SHIFT WORKERS WHO CONFINE EATING TO DAYTIME may have fewer mood symptoms (such as anxiety and depression) than those eating day and night. That’s the conclusion of a new study from Harvard’s Brigham and Women’s Hospital (USA). Today we explore eating time and mood disorders.
Shift workers represent 20 percent of the workforce in industrial societies. These workers are important in many domains, including factory work, hospital services, and other essential businesses.
They often experience a misalignment between the brain’s central circadian clock and daily behaviors, such as sleep/wake and fasting/eating cycles.
Today we explore whether the timing of food consumption can reduce mood vulnerability for those doing shift work (or having some other circadian misalignment such as jet lag).
Misalignment of the circadian clock
Do you do shift work? This type of job is associated with a misalignment between the central circadian clock in your brain and basic quotidian behaviors, including our sleep and wake and fasting and eating cycles.
Speaking to Medscape, senior study Sarah Chellappa, MD, Ph.D., explains: “Shift workers often experience a misalignment between their central circadian clock in the brain and daily behaviors, such as sleep/wake and fasting/eating cycles.”
She adds, “[Shift workers] also have a 1.25- to 1.4-times higher risk of anxiety and depression. Recognizing that meal timing is important for physical health and diet for mood, we sought to determine whether meal timing influences mental health.”
Would eating confined to the daytime help to prevent mood disruption, despite simulated night work?
The researchers designed a randomized clinical trial that included a 14-day circadian laboratory protocol. The study included 12 men and seven women aged 21 to 31.
All the volunteers had forced desynchrony with dim light for four “days,” each consisting of 28 hours. This maneuver naturally led to a four-hour misalignment between the subjects’ central circadian clocks and external behavioral and environmental cycles.
By day four, all were misaligned by 12 hours (compared to the first day). The researchers then randomly assigned the participants into two groups:
- The control group had daytime-only meals.
- The daytime-nighttime feeding group had meals taken during both daytime and nighttime.
Circadian clock and meal-timing results
As published online in the Proceedings of the National Academy of Sciences, the results are as follows:
Depression- and anxiety-like mood levels increased by about one-quarter (26 percent) and over one-sixth (16 percent) among the daytime/nighttime eaters. The daytime-only group had no such increase.
The study authors offer that the study findings imply that meal timing had moderate to large effects on depression- and anxiety-like mood levels during night work. These changes appeared associated with the degree of internal circadian misalignment.
The findings imply that meal timing had “moderate to large effects on depression-like and anxiety-like mood levels during night work and that such effects were associated with the degree of internal circadian misalignment.
Let’s end with the words of study author Frank Scheer, Harvard Medical School Professor of Medicine and Director of the Medical Chronobiology Program in the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital (USA):
“Our findings provide evidence for the timing of food intake as a novel strategy to potentially minimize mood vulnerability in individuals experiencing circadian misalignment, such as people engaged in shift work, experiencing jet lag, or suffering from circadian rhythm disorders.”
I am fascinated by recent studies exploring the relationship between nutrition and mood states. Thank you for joining me today in this look at eating time and mood disorders such as anxiety and depression.
Disclosures
The National Institutes of Health funded this study. The Alexander Von Humboldt Foundation funded individual investigators, and the American Diabetes Association provided funding to individual researchers.
The information I provided in this blog is for educational purposes only and does not substitute for professional medical advice. Please consult a medical professional or healthcare provider if you seek medical advice, diagnoses, or treatment. I am not liable for risks or issues associated with using or acting upon the information in this blog.
