The human body has a natural circadian rhythm, a 24-hour cycle that regulates various physiological processes, including sleep-wake patterns, hormone production, and metabolism.
It’s estimated that approximately 14% of the workforce engages in night shifts. Circadian misalignment in shift workers is linked to health issues such as heart disease, weakened immune function, metabolic diseases, stroke, and cancer, as well as poor quality of life and higher healthcare costs.
Grizzly Bears’ Genetic Study Offers Insights for Humans
In a genetic study conducted by Washington State University, researchers discovered that Grizzly bears maintain circadian rhythms even during hibernation, showing minimal ill effects despite losing up to 30% of their body weight.
Hibernating bears exhibit fluctuating energy production in a daily pattern, despite not eating for months. Their ability to maintain energy peaks during hibernation without detrimental health effects highlights the flexibility of circadian rhythms.
In the study, researchers examined the cellular-level expression of the internal body clock in bears. Cell samples from six bears were collected during both active and hibernating periods, cultured, and compared. The analysis revealed rhythmic circadian activity in hibernating bear cells, indicating that cellular energy (adenosine triphosphate or ATP) production followed a 24-hour cycle, albeit with lower peaks and valleys.
Insights for Managing Circadian Disruptions in Humans
Researchers believe that the remarkable physiology of these “extreme shift workers” could provide insights into how humans might effectively adapt to circadian rhythm disruptions.
Researchers discovered that bears possess the ability to suppress their circadian rhythm without halting the internal clock. The researchers suggest that tapping into this capability could aid humans in adapting to schedules that necessitate working during the ‘biological’ night and sleeping during the day.
