Changes in work shifts or other nonstandard work schedules increases the risk of obesity and diabetes and other metabolic disorders, which ultimately also raises the risk of heart diseases, stroke and cancer.
A new study conducted at Washington State University dispelled the belief that the metabolic disruption in shift workers is driven primarily by the brain’s master clock, which normally keeps our bodies on a day-night cycle and uses light cues to synchronize the rhythms of the body’s organs and tissues.
Instead, the study revealed that separate biological clocks (so-called peripheral oscillators) in the liver, gut and pancreas have a mind of their own.
The team collected blood samples from healthy volunteers who had just completed either a simulated day shift schedule or a simulated night shift schedule.
The investigators then analysed the blood samples for metabolites, products of chemical reactions involved in digestion, such as the breakdown and oxidization of food molecules, as well as in other metabolic processes in cells and organs.In an analysis of 28 published studies, night shift work was associated with a 29% increased risk of becoming obese or overweight. The findings, which are published in Obesity Reviews, suggest that modifying working schedules to avoid prolonged exposure to long-term night shift work might help reduce the risk of obesity.
In the analysis, night shift workers had a higher frequency of developing abdominal obesity than other obesity types. Permanent night workers demonstrated a higher risk than rotating shift workers.”Globally, nearly 0.7 billion workers are engaged in a shift work pattern. Our study revealed that much of the obesity and overweight among shift workers is attributable to such a job nature,” said Dr. Lap Ah Tse, senior author of the study. “Obesity has been evident to be positively associated with several adverse health outcomes, such as breast cancer, cardiovascular diseases.”hey found that, following the night shift schedule, 24-hour rhythms in metabolites related to the digestive system had shifted by a full 12 hours.”No one knew that biological clocks in people’s digestive organs are so profoundly and quickly changed by shift work schedules, even though the brain’s master clock barely adapts to such schedules,” said co-senior author Hans Van Dongen.
