Dangers in overwinding our biological clocks

The 24-hour society is shortening lives because of the havoc it plays with our biological clock, scientists claim.

One in five workers in urban societies is now working outside normal office hours in response to the increased demand from consumers for round-the-clock shopping, banking and other services.

But convenience for customers comes at a price paid in terms of increased sleep disruption, gastro-intestinal disorders and risk of heart disease among those who work unsocial hours.

Researchers at the Centre for Chronobiology at the University of Surrey warn in The Lancet that the increased health risks will lead to more litigation unless employers use current scientific knowledge about how to help employees adapt their circadian rhythms.





Pressure on employers to reduce increased risks from heart disease and other health problems are likely to increase, they say.

Carefully timed exposure to light, which may include the use of dark goggles for night workers during the day, and selective use of the hormone melatonin can speed adaptation to new hours of work. But the authors warn that there is "no information on the long-term safety" of melatonin.

The body's clock maintains circadian rhythms in temperature, blood pressure, sleep and wakefulness, mental performance and the synthesis of certain hormones.

Trying to sleep at the "wrong" phase will usually lead to a disturbed "night" with frequent awakenings.

The result is the exhaustion seen in shift workers and people affected by jet lag.

- INDEPENDENT