­teins, those pro­teins then don’t reg­u­late tis­sues well, and or­gan sys­tems show strain.

“I have never seen a study that hasn’t shown a direct association between neighborhood quality and sleep quality,” one expert says.

In the late 1990s, an in­ven­tion called the mi­croar­ray—a com­puter chip that al­lows re­search­ers to study how many genes are turned on in a giv­en cell—burst open this re­search. Now, sci­ent­ists could watch, in near-real time, what was hap­pen­ing to cells in an­im­als that had been denied sleep. They didn’t look healthy. “When you keep an­im­als awake, you get this phe­nomen­on called the un­fol­ded pro­tein re­sponse,” Pack ex­plains. Pro­teins are the build­ing blocks of the cell. If the pro­teins are poorly con­struc­ted, or, in sci­ence speak, un­fol­ded—like a Lego block with a mis­shapen con­nect­or—they won’t work. “Then you either have got to des­troy them or what hap­pens is they ag­greg­ate in­to lumps,” Pack says. “And you get these pro­tein ag­greg­ates, which are very tox­ic to the cell.”

How those dis­rup­tions in the cell come to af­fect en­tire or­gan sys­tems isn’t en­tirely un­der­stood. But evid­ence from mo­lecu­lar bio­logy, epi­demi­ology, and psy­cho­logy points to the idea that poor sleep is a risk factor for heart dis­ease, dia­betes, and obesity—which are all ail­ments that dis­pro­por­tion­ately af­fect black com­munit­ies. In Amer­ica, blacks are 33 per­cent more likely to die from heart dis­ease than the pop­u­la­tion at large, 1.7 times more likely to have dia­betes, and 1.5 times more likely to be obese. For every 100,000 blacks, it’s es­tim­ated that heart dis­ease takes away 1,691.1 years of po­ten­tial life in a giv­en year. For whites, that fig­ure is 900.9 years.

Over­all, if we factor out deaths caused by aging, the mor­tal­ity rate for black men—from all causes—in the United States is 1,104 per 100,000, ac­cord­ing to the Cen­ters for Dis­ease Con­trol and Pre­ven­tion. For white men, the mor­tal­ity rate is 878.5 deaths per 100,000. For white wo­men, that fig­ure is 630.8 per 100,000; for black wo­men, it’s 752.5. Could sleep ex­plain part of the dif­fer­ence between blacks and whites?

The best sci­ent­ists are al­ways skep­tic­al, and the sleep re­search­ers I spoke to were no ex­cep­tion. “It’s plaus­ible to sug­gest ra­cial dif­fer­ences in sleep, whatever the cause, might po­ten­tially be one, maybe a small piece,” Grand­ner says. “It’s prob­ably not ex­plain­ing the whole thing or a large frac­tion of it, but could be play­ing a role in some of these health dis­par­it­ies.”

One thing, however, is cer­tain: Sleep dis­par­it­ies do ex­ist. “I think we can say there’s a great deal of evid­ence that there are race dif­fer­ences,” Laud­er­dale says. And giv­en the link between sleep and well-be­ing, it seems clear that those dif­fer­ences are worth tak­ing ser­i­ously as a mat­ter of pub­lic health.

ON THE QUES­TION of how to ex­plain the black-white sleep gap it­self, re­search­ers have a num­ber of re­lated the­or­ies. (There is a con­sensus that in­nate bio­lo­gic­al dif­fer­ences between blacks and whites are not a factor.) The stress caused by dis­crim­in­a­tion is one strong pos­sib­il­ity. In the San Diego sleep study, Tom­fohr’s team knew, go­ing in, that slow-wave sleep is very sens­it­ive to stress—which is, in turn, our body’s sig­nal to re­main vi­gil­ant against per­ceived threats, in­clud­ing dis­crim­in­a­tion. “That was our thought: If people are feel­ing really dis­crim­in­ated against, then of course they are not go­ing to want to get in­to a really deep stage of sleep,” she says.

