Risk of cancer through shift work?
Dr. Andrea Bannert has been with since 2013. The doctor of biology and medicine editor initially carried out research in microbiology and is the team's expert on the tiny things: bacteria, viruses, molecules and genes. She also works as a freelancer for Bayerischer Rundfunk and various science magazines and writes fantasy novels and children's stories.
More about the experts All content is checked by medical journalists.Working at night is not only exhausting, it is also good for your health. Shift work may even promote cancer. The reason could be inhibited repair mechanisms in the cells.
Anyone who looks after the sick at night, works on the construction site or in the factory, sits in the call center, ensures security or does other shift work, is constantly working against their internal clock. Daytime sleep is usually not as restful as normal nighttime sleep: On average, shift workers only find 5.5 hours of rest, day workers, on the other hand, have a significantly longer recovery period of 7.5 hours.
No wonder then that night work and the associated lack of sleep promotes obesity, increases the risk of cardiovascular problems and diabetes and is even suspected of promoting cancer.
Changed hormones during daytime sleep
Parveen Bhatti and his colleagues at the Fred Hutchinson Cancer Center in Seattle have taken a closer look at the latter connection. They asked themselves: what could be the reason shiftworkers are more likely to develop cancer? Their starting point was the sleep hormone melatonin. Since this substance is increasingly released in the dark, the researchers found only around a third of the normal melatonin content in their urine after the sleep phase of 50 test shift workers. Bhatti's assumption: The unnatural sleep rhythm could have other effects that can be detected in the urine.
Braked gene repair
In fact, the researchers found a certain substance in the urine of nocturnal people much less often than in a control group that was able to follow their natural biorhythm: the compound 8-OH-dG. It is always excreted when the cells have successfully repaired certain damage to the genetic material, i.e. the DNA. It is known that cell repair usually gets going especially at night. Shift work apparently hinders genetic self-healing: after a night shift, on average, only 20 percent of the repair indicator is found - errors in the genetic code are therefore repaired to a lesser extent.
In a next step, the researchers now want to clarify whether the sleep hormone melatonin actually activates the patching of the genetic material. If this is confirmed, Bhatti sees a way to prevent it: "Possibly an additional dose of melatonin could protect shift workers from potentially carcinogenic DNA damage."
Damage in the genes
The development of cancer is a complex process in which various factors play a role. The starting point is always the genetic makeup. If changes occur there, so-called mutations, it can happen that the cells proliferate - a tumor grows.
Tags: anatomy prevention fitness
