EYE-OPENER

The claim
Caffeine helps prevent night-time accidents on the job.
The facts
About 8.6 million Americans work night shifts,and for many of them fatigue is a serious problem.
Night workersfrom health professionals to air traffic controllersexperience more accidents and injuries on the job,report more medical errors and face a greater risk of car crashes after their shifts. Some of the most high-profile accidents linked to human error have occurred on the night shift,including the Exxon Valdez disaster and the nuclear accidents at Chernobyl and Three Mile Island. The recent BP oil spill also occurred at the start of an overnight shift,though the cause is still under investigation.

Scientists have tried melatonin,prescription medications and light therapy to help relieve so-called shift work disorder,caused by disruptions in the bodys circadian rhythm. But research shows that nothing seems to work quite as well as caffeine.

In a study published in the latest issue of The Cochrane Library,scientists pooled data from 13 previous studies on performance among shift workers. The studies also looked at performance on tasks like driving and neuropsychological tests. Ultimately,they found that caffeine worked better than a placeboand even napsat reducing errors and improving performance on tasks including those involving memory,attention,perception,concept formation and reasoning.
Another study at Harvard Medical School found that caffeine worked best in small doses spread out over time.
The bottom line: Caffeine is an effective aid to night-time job performance.
NYT