Circadian Disruptions Alter Metabolism, Affecting Recovery Time

Recent research from the University of Surrey, in collaboration with the University of Aberdeen, has shed light on how disturbances to our circadian rhythm—like those pesky bouts of jet lag—can affect our metabolism.

Interestingly, these disruptions don’t seem to have as strong an impact as the effects of sleepiness and changes to our brain’s master clock.

The Study Design

The study, led by Professor Jonathan Johnston from the University of Surrey and Professor Alexandra Johnstone from the University of Aberdeen, utilized a carefully controlled experiment where participants experienced a five-hour shift in their bed and meal times.

Published in the journal iScience, the findings reveal that even minor changes to our daily schedules can lead to notable metabolic shifts.

These include diminished energy expenditure during digestion, fluctuations in blood sugar and lipid levels, and a delay in how quickly the stomach empties after breakfast.

Recovery and Implications

A silver lining to these metabolic changes is their reversibility.

Most people returned to their baseline metabolic functions within two to three days after experiencing the five-hour shift.

However, the recovery of the brain’s circadian clock, along with feelings of fatigue and alertness, took longer, lingering for five days or more even after the time adjustment.

Professor Johnston emphasizes the study’s implications for our contemporary lifestyles, where travel and shift work are increasingly common.

While even slight shifts in time can disrupt our metabolic functions, the disturbances from jet lag resolve more quickly than those tied to sleep and alertness.

Understanding how circadian rhythms affect our health could empower people to make more informed lifestyle choices.

By optimizing our daily routines around sleep and meals, we may significantly enhance our health and overall well-being.

Study Details:

• Title: Short-term changes in human metabolism following a 5-h delay of the light-dark and behavioral cycle
• Authors: Alan Flanagan, Leonie C. Ruddick-Collins, Barbara Fielding, Benita Middleton, Johanna von Gerichten, Michael Short, Victoria Revell, Jeewaka Mendis, Claus-Dieter Mayer, Peter J. Morgan, Alexandra M. Johnstone, Jonathan D. Johnston
• Journal: iScience
• Publication Date: November 19, 2024
• DOI: 10.1016/j.isci.2024.111161