Page 68 - Prevention - USA (April 2020)

SCI E NCE

Here’s how this system, known as
the circadian rhythm, works: As the
sun begins to rise, “the master clock
receives light input directly from the eye
and uses that information to synchro-
nize the 24-hour day,” says Melissa A.
St. Hilaire, Ph.D., an associate biostatis-
tician in the division of sleep and circa-
dian disorders at Brigham and Women’s
Hospital in Boston. That helps regulate
several hormonal processes. Melatonin,
which allows us to sleep, plummets, and
cortisol, which revs up energy, increases.
Hours later, as night falls and the sun
disappears, melatonin levels begin to
rise again, winding us down.
But with the advent of lightbulbs,
television, and now smart technology,
humans are staying up long past sunset,
throwing off our internal clocks.
“Light is flooding our eyes when it’s not
supposed to,” says Gena Glickman,
Ph.D., director of the Chronobiology,
Light and Sleep Lab at Uniformed
Services University of the Health Sci- IT MAY AFFECT YOUR GUT: Nearly 40%
ences in Bethesda, MD. “We spend our of people who suffer from IBS, which
days in offices with fluorescent lights includes constipation and/or diarrhea
and no windows, then go home and and other GI difficulties, frequently
spend our evenings looking at screens experience sleeplessness. Researchers
filled with short-wavelength light, are exploring whether circadian dys-
sometimes referred to as blue light.” regulation might impact the trillions of
More than just your sleep can suffer bacteria in the gut, known as the micro-
as a result of this onslaught of unnatu- biome, and if so, whether supplementa-
ral light—it can throw off the secondary tion with oral probiotics might counter
clocks in cells in the heart, gut, muscles, some of the damage. If so, probiotics
and more. Here are some surprising may one day be prescribed to protect
ways in which your circadian rhythm shift workers, those who serve in the
influences your health. military (who frequently operate under

66 PREVENTION.COM • AP R I L 2020