Better Living Through Psychology

According to University of Massachusetts mathematicians Tanya Leise and Hava Siegelmann, jet lag happens because different systems in the body have different circadian rhythms. For example, cells in your digestive system prepare for digestion at particular times of the day. Secretion of the sleep hormone melatonin is higher at night and lower during the day. Fortunately we are equipped with a ‘master clock’ - a brain structure called the suprachiasmatic nucleus (SCN) - which effectively keeps things synchronized.

Leise and Siegelmann suggest that when the ‘local clocks’ are disrupted, say by travelling to a different timezone, the SCN can take some time to adjust. How long this adjustment takes depends on a variety of factors, such as the strength of the connection between the SCN and the ‘local clocks’, and of course the rhythm of those clocks.

To find out how this hierarchical system works, Leise and Siegelmann developed a model that incorporates data on circadian rhythms, on the factors that cause them to change and adapt and on how they respond to ‘commands’ from the SCN. Simulations the researchers ran showed the system gets most disrupted when the ‘master clock’ is shifted forward by 5 to 8 hours. The reason this disruption happens is that as the master clock adjusts by shifting in one ‘direction’, for example jumping forward to six or seven hours ahead, other ‘local clocks’ have tried to adjust by going backwards or delaying, by say 18 or 17 hours.

HOW CAN I USE IT?

• Make time zone adjustments gradual whenever you can. Ideally, travel across four hours of time zones, have a one or two day layover and then continue.
• Of course on longer flights that suggestion won’t be possible, so try this: