Long term shift work has a permanent negative effect on the brain damaging cognitive ability and memory, a new study has revealed.

Working shifts has significant negative effects on the brain, a new study has shown. Image via Medic Cast.

The study found clear links between shift work and impairments in memory and thinking (cognition). People who worked in shifts for 10 years or more have, on average, an extra 6.5 years fall in memory as well as thinking skills. Scientists are not sure if it’s the shift work itself that’s causing the decline, or rather the stress of having to constantly change and adapt your schedule.

Jean-Claude Marquie, the research director at the National Center for Scientific Research at the University of Toulouse France says that while the effects are permanent even after shift work has ended, moving on to a regular program can still help you recover from these negative effects. The study found that after working 10 years or more in shifts, the recovery time is typically around 5 years.

“Shift work chronically impairs cognition, with potentially important safety consequences not only for the individuals concerned, but also for society,” say the authors, led by Marquie.

Many reports have suggested that shift work may have negative effects on the brain, and while there have been studies on the issue, they have been relatively few. In 2001, Scott Davies, a PhD student at the time, showed a correlation between night shifts and the risk of beast cancer. In 2002, one year later, Torbjörn Åkerstedt revealed something which surprised no one: shifts can cause major disturbances in sleep patterns and affect the circadian rhythms. Another worrying study was published in 2001; the researchers observed over 27,000 people and showed that obesity and high levels of triglycerides cluster together more often in shift workers than in day workers, and they suspected a connection between metabolic syndromes and shift works.

This new study goes in the same line, showing that shifts have potent negative effects, and furthermore, it shows that the effects are chronic. Marquie and colleagues tracked mental abilities of over 3,000 people from various regions in France who worked in a broad range of fields; about 1,500 of them worked in shifts. Tests including gauge memory, processing speed and thinking ability were conducted.

The results clearly highlighted that shift-workers had overall lower memory as well as thinking ability scores as compared to those who didn’t shift work.