After the par­ti­cipants’ stays in the San Diego lab, re­search­ers had them take a sur­vey, de­signed to as­sess the level of dis­crim­in­a­tion they felt on any giv­en day. (Par­ti­cipants were asked to agree or dis­agree with state­ments, in­clud­ing “In my life, I have ex­per­i­enced pre­ju­dice be­cause of my eth­ni­city” and “My eth­nic group is of­ten cri­ti­cized in this coun­try.”) Armed with this in­form­a­tion, Tom­fohr and her col­leagues could then de­term­ine a cor­rel­a­tion between dis­crim­in­a­tion and sleep. And it turned out that there was, in fact, a cor­rel­a­tion: More dis­crim­in­a­tion meant less slow-wave sleep. “If you can take out that dis­crim­in­a­tion piece, the av­er­age Afric­an-Amer­ic­an and the av­er­age Caucasi­an look at lot more sim­il­ar,” she says. “It’s not per­fect, but in terms of sleep, a lot of the dis­par­ity goes away.”

Dani­elle L. Beatty Moody, a psy­cho­lo­gist at the Uni­versity of Mary­land, Bal­timore County, con­duc­ted a sim­il­ar test while work­ing as a post-doc­tor­al schol­ar in the psy­chi­atry de­part­ment of the Uni­versity of Pitt­s­burgh in the late 2000s. People who are dis­crim­in­ated against, she be­lieves, carry worry throughout the day. And that worry lit­er­ally keeps them up at night. “It’s un­com­fort­able for them to sleep be­cause they are think­ing back over mis­treat­ment, think­ing back over mal­treat­ment, think­ing back over bi­as they ex­per­i­enced,” she says. “In think­ing about those ex­per­i­ences, they are get­ting more aroused, more cog­nit­ive arous­al, which does the op­pos­ite of what you need it to do to go to sleep.”

Lauren Hale, a pro­fess­or of pre­vent­ive medi­cine at Stony Brook Uni­versity and the found­ing ed­it­or-in-chief of the journ­al Sleep Health, makes a sim­il­ar but slightly dif­fer­ent point: She ar­gues that sleep is a re­flec­tion of a per­son’s agency. The more con­trol you have over your life—the more free­dom you have fin­an­cially, the more free­dom you have to live where you choose, the more con­trol you have over what you eat and when you eat it, the more you have the lux­ury of pos­sess­ing the time and equip­ment to ex­er­cise—the more likely you are able to cre­ate an en­vir­on­ment that fosters good sleep. “[S]kep­tics can­not ar­gue that people with poor sleep habits simply ‘choose’ to sleep poorly,” Hale and a co-au­thor wrote in 2010. “Sleep should be viewed as a con­sequence of something oth­er than choice.”

Neigh­bor­hoods also ap­pear to mat­ter when it comes to sleep health. “I have nev­er seen a study that hasn’t shown a dir­ect as­so­ci­ation between neigh­bor­hood qual­ity and sleep qual­ity,” Hale tells me. “Those two are linked.” And black fam­il­ies are more likely to live in poorer neigh­bor­hoods, even if they are middle-in­come. (“Even among white and black fam­il­ies with sim­il­ar in­comes, white fam­il­ies are much more likely to live in good neigh­bor­hoods—with high-qual­ity schools, day-care op­tions, parks, play­grounds and trans­port­a­tion op­tions,” wrote Dav­id Leon­hardt re­cently in The New York Times, sum­mar­iz­ing the res­ults of a Stan­ford study by Pro­fess­or Sean Rear­don.)

Feel­ings of safety are key here. Hale the­or­izes that—as with dis­crim­in­a­tion—noisy, un­safe, dis­orderly neigh­bor­hoods in­crease stress and the need for vi­gil­ance. “If you know some­body in your neigh­bor­hood who has had a break-in, you might feel pretty un­com­fort­able shut­ting your eyes fall­ing asleep while your two or three chil­dren are sleep­ing in the room next door and no one else is there to pro­tect them,” she says. “And that type of in­sec­ur­ity, wheth­er it’s fin­an­cial or phys­ic­al safety, is more com­mon among people who don’t have con­trol over their en­vir­on­ment, be­cause if you did have con­trol over your en­vir­on­ment, you’d say, ‘I’m get­ting out of here.’ ”

Hale has been in­volved in sev­er­al stud­ies that com­pare levels of dis­order in a neigh­bor­hood—as meas­ured by clean­li­ness, crime, pres­ence of graf­fiti, and so on—with sleep and health. Over­all, she finds, poor sleep can ex­plain 20 per­cent of the dif­fer­ence between the good health found in rich neigh­bor­hoods and the bad health found in poor ones. “Based on these res­ults, tar­geted in­ter­ven­tions de­signed to pro­mote sleep qual­ity in dis­ad­vant­aged neigh­bor­hoods (e.g., com­munity-based sleep pro­mo­tion and noise level or­din­ances) could help to im­prove the phys­ic­al health of res­id­ents in the short-term,” Hale writes in one of her co-au­thored pa­pers in the journ­al Pre­vent­ive Medi­cine. And while “com­munity-based sleep pro­mo­tion” may sound like an im­possibly vague in­ter­ven­tion, there are, in fact, pro­grams un­der­way that show how it might be done.

