A new scientific study published in the journal Frontiers in Endocrinology shows that working night shifts for many years is associated with significant molecular biological changes in the activity of key genes responsible for the body's biological clock among healthcare workers.
The study, conducted on 93 female healthcare employees, indicates that those who worked night shifts, compared with their colleagues who only worked day shifts, showed a significant decrease in the expression level of three vital genes (CLOCK), (TEF) and (PER1) in addition to the gene (YY1).
According to these findings, this decrease was more pronounced among female staff whose history of night service ranged from 13 to 35 years or who had experienced more than 1,000 night shifts.
Potentially carcinogenic
This biological disruption is attributed to direct exposure to artificial light at night and the continual alteration of sleep patterns; conditions that lead to suppression of melatonin secretion and disruption of the usual coordination between the internal biological clock and daily activities.
This imbalance is associated with health consequences including increased sleep disorders and disturbances in metabolism and immunity; to the extent that the International Agency for Research on Cancer has classified night shift work as a probable carcinogenic factor for humans.
Researchers emphasized that the gene (TEF) has the greatest ability to distinguish between night and day shift workers; a matter that indicates the cumulative effect of years of biological stress on regulatory gene networks.
Although the results of this study confirm the existence of a clear molecular genetic signature for long-term night work, the researchers stressed the need for longitudinal studies in the future to confirm whether these genetic changes are permanent or reversible after returning to a normal work schedule.