Flight risk

Vegetarian Times, August, 2001 by Maria Rabat

The jet-setting life may seem charmed, but a new study suggests that it could be hazardous to your health. Anyone who has flown through several time zones has probably experienced jet lag, that out-of-sorts feeling fueled by fatigue, irritability and mental exhaustion. A new study published in Nature Neuroscience (June, 2001) indicates that repeated exposure to these symptoms may lead to a more serious condition. Neurologists at the University of Bristol, England, found that frequent jet-lag sufferers may be at risk for brain shrinkage and memory impairment. And it's not just airline employees who are likely to suffer such a fate. Results of the study imply that anyone who repeatedly disrupts his or her natural internal body clock, or circadian rhythms, are susceptible, including frequent travelers, graveyard-shift workers and hospital personnel.

For the study, researchers recruited 20 flight attendants between the ages of 22 and 28 who make regular flights across seven time zones. Half of the subjects spent five days or fewer in their home time zone between trips, the other half spent 14 days or more at home. Participants then submitted to memory tests and magnetic resonance imaging (MRI) of their brains.

Results indicated that the size of the right temporal lobe, which controls visual and spatial memory, was slightly smaller in the flight attendants who spent less time at home. And the ones who flew more frequently had slower reaction times and scored significantly lower on the memory test.

Previous research has established that the human body runs best on regular rhythms of daylight and darkness and is thrown out of sync when circadian rhythms are disrupted. This new British study not only supports these findings but has gone a step further by discovering how the brain reacts to body clock changes.

Summer travelers crossing multiple time zones should take note: It appears that our brains need at least 10 days to recover from such a stress. So you may want to schedule that post-vacation vacation now.