SOME OF THE more prac­tic­al re­search aimed at help­ing black Amer­ic­ans to sleep bet­ter is be­ing con­duc­ted by Gir­ardin Jean-Louis, a cha­ris­mat­ic Haitian-born psy­cho­lo­gist who runs a lab ded­ic­ated to sleep and health dis­par­it­ies at New York Uni­versity’s Cen­ter for Health­ful Be­ha­vi­or Change. When I first star­ted re­port­ing on this top­ic, Jean-Louis’s name was brought up in just about every con­ver­sa­tion. “What I think is in­nov­at­ive about what Dr. Jean-Louis is do­ing is that he goes in­to the com­munity and finds out from the stake­hold­ers what we need to do and works with them,” says Kristen Knut­son, a bio­med­ic­al an­thro­po­lo­gist at the Uni­versity of Chica­go who has been study­ing the link between sleep and health out­comes.

It’s 84 de­grees and rising on a Sat­urday in Au­gust when I go to see Jean-Louis’s work in ac­tion. In the St. Al­bans com­munity of Ja­maica, Queens, Azizi Seixas—a mem­ber of Jean-Louis’s team—takes the stage out­side Christ Church In­ter­na­tion­al. Con­greg­ants and com­munity mem­bers sit un­der tents in the closed-off street ad­ja­cent to the church, which, des­pite its cor­al-pink bricks, is as non­des­cript and in­dus­tri­al as the self-stor­age fa­cil­ity next door.

Today is the church’s an­nu­al health fair. Six tents line the street. At one, pass­ersby can get their blood pres­sure or blood-sug­ar levels taken (though I don’t see any who do). An­oth­er sta­tion is giv­ing away free re­flex­o­logy foot mas­sages (much more pop­u­lar).

Seixas is here to re­cruit par­ti­cipants for a year­long study that Jean-Louis’s lab is con­duct­ing. St. Al­bans—a work­ing- to middle-class com­munity that is al­most en­tirely black—isn’t the poorest neigh­bor­hood in the city, but it suf­fers from the same stressors as many oth­er minor­ity areas: people work­ing mul­tiple jobs at odd hours; people strug­gling to pay for mort­gages while tak­ing care of their fam­il­ies. “People have two or three jobs—they don’t get enough sleep,” the nurse man­ning the blood-pres­sure sta­tion tells me. “You come in [from one job], you get five or six minutes sleep—or maybe two hours of sleep—then you have to go out to an­oth­er job. They don’t real­ize. They just think, ‘Oh, I’m tired.’ They don’t real­ize they’re de­vel­op­ing a prob­lem that’s great­er than be­ing just tired.”

Thirty per­cent of adult res­id­ents in the great­er Ja­maica area are obese. The death rate from dia­betes in Ja­maica is high­er than in both Queens and New York City as a whole. Ja­maica also has one of the highest rates of heart-at­tack hos­pit­al­iz­a­tions in the city. “When you don’t sleep well, guess what hap­pens?” Seixas asks the crowd from the stage. “Over time, that builds up, and it builds up, and it builds up, and what we have found is that many of the times, the hy­per­ten­sion—the high blood pres­sure—the dia­betes, all those health con­di­tions are as­so­ci­ated. They have something to do with sleep.”

As with sleep prob­lems more generally, there is a ra­cial dis­par­ity when it comes to sleep apnea.

Seixas dir­ects those as­sembled to a sta­tion that NYU has set up for free sleep screen­ings. They’ll ask for his­tory of snor­ing, in­som­nia, and day­time sleep­i­ness. Their spe­cif­ic tar­get is to identi­fy people at risk for ob­struct­ive sleep apnea, a po­ten­tially deadly dis­order where a per­son in­ter­mit­tently stops breath­ing dur­ing sleep. These ces­sa­tions, called apneas, can oc­cur hun­dreds of times in a night, and each gen­er­ally lasts 10 to 30 seconds.

People with sleep apnea get truly aw­ful sleep. Es­sen­tially, it’s a con­di­tion that max­im­izes all of the health prob­lems re­lated to short sleep dur­a­tion. Like short sleep­ers, people with sleep apnea are at high­er risk for high blood pres­sure, dia­betes, and weight gain. “We take some of these people with hy­per­ten­sion, and we give them an­ti­hyper­tens­ive med­ic­a­tions. Of­ten times, what we find is there is a sub­set of people, primar­ily blacks, where they don’t re­spond to the hy­per­tens­ive med­ic­a­tion,” Seixas tells me. “What we found in our stud­ies is that a lot of these people have un­detec­ted, un­treated sleep dis­orders, par­tic­u­larly sleep apnea.”

As with sleep prob­lems more gen­er­ally, there is a ra­cial dis­par­ity when it comes to sleep apnea. “Not only does it seem like they’re more likely to have the dis­order, they’re less likely to make it to a doc­tor to have treat­ment pre­scribed, and even if they get treat­ment pre­scribed, they’re less ad­her­ent and don’t use it as much,” Knut­son says. “So, all across, from step A to step Z of get­ting treated, there are dis­par­it­ies.” In the June Sleep re­port, 12.8 per­cent of blacks in the co­hort had sleep apnea; 7.4 per­cent of whites did. An over­view pa­per in the 2015 An­nu­al Re­view of Pub­lic Health cites 14 per­cent of blacks as hav­ing the con­di­tion—the fig­ures for whites are around half that—and also states that sleep apnea is four to six times as pre­val­ent in black chil­dren. (It’s hard to say how pre­val­ent sleep apnea is—among blacks, whites, or in the over­all pop­u­la­tion—be­cause apneas are usu­ally so short that people don’t re­mem­ber wak­ing up from them.)

Apnea is just one as­pect of Jean-Louis’s work on sleep. One unit of his lab is look­ing in­to the noise levels of dif­fer­ent New York neigh­bor­hoods and then de­term­in­ing their im­pacts on sleep and blood pres­sure. In an­oth­er pro­gram, the lab is re­strict­ing one hour of sleep in a group of adults for 12 weeks to see how the change af­fects their bod­ies. They also have an NIH-fun­ded pro­gram design­ing a web­site for sleep-health edu­ca­tion. When I vis­it their of­fices a few days after the health fair, the team—a di­verse col­lec­tion of aca­dem­ics in their 20s and 30s—is de­bat­ing wheth­er a stock im­age of a black man sleep­ing next to a bowl of food is ap­pro­pri­ate for the edu­ca­tion web­site.

Un­til 2000, Jean-Louis was fo­cused on lab-based work at the Uni­versity of Cali­for­nia, San Diego, re­search­ing un­der Daniel Krip­ke. But he found that the con­trolled, sterile en­vir­on­ment wasn’t sat­is­fy­ing. “You have got to be in the com­munity where you are ac­tu­ally touch­ing people’s lives,” he says. “To me, this is more re­ward­ing.”

While Jean-Louis was in San Diego, evid­ence was mount­ing that not only were blacks not get­ting good sleep but they were more at risk for sleep dis­orders. San Diego is only about 5 per­cent black—a fig­ure not con­du­cive to re­search on race—so Jean-Louis took a po­s­i­tion at SUNY Down­state Col­lege of Medi­cine in Brook­lyn, a place where he just had to step out­side to be im­mersed in the black com­munity. He and his child­hood friend and fre­quent col­lab­or­at­or Ferdin­and Zizi—a sleep-health re­search­er as well—would go to churches, barber shops, beauty salons, and com­munity cen­ters to re­cruit people for fo­cus groups and find out what was hold­ing their sleep health back.

What they found was a com­munity un­fa­mil­i­ar with sleep health and hes­it­ant to un­der­go lab tests. One of their stud­ies tracked 421 black pa­tients who were re­ferred to get tested for sleep apnea. Just 38 per­cent showed up to get a dia­gnos­is (even though all were called by the doc­tor to re­mind them of their ap­point­ments). Of those 38 per­cent, nearly all re­ceived a pos­it­ive dia­gnos­is. Many of those re­ferred for sleep tests were obese, hy­per­tens­ive, and had high cho­les­ter­ol. Miss­ing out on sleep treat­ments meant they were miss­ing out on an op­por­tun­ity to man­age those con­di­tions as well.

