Shift work can age the brain by 6.5 years, says scientific study

[BalanceOfPower]

Shift work can age the brain by 6.5 years, says scientific study

PUBLISHED : Tuesday, 04 November, 2014, 9:45pm
UPDATED : Wednesday, 05 November, 2014, 3:37am

Agence France-Presse in Paris

Researchers found an association between shift work and "chronic cognitive impairment". Photo: Simon Song

People who work shifts for 10 years or more may suffer loss of memory and brain power, said a study that also warned of safety concerns in high-risk jobs.

The effects on brain function can be reversed, the team wrote in the journal Occupational & Environmental Medicine, but this may take at least five years.

The research is the latest to highlight the dangers of shift work, which disrupts the body's internal clock and has previously been linked to health problems such as ulcers, cardiovascular disease and some cancers.

But little has been known about its potential impact on brain function.

Researchers tested more than 3,000 current or retired workers in a variety of sectors in southern France in 1996, 2001 and 2006 for long- and short-term memory, processing speed and overall cognitive abilities.

About half of the trial subjects, aged either 32, 42, 52 or 62 when they were first tested, had worked shifts - classified as night work or shifts that alternated between morning, afternoon and night.

Comparing the change in test results over time, and between the two groups, the researchers found an association between shift work and "chronic cognitive impairment".

"The association was stronger for exposure durations exceeding 10 years" of shift work, which they said was equivalent to an additional 6.5 years of age-related decline. The data also showed that "recovery of cognitive functioning after having left shift work took at least five years".

The study could not prove conclusively that shift work was the cause of the cognitive decline, said the authors, and though it seemed "highly plausible".

The findings raised "potentially important safety consequences not only for the individuals concerned, but also for society," the scientists concluded, pointing to "the increasing number of jobs in high-hazard situations performed at night".