Three American scientists have won the Nobel Prize in physiology or medicine for their discoveries of the microscopic biological machinery that controls the circadian rhythm, or the 24-hour body clock.
Humans, plants, and animals are all ruled by an internal clock that runs on a 24-hour, light-dark cycle in sync with the sun. And there’s not just one of these clocks inside us: They’re in every single cell of every organism — from a tiny bacterium to a large redwood tree.
In humans, these biological clocks anticipate various activities throughout the day, from waking up to sleeping and eating, by regulating things like hormone levels, temperature, and metabolism. Our circadian rhythm is intimately tied to our health and well-being (which helps explain why jet lag or a late-night shift work can be so draining and harmful).
The three Nobel laureates — Jeffrey C. Hall of the University of Maine, Michael Rosbash of Brandeis University, and Michael W. Young of Rockefeller University — “were able to peek inside our biological clock and elucidate its inner workings,” the Nobel Prize Committee said in a press release. “Their discoveries explain how plants, animals, and humans adapt their biological rhythm so that it is synchronized with the Earth's revolutions.”
In the 1970s, another pair of researchers — Seymour Benzer and his student Ronald Konopka — published their findings of an unknown gene called “period” that controlled the circadian rhythm of fruit flies.
Hall and Rosbash, who were working as collaborators at Brandeis University near Boston, as well as Young, who was (and still is) based at the Rockefeller University in New York, decided to dig deeper. By 1984, they were able to isolate the period gene. Hall and Rosbash also discovered the protein the period gene encoded, which appeared to build up during the night and degrade during the day on a circadian rhythm.
The trio went on to make other discoveries that explained how circadian rhythms are created and sustained. They also found additional proteins that activate the period gene.
“The paradigm-shifting discoveries by the laureates established key mechanistic principles for the biological clock,” the Nobel committee said. “During the following years other molecular components of the clockwork mechanism were elucidated, explaining its stability and function.”
These discoveries were seminal to the field of chronobiology
Long before Hall, Rosbash, and Young were doing their research, scientists suspected we were controlled by a circadian rhythm. But, the Nobel committee said, “Since the seminal discoveries by the three laureates, circadian biology has developed into a vast and highly dynamic research field, with implications for our health and wellbeing.”
Their findings have had major implications for health research and helped establish what’s now a growing field of science called chronobiology.
In recent years, researchers have discovered that each of us has a unique, genetically determined “chronotype,” or clock that programs our ideal sleep time in the 24-hour cycle. This discovery helped clarify why there are true “morning people” and true “night owls,” and why, as Vox’s Brian Resnick has argued, people should be able to set their own work schedules.
Researchers even coined the term “social jet lag” to describe the effects of shifting one’s sleep cycle by even a couple of hours. (Even moving people’s sleep cycle by one hour each day made participants in a study look prediabetic after a three-week trial.)
Researchers studying chronobiology have also found that eating at night can be extra problematic for health, since our bodies aren’t primed to cope with the glucose load from the food in the evening. We usually eat a meal after waking up, so our bodies adapted to produce the most insulin in the morning.
There’s also emerging work that suggests our circadian rhythm can influence how we metabolize medicines: The timing of taking a drug during the day may control its effectiveness.
So we are slaves to our circadian system, and Hall, Rosbash, and Young helped us understand how and why.
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