The human body clock is the curse of any shift worker or traveler arriving in a new time zone. Although one's body clock can be adjusted by external cues, such as light – a factor that devices such as the Re-Timer and Litebook are designed take advantage of – the adjustment period can vary significantly for different people. Now researchers have discovered the mechanism that controls how easily such adjustments can be made.

Body, or circadian, clocks orchestrate daily rhythms in our physiology. When this internal clock is thrown out of sync, be it by working nights or taking an international flight, it can negatively affect our sleeping patterns and metabolism.

"We are not genetically pre-disposed to quickly adapt to shift-work or long-haul flights, and as so our bodies' clocks are built to resist such rapid changes," says Dr David Bechtold. "Unfortunately, we must deal with these issues today, and there is very clear evidence that disruption of our body clocks has real and negative consequences for our health."

Dr Bechtold led a University of Manchester team that worked with scientists from Pfizer on a series of experiments involving mice that focused on an enzyme known as casein kinase 1epsilon (CK1epsilon), which is a component of the body clock.

"At the heart of these clocks are a complex set of molecules whose interaction provides robust and precise 24 hour timing," says Dr Bechtold. "Importantly, our clocks are kept in synchrony with the environment by being responsive to light and dark information."

The team found that mice lacking in CK1epsilon were able to adapt to a new light-dark environment much faster than normal. The team followed up this finding by showing that drugs that inhibited CK1epsilon were able to speed up the adaption rate of normal mice. Importantly, faster adoption to the new environment reduced metabolic disturbances caused by the time shift.

"As this work progresses in clinical terms, we may be able to enhance the clock's ability to deal with shift work, and importantly understand how maladaptation of the clock contributes to diseases such as diabetes and chronic inflammation," says Dr Bechtold.

The team's discovery is published in the journal Current Biology.