Jean-Louis joined NYU in 2013. In his cur­rent study—which is be­ing fun­ded by the NIH at a cost of $423,750—he and his col­leagues are try­ing to fig­ure out wheth­er simple in­ter­ven­tions could bet­ter dia­gnose and treat minor­it­ies for sleep apnea. (For the first year, the study was only for blacks; now it has been opened up to all minor­it­ies.) Hence the team’s vis­it to places like Christ Church In­ter­na­tion­al. “Gir­ardin’s stud­ies are pi­on­eer­ing,” says Twery of the NIH, “in the sense he is do­ing com­munity-based re­search to un­der­stand the cul­tur­al basis of the prob­lem and how to im­prove the health of these com­munit­ies.”

At the health fair, if com­munity mem­bers are iden­ti­fied as be­ing at risk for sleep apnea, they’re in­vited to join the study. Once in the study, they are first as­signed a peer health edu­cat­or. This per­son, who usu­ally lives in the same com­munity, guides the par­ti­cipants through the pro­cess of get­ting a dia­gnos­is and then helps them ad­here to treat­ments.

“People like stor­ies. They like you to en­gage them,” Jean-Louis says. “So you might find the first five to ten minutes, you’re just talk­ing about their lives.” He be­lieves this is the key as­pect of the in­ter­ven­tion. The idea is to be sens­it­ive to any war­i­ness pa­tients may have of med­ic­al in­sti­tu­tions and not to blame them for lack­ing know­ledge. In his pa­pers, he calls this ap­proach cul­tur­ally tailored edu­ca­tion. “When people feel you value them, you value their time, they’ll do it. But you just can’t show up with a clip­board and ask­ing ques­tions,” he ex­plains.

The health edu­cat­ors—who have six weeks of train­ing—re­main in con­tact with the par­ti­cipants for a year, act­ing as health coaches and guid­ing them to­ward treat­ment goals. “Un­til people are able to un­der­stand what sleep apnea is about, they’re go­ing to be res­ist­ant,” Lys­tra Harry, one of the edu­cat­ors, tells me. “Whatever de­cision they choose to make, we re­spect it.” Not every­one will get a dia­gnos­is, but every­one will be edu­cated in sleep health, which could help al­le­vi­ate prob­lems of short sleep as well.

Jean-Louis says he has pre­lim­in­ary data that shows this ap­proach is work­ing. People who re­ceive cul­tur­ally tailored sleep edu­ca­tion are, he says, four times more likely to make an ap­point­ment for a fol­low-up ex­am. “And once they are in, they will ac­tu­ally stay in,” he says.

For pri­vacy reas­ons, the NYU team wouldn’t put me in touch with any par­ti­cipants in the study. But the lead peer health edu­cat­or in­tro­duced me to her sis­ter, Kim­berly Turn­er, a 55-year-old Afric­an-Amer­ic­an res­id­ent of Ca­nar­sie, Brook­lyn, who had been dia­gnosed with sleep apnea. Be­fore she was dia­gnosed, she told me, she felt like she was in the Twi­light Zone. Time seemed to dis­ap­pear. A cowork­er sit­ting next to her would sud­denly van­ish. She’d stop at a red light and then, an in­stant later, car horns would be blar­ing at her. She would won­der: “Did that really hap­pen?” She hadn’t real­ized she was fall­ing asleep dur­ing the day. “You start to ques­tion everything,” she says.

Turn­er was tired all the time. She woke up with ter­rible head­aches. All the clues point­ing to­ward apnea were there, but she didn’t real­ize something might be wrong with her breath­ing dur­ing sleep un­til her hus­band told her. “He just lit­er­ally said that I stopped breath­ing, and I was like, ‘You’re kid­ding me, I don’t stop breath­ing.’ I had nev­er really heard of it at that point.”

On the ad­vice of her doc­tor, she was re­ferred for an overnight poly­so­m­no­graphy sleep study. It took some con­vin­cing (“You have to sleep in this un­known place the whole night, and I didn’t want to do it”), but she even­tu­ally agreed. Two minutes in­to Turn­er’s sleep study it had to be stopped. “I stopped breath­ing too many times,” she says.

After be­ing dia­gnosed, Turn­er was pre­scribed a CPAP (con­tinu­ous pos­it­ive air­way pres­sure) mask to wear at night. It’s cum­ber­some and “a mood killer,” she says, but it keeps her air­ways open. Since treat­ment, her life has turned around. She’s more alert. Her head­aches are gone.

The the­ory guid­ing Jean-Louis’s work is that sleep dis­orders like Turn­er’s are a sig­ni­fic­ant con­trib­ut­or to ra­cial health gaps in this coun­try—and if we could treat all those cases, there would be a mean­ing­ful re­duc­tion in health dis­par­it­ies. “Un­treated sleep apnea leads to car­di­ovas­cu­lar dis­ease if not death,” Jean-Louis says. “There are many times we go, we give talks in churches, and we hear stor­ies of people who died, and we al­ways say to ourselves, ‘You know, I think that was un­treated sleep apnea.’ We can’t have a 35-year-old Afric­an-Amer­ic­an male go to bed and not wake up the next day. That doesn’t make any sense.”

SLEEP APNEA IS the most ex­treme mani­fest­a­tion of the sleep­ing prob­lems that dis­pro­por­tion­ately af­fect black Amer­ic­ans. But fo­cus­ing on com­munity-based health edu­ca­tion—as Jean-Louis is do­ing—may help not just with sleep apnea but with oth­er sleep­ing prob­lems, too. And if his in­ter­ven­tions work, they could be scaled up.

In­deed, wheth­er it’s through com­munity health fairs or schools, sleep edu­ca­tion prob­ably needs to be­come more wide­spread. “What really brings me hope is that in a con­ver­sa­tion with new par­ents or a con­ver­sa­tion with middle-school stu­dents and their teach­ers, you can have a tre­mend­ous im­pact,” says Or­feu Bux­ton, a sleep-medi­cine re­search­er with ap­point­ments at Har­vard and Penn State who oc­ca­sion­ally gives talks at schools. The be­ne­fits of good sleep aren’t hard to mar­ket. “You talk about be­ing happy, look­ing bet­ter, be­ing health­i­er, all these dif­fer­ent things, and I don’t know which one is go­ing to hit for which per­son, but once you give the ex­plan­a­tion of how big an im­pact sleep has on ab­so­lutely everything, young­er people are turn­ing the corner, I think.”

For kids, Bux­ton thinks that hav­ing schools start later would en­cour­age healthy sleep habits at an early age. For adults, work­places can also ad­just: Bux­ton and col­leagues at Har­vard have found that in nurs­ing homes where man­agers were more sup­port­ive of work-life bal­ance, em­ploy­ees were more likely to get more sleep.

Both state gov­ern­ments and Wash­ing­ton could play a role by en­cour­aging em­ploy­ers to ad­opt com­pany well­ness pro­grams that re­ward good sleep. (Most crit­ic­ally, these pro­grams should seek to reach shift work­ers who live in an al­most con­stant state of jet lag.) In fact, at every level of gov­ern­ment, there are policy de­cisions—wheth­er on neigh­bor­hood noise levels or pub­lic safety or the place­ment of pub­lic hous­ing—that provide good op­por­tun­it­ies to con­sider, and per­haps im­prove, how people sleep.

One point of op­tim­ism is that this sub­ject, though re­l­at­ively new, is be­ing well-sup­por­ted by the NIH. The ma­jor­ity of the stud­ies cited in this art­icle re­ceived some fund­ing from the NIH, which has iden­ti­fied de­creas­ing health dis­par­it­ies as a re­search pri­or­ity. Since 1993, ac­cord­ing to Twery, there have been more than 10,000 NIH-fun­ded sleep re­search pro­jects pub­lished.

Ul­ti­mately, sleep may of­fer re­search­ers a way to at­tack seem­ingly even more in­tract­able health prob­lems—in­clud­ing those that dis­pro­por­tion­ately af­fect black Amer­ic­ans. “Not only might sleep be a po­ten­tial caus­al factor in health dis­par­it­ies mak­ing things worse, it might be a po­ten­tial place to help the situ­ation,” Grand­ner says. “If you take someone who is not get­ting enough sleep, and you in­crease their sleep, can that pre­vent some of these things”—obesity, dia­betes, heart dis­ease—“over time? That’s still an open ques­tion.”

Tom­fohr also sees some cause for op­tim­ism. “I don’t think this is totally fa­tal­ist­ic,” she says. “My hope is that this is ad­dress­able from mul­tiple levels—that we can identi­fy people who are at risk for sleep­ing poorly, and then we can do good in­ter­ven­tions to help them sleep bet­ter, so this isn’t a sen­tence to­wards get­ting car­di­ovas­cu­lar dis­ease, or get­ting sick, or get­ting dia­betes. I have a hope­ful feel­ing about this.”