Your body’s stress hormone, cortisol, goes up and down based on the time of day and whether you’re in light or dark, not just because you’re stressed.
Scientific Claim
Cortisol secretion follows a circadian rhythm entrained primarily by environmental light exposure, with secondary modulation by feeding timing and psychological stress.
Original Statement
“Cortisol is circadian. It is environmental. It is not just stress. We respond to the light. We respond to the dark. We respond to the stress. We respond to the food. And it all ties in with our adrenal glands and cortisol.”
Context Details
Domain
neurology
Population
human
Subject
Cortisol secretion
Action
follows
Target
a circadian rhythm entrained primarily by environmental light exposure, with secondary modulation by feeding timing and psychological stress
Intervention Details
Evidence from Studies
Supporting (2)
Even though the mice were exposed to the same light schedule, eating too much fatty food messed up their body’s daily cortisol rhythm, showing that what you eat can interfere with your body’s internal clock.
Even when scientists messed up the cows' light schedule, their cortisol levels still rose and fell at the same time each day—showing that light, not just food or stress, is the main clock that controls cortisol.