12

A recent article on Cracked.com, 5 Things You Won't Believe Are Making You Dumber, claims "jet lag gives you permanent memory and learning problems" and cited several studies. But when you look at the cited study, it shows permanent mental deficits in hamsters only a month after they get jet lagged. I'm not sure if this can be construed as permanent damage.

So, do frequent travelers have more memory and learning problems than other people? Numerous academics and world leaders frequently travel and none of them attribute memory/learning problems to their travel (yet), so I'm a bit inclined to treat this with skepticism.

  • 1
    This is only somewhat tangentially related, but a study found that ecstasy users did not have decreased cognitive function due to ecstasy use, but rather due to sleep deprivation and dehydration related to all-night partying. Both of those factors can potentially occur due to long-distance travel. Ecstasy question here. – John Lyon Jun 28 '12 at 23:54
  • 1
    Cracked is a satire magazine. I do not think that satire really counts as a notable claim. – Chad Jun 29 '12 at 16:11
14

It can, but only if it's chronic jet-lag (i.e. You're a long haul flight attendant or pilot, or you make long haul trips regularly).

A paper in Nature Neuroscience, Chronic 'jet lag' produces temporal lobe atrophy and spatial cognitive deficits, came to the following conclusion:

Time-zone travelers encounter a pattern of light and darkness, and their endogenous circadian rhythms adapt to the new external time cue until both timing systems synchronize, but the long-term repeated disturbance of synchronization between the two timing systems impairs physiological and psychological health and induces stress. Salivary cortisol levels in cabin crew after repeated exposure to jet lag were significantly higher than after short distance flights, and the higher cortisol levels were associated with cognitive deficits that were dependent on non-semantic stimuli. The present study demonstrates that significant prolonged cortisol elevations produce reduced temporal lobe volume and deficits in spatial learning and memory; these cognitive deficits became apparent after five years of exposure to high cortisol levels.

(I would be interested in reading the full paper if anyone has a Nature subscription.)

By the same author, Chronic jet lag produces cognitive deficits (PDF) measured the saliva cortisol levels of airline ground staff and cabin crew and found that they were elevated for long-haul flight crews even before they departed:

In the present study, all the aircrew subjects had at least several transmeridian flights in the preceding weeks, which may account for the increased cortisol secretion in the aircrew subjects. This finding is in contrast to earlier reports of no increased cortisol secretion after transmeridian flying (Desir et al., 1981). The study of Desir et al. (1981), however, was conducted in subjects that had no circadian rhythm disruption in the previous year. International transmeridian flying was associated with significantly raised salivary cortisol compared to short-distance flying in the same cabin crew subjects on the outward journey. This indicates that the increase in circulating cortisol was not caused by the effect of flying per se. It is possible, however, that anticipation of the deleterious effects of “jet lag” was stressful for these subjects, and this caused the increase in cortisol secretion before the circadian disruption. This effect was observed across all four career cohorts, which suggests that it is not something to which the subjects were able to adapt. One might have expected that after 4 years of flight experience, the subjects would have adopted a successful strategy for reducing the negative impact of flying.

Recent evidence has shown that chronic exposure to high levels of circulating corticosteroids impairs cognitive function in both animals and humans (Lupien et al., 1994, 1997, 1998; McEwen and Sapolsky, 1995). After 4 years of transmeridian flying expe- rience, the aircrew showed statistically significant correct key rate and reaction time deficits. The delayed onset of this decrement implies that exposure to the elevated level of cortisol for 4 years had impaired these functions a result, which is in line with previous findings (Lupien et al., 1994, 1997; McEwen and Sapol- sky, 1995). Years of career also appeared to negatively affect the ground crew’s cognitive performance as well. This decline may be explained by age-related influences, however, further study is required to confirm this (Grady et al., 1998; Hazlett et al., 1998).

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .