Horacio de la Iglesia doesn’t always practice what he preaches.
The sleep scientist and UW professor of biology, whose influential sleep research helped demonstrate the benefits of delaying school start times for Seattle high schoolers, knows that he should go to bed at roughly the same time each night.
But on weekends, he likes to stay up late (at least, late by middle-aged professor standards).
He knows that exposure to natural light early in the day is directly correlated to more and better sleep.
But he doesn’t always want to rush out the door first thing in the morning—although, since no one else in his household is generally raring to walk Morena, the family mutt, in the early morning, the job almost always falls to him.
And he knows that excessive exposure to bright electric light and screens late in the evening wreaks havoc on our body’s ability to regulate our circadian rhythms, making it difficult to prepare for and go to sleep.
But, like many of us, there are evenings spent working (or streaming, or scrolling) at the computer or on his phone—later than he probably should.
Horacio has been studying sleep and circadian rhythms for more than 30 years, focusing on human sleep for the last dozen. He knows as well as anyone what constitutes good sleep hygiene and is probably better than most at following those guidelines.
But like the doctor who occasionally indulges in a donut or the dentist who enjoys hard candy, he is fallible.
“I try to practice good sleep hygiene,” he said. “I don’t have caffeine after noon, try not to go to bed too early or too late. But some days that’s easier than others. Too, there’s the impact of getting older.”
As people age, they spend less time in deep sleep, tend to wake up more frequently, and need to make more nighttime trips to the bathroom—all of which results in less sleep.
The good news is, while healthy sleep habits are indicative of overall health and well-being—indeed, chronic sleep deprivation is consistently linked to anxiety, depression, obesity and addictive behavior— regularly sleeping well is, as the popular saying goes, not a sprint but a marathon.
Crustaceans’ circadian rhythms
As an undergraduate at the University of Buenos Aires (UBA), in his native Argentina, Horacio became interested in the biology of animal behavior after noticing burrowing patterns among crustaceans.
Most Argentinians—actually, gourmands the world over—prize the Southern king crab for its tender and sweet white meat, shelling out (pun intended) big bucks for the delicacy.
For Horacio, the crabs’ synchronous cycles of light and dark burrowing behavior shaped the course of his professional life.
He took classes in ecology and molecular biology, gravitating toward the hard sciences, before settling on a research-intensive biology track. Under faculty mentorship, Horacio began conducting research into how tides regulated the crabs’ behavior and daily rhythms, even bringing the crabs to campus with him to study their behavior.
After graduating from UBA, Horacio moved to the U.S. to attend the University of Massachusetts at Amherst for graduate study, pursuing a PhD in neuroscience and behavior.
Though Horacio and his wife, also a UW professor, and their family have visited Argentina many times since then, they never returned for good.
While in graduate school, and as a post-doctoral researcher at UMass Medical School, Horacio’s research zeroed in on mammals, investigating the interplay in the brain between the master circadian clock and the centers that control reproduction.
After teaching briefly at Harvard, Horacio was hired at UW in 2003. Happy to leave the frigid winters of Boston behind, he packed up his young family and headed west.
At UW, Horacio would again refocus his research, this time examining the physiological and behavioral impact of sleep not on crustaceans, nor animals, but humans.
Let the kids sleep
For the better part of a decade, Horacio and his lab team conducted research on sleep in Seattle-area teenagers—a subject with which he was personally familiar, having two teenagers in the house at the time.
His research confirmed that, like teenagers across the U.S. and perhaps around the world, Seattle-area high schoolers were not getting adequate sleep. In fact, in one study, he found that of 182 teens measured, only two of them slept the nine hours their bodies required for optimal functioning.
That is, fewer than 2% of Seattle teens are getting enough sleep.
Horacio explained three key considerations in what many sleep scientists are calling an epidemic of sleeplessness: excessive exposure to artificial light and screens late in the evening, a lack of morning exposure to daylight—which is particularly manifest during Pacific Northwest winters—and changes with teens’ biological clocks during and after puberty.
There really is a physiological reason for teens’ night owl tendencies.
However, it’s no secret that our waking environments are heavily influenced by artificial light—not just teens, but all age groups—and we pay the price in sleep.
Even filtered, the light emitted by screens is highly stimulating and inhibits, among other things, the brain’s natural production of melatonin, which cues us to get ready for sleeping.
Of course, parting teens—or anyone, really—from their phones in the evenings is easier said than done. So Horacio joined with parents, teachers and other sleep scientists to persuade Seattle Public Schools to start school later for middle and high school students, by nearly an hour, so that teens could sleep in longer.
The result? High schoolers in Seattle gained an average of 34 minutes of sleep per night—an enormous increase by sleep medicine standards, with subsequent gains in school attendance, academic achievement and overall well-being.
Horacio is delighted to see later start times adopted by other school districts around the country, with tangible effect on the epidemic of “Generation Sleepless.”
But there is another sleep-snatching obstacle that he has been working hard to address, and it’s proving a challenge: daylight saving time.
Like Monday morning every day
Twice a year, like clockwork, when most Americans spring forward or fall back, Horacio and other nationally recognized sleep scientists field media inquiries about the risks and rewards of daylight-saving time (DST).
It’s a debate that has been going on for decades—at the federal level, at the state level, at kitchen tables and barstools across the country. When the U.S. tried adopting DST permanently in the 1970s, people hated it. Less than a year after the measure was enacted, permanent DST was scrapped and standard time was restored.
