With travel opening up again, flying is back on the agenda – which can also mean jetlag. Dr Jane Wilson-Howarth reaquaints herself with a perennial problem and explains how to avoid it
Jetlag is the constellation of symptoms experienced when travelling rapidly to other time zones. The body’s internal clock runs on a day that is longer than 24 hours but is synchronised with earth’s 24-hour day by sunshine. Travel disturbs this balance, and subtle changes in the body’s metabolism are detectable even on moving only two or three time zones. This has been measured in elite athletes.
Jetlag can cause fatigue, brainfog, difficulty concentrating and more (Shutterstock)
Jetlag causes an array of symptoms, including:
• Fatigue
• Temporary brain fog
• Difficulties concentrating and staying alert
• Feeling generally unwell
• Low mood
• Disturbed sleep
• Stomach problems – constipation or diarrhoea (bowels take longer to adjust than brains).
The more time zones that are crossed, the worse symptoms are likely to be. Many feel that it’s more disruptive travelling east than west. Adjustment takes about one day per time zone crossed. If you set out in a stressed, tired state the symptoms will be worse. Long pre-departure to-do lists are the enemy of sleep and good adjustment. Long-flight fatigue, dehydration (common on long flights) and alcohol make things worse; caffeine should be avoided after midday.
Light hitting the retina of the eye signals the hypothalamus to tell the pineal gland in the brain to reduce the production of melatonin – the hormone that produces restful sleep, and which can be taken as a supplement. Keeping busy so you don’t fall asleep before the locals is worth striving for.
Exposure to natural light in the afternoon and evening will help westward travellers reset to later time zones; getting out into the morning sunshine will help eastward travellers adjust to earlier time zones – this is unless you’ve travelled more than eight time zones, in which case the eye and brain may misinterpret early morning light for dusk.
Long-haul easterly travellers should consider wearing sunglasses and avoid bright sunshine in the morning but allow plenty of sun exposure in the late afternoon for the first several days. Westward travellers should avoid the sun for the few hours before dark. Obviously care needs to be taken to avoid sunburn, and travellers should aim to make gradual shifts to daily routines including to meals. Some travellers find apps help with this process.
Protein-rich breakfast helps jetlag (Shutterstock)
There is some evidence that manipulation of the diet may also help alleviate jetlag, notably:
• Protein-rich meals in the morning
• Lots of carbohydrates in the evening
• Amino acid supplements – tyrosine and tryptophan, which are both available from herbalists and pharmacies – have been suggested
• Homoeopathic arnica and No-Jet-Lag help some travellers
• Exercise before and after the journey is also a good idea.
Melatonin is available online and from pharmacies at some destinations; 0.5mg is enough to do the trick. Melatonin exists in sour cherries but you’d need to eat about 50kg of them to adsorb a single dose. Drinking tart cherry juice concentrate is a better option. After flying east take it 30 minutes before planning to sleep; if it is needed after flying west, it is probably best taken in the morning.
Try to sleep on the plane if it is nighttime at your final destination. One-off use of sleeping pills can help with this. Most sleeping pills are designed to last for eight hours while diazepam lasts four hours in the body and is sometimes prescribed for aviophobia (fear of flying). Drowsiness-inducing antihistamines such as Phenergan can also be usefully sedating.
Jetlag varies between travellers but the most important piece of advice is to take your time and enjoy slowing down, then your symptoms will be minimal.
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