1 vol., 272 p. Lowe C.R. Dean P.D.G. Affinity chromatography £ 6,25 1975 John Wiley and Sons Chichester London

Abstract

International travel is inescapable for millions of people. The general travel fatigue associated with any international flight is quickly overcome, whereas jet lag is longer lasting. Jet lag symptoms diminish in parallel with the adjustment of circadian rhythms, although this relationship between adjustment of the body clock and amelioration in jet lag symptoms is not so strong in some individuals. There are two validated questionnaires for the measurement of jet lag symptoms, which include insomnia, daytime sleepiness, diminished performance, and disturbances in mood and gastrointestinal function. The severity of the symptoms depends on the duration and direction of flight, flight schedule, time of day in destination, and individual differences. Knowledge of the human circadian system can be used to develop interventions that may accelerate adjustment of circadian rhythms and recovery from jet lag. In particular, careful timing of outdoor or bright light exposure, meals, and exercise may be helpful, although there is still not enough evidence that these interventions work for all individuals. Melatonin has been found to reduce symptoms of jet lag, although daytime ingestion of this substance should be considered carefully, as it can induce drowsiness and can impair human performance. It is unclear whether melatonin is best used as a synchronizer of the body clock or as a hypnotic to improve sleep quality. Conventional hypnotics may improve sleep but could have hangover effects on daytime functioning. There is little evidence that age, gender, diet, or caffeine moderates jet lag symptoms. Individuals can be assessed for ‘chronotype’ (morningness/eveningness) or individual circadian phase (by measuring the circadian rhythm of core body temperature or salivary melatonin concentration), although how these differences translate to differences in treatment is unclear at present.