Evidently, we didn’t learn our lesson from that experiment: earlier this year, the U.S. Senate unanimously voted in favor of permanent DST in the Sunshine Protection Act, which would have permanent DST go into effect in October 2023. The bill is currently stalled in the House of Representatives.
According to Horacio, the risks of permanent DST far outweigh the rewards. In fact, permanent DST would be downright detrimental to our health.
“You may think that the extra hour of evening light we gain with DST is good for you,” Horacio explained in a Seattle Times article. “But research shows that the hour of morning light we miss out on under DST is unhealthy for your body and mind.”
While any exposure to natural light will help stave off winter depression and seasonal affective disorder (SAD), it’s morning light that really packs a punch for our biological clocks, promoting an earlier bedtime and natural early morning wake time.
But those four months of winter during standard time are already dark, especially in northern latitudes, and adding another hour of darkness in the morning—the sun wouldn’t rise until 9 a.m. on Seattle’s shortest day of the year with permanent DST—would mean very little opportunity for natural morning light.
And there’s that seemingly never-ending cloud cover to contend with, too. You know, a typical Seattle day from November through March.
And the negative impacts of year-round DST would be even greater—particularly for those tired teens—because of the pervasiveness of screens and artificial light that stimulate the circadian system during the evening.
Most sleep scientists affiliated with the American Academy of Sleep Medicine and Sleep Research Society, including Horacio, support the implementation of permanent standard time, rather than permanent DST. Permanent standard time, Horacio says, “more closely aligns with the solar day, when the sun is at its highest point at noon. Our body naturally syncs to that time.”
“Being on daylight saving time in the middle of the winter,” he said, “would be like Monday morning every day for the rest of your life.”
Like teenagers, there is another group of people for whom chronic sleep deprivation is an epidemic and a public health crisis. Unlike teenagers, however, this group is under-researched and largely ignored.
“It’s a problem that has never been tackled, homelessness from a sleep perspective,” Horatio explained.
It is difficult to ignore the pervasive homelessness in our region. There are many complex and intertwined reasons for homelessness, with the lack of affordable housing in the Pacific Northwest being a major driver.
Four years ago, while walking past a tent in a homeless encampment in Seattle, Horacio saw a sign—literally—that stopped him in his tracks. It read “Sleep: A Human Right.”
He remembered thinking, “Wow. I must study this.”
Together with graduate student researcher Alicia Rice, Horacio launched The Sleep and Homelessness Project to investigate the relationship between sleep quality, chronic homelessness and health disparities.
“We discovered that a big issue facing homeless young adults, maybe even the main issue, is not food, not safety, but sleep,” Horacio explained. “Everything revolves around getting sleep, and those experiencing homelessness frequently do not get enough.”
Partnering with other UW faculty and with local shelters, the research team uses wrist actigraphy activity tracking technology (like a FitBit) to monitor sleep patterns and circadian rhythms in unhoused young adults.
The team also conducted a series of candid interviews with several study participants, who were eager to talk about the role sleep—or lack of it—plays in their lives.
“They want to talk about sleep,” Horacio said. “It’s a fundamental human activity and the lack of it is a matter of public health.”
Although the research is still in its nascent stages, Horacio is optimistic that its results will effect greater public awareness about sleep health disparities in homeless populations, perhaps ultimately influencing policy around affordable housing.
In a recent study, Horacio and his team demonstrated that, for most people, sleep cycles oscillate along with the waxing and waning of the moon. When the moon is waxing and full, people go to bed later and sleep less—up to 90 minutes less than normal.
Interestingly, researchers observed these sleep variations in both urban and rural settings; the latter, collected in northern Argentina not terribly far from Horacio’s hometown (in the above photo, Horacio is fitting a rural Argentinian with wrist actigraphy for this research).
Their data suggest that our natural circadian rhythms may be synchronized with the phases of the lunar cycle, even in highly urbanized areas such as Seattle.
The research suggests that sleep could be modulated not just by moonlight—complicated, in the Pacific Northwest, by our area’s unpredictable cloud cover and light pollution—but also by other geophysical forces, such as geomagnetism and gravitation.
Though not strictly in his field, investigating to what extent these natural forces are impacting human sleep is highly compelling to Horacio. He has consulted with researchers at NASA about the potential effects of the lunar cycle on astronauts in space, for whom sleep is notoriously difficult.
“This is very cutting-edge research,” he said. “The implications are exciting. Who knows? Maybe this work will inform a future Mars mission.”
Soaking up the sun
In the shorter term, Horacio and his family are looking forward to spending the holidays with relatives in Argentina—where it is summertime, and temperatures are in the low 80s.
Both Horacio and his wife love working at UW and making their home in the Pacific Northwest.
“We are so fortunate to work at an excellent university and have such a high quality of life in this area,” Horacio said. “You can find anything you need here: technology, knowledge, nature, culture. We’re not missing anything in Seattle.”
They enjoy spending time at Olympic Peninsula and anticipate visiting this spring to do some hiking. Horacio, a pre-pandemic gym-goer, is trying to get back into the groove of working out and running regularly.
And, as the weather improves and the days start getting longer, they will undoubtedly be out in the garden, soaking up what daylight Seattle has to offer.
After all, as Horacio preaches, exposing oneself to natural light early in the day is key to better sleep.