Long-haul brain drain

Abstract

Too much jet setting can shrink your brain and impair your cognitive ability, according to new research by Kwangwook Cho [Nature Neurosci. (2001) 4, 567–568]. Brain scans showed that airline cabin crew who had less than five days to recover between long-haul flights had smaller right temporal lobes than those who were allowed longer recovery times. The short recovery group also performed worse on a spatial memory test that depends on the temporal lobe. The brain shrinkage was correlated with elevated levels of cortisol. Cho suggests that frequent shifts between time zones without sufficient time for readjustment disrupts the delicate relationship between the day–night cycle and our bodies’ circadian rhythms, leading to increased cortisol levels. As Cho explained to TICS, ‘disruption of circadian rhythms causes physiological and physical stress and high stress levels have an impact on brain function. Brain atrophy may be caused by high stress hormone levels.’ The airline crew study suggests that after five years of increased cortisol, cognitive deficits and brain shrinkage become apparent. HJB