Identified Phenomenon that Causes Night Shift to Be Harmful to the Body

Except for the millions of shift workers who toil through the night, sleep calls as night falls. Their health deteriorates as the rest of us slumber.

Shift workers frequently struggle with weight gain, diabetes, cancer, depression, and poor heart health because they are battling their body clocks to stay awake when they should be resting and eating when their metabolism is naturally slowing down.

A person's health is severely affected by this misalignment because it throws the body's regular circadian cycles out of balance.

A new study in rodents has identified one underlying mechanism that may cause changes in hunger when sleep-wake cycles and day-night cues don't coincide. Research has shown that when you eat has a meaningful impact on your health.

Researchers from the University of Bristol in the UK looked into how hormones associated with sleep-wake cycles and daily feeding habits in rats related to each other. They discovered that disrupted circadian rhythms had a significant impact on the animals' eating behaviour.

By administering injections of the hormone corticosterone to rats either in phase with or out of phase with light-dark signals, the researchers tampered with the animals' typical circadian rhythms.

The glucocorticoid hormone corticosterone, which rises sharply in the minutes before waking and then progressively falls during the day, is to mice what cortisol is to us.

The same quantity of food was ingested daily by rats with regular rhythms that were thrown off by improperly timed corticosterone surges, the in-sync animals, and a control group of rats that did not receive any infusions. But when they should have been sleeping, they consumed approximately half of their normal food consumption.

Even though the timing was changed, there was no weight gain or increase in fat mass, but there was a significant change from their regular feeding patterns, which the researchers linked to increased activity at the wrong periods in the genes that control appetite.

When corticosterone levels were out of whack, several genes that make proteins that increase appetite were expressed more frequently in rats than they would normally be. The study discovered that this, along with a decline in genes that regulate hunger, likely caused an increased urge to eat much more during the animals' sedentary period of the day.

According to Stafford Lightman, a neuroscientist at the University of Bristol and the study's lead author, "When we disrupt the normal relationship of corticosterone with the day-to-night light cycle, it results in abnormal gene regulation and appetite during the period of time that the animals normally sleep."

All of this information is useful, but what can shift workers do to lessen the negative effects of their work schedules on their health if it turns out that the same issue also occurs in humans?

Nurses, security officers, and other shift workers are more aware than most of how difficult it may be to adhere to the standard advice to combat the negative health effects of their important work: get some sunlight, fit in some exercise, and eat meals at set times.

These suggestions are well supported by the available research, which demonstrates that restricting meals to the daytime may help prevent the mood disturbances caused by night labor. Human experiments, which are more informative than animal studies, have demonstrated this.

In a three-month trial of firefighters, time-restricted eating, which restricts the hours when people eat but not necessarily the calories ingested, also improved markers of cardiovascular health.

However, as University of Bristol endocrinology expert and study author Becky Conway-Campbell recognizes, brain impulses that cause increased hunger can be "difficult to override with discipline or routine".

As a result, the team is developing trials to investigate potential pharmacological treatments that could reduce disordered eating, based on what they now understand about how improperly balanced proteins can increase appetite at night.

Although lifestyle changes are frequently preferable to drugs, they must be practical for people to carry out.