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19 October, 2007

Health Tips-11: "How to beat the Clock inside you - The Independent"

Deep in your brain, lodged just behind your eyes, there is a literal body clock. All humans have one: the clock is called suprachiasmatic nucleus, and scientists can isolate it, plug it up to electrodes, and convert the ticking into a regular, electronic beep. The clock can govern anything subject to our 24-hour routine: body temperature, hormone cycle, patterns of alertness and tiredness. Because it influences the day-by-day, it has a knock-on effect for the longer term, probably prompting the body's menstruation and reproductive cycles and helping our adjustment to seasonal changes.

The trouble, researchers are now warning, is that this sensitive piece of biological timekeeping is being skewed by our unnatural lifestyles. International travel across different time zones, more shift work and late-night leisure pursuits take no heed of that little nucleus. Increasingly the body clock is being masked by caffeine or amphetamines or simply ignored.

"I think we should be very concerned about our 24-hour society," says Jo Arendt, Professor of Endocrinology, University of Surrey. Her conclusion is that if you mess with your natural tick-tock, you may be inviting trouble... How do scientists suggest you can best adapt your body? The main cue for the clock, the factor which adjusts it to 24 hours - its natural cycle is actually 24 hours and 20 minutes - is light. (Our 'clock' is particularly close to the retina, which is why blind people, their natural timekeeping unprompted by daylight, have a much higher incidence of sleeping disorders.) So the best way to adapt your body to unusual hours is by providing it with an intensity of light which might otherwise be absent. NASA, for instance, uses strong light to shift its astronauts.

Another, closely related way of adapting the clock is using melatonin. It is a naturally occurring "chrono-biotic"; a hormone-like secretion from the pineal gland, melatonin's basic function is to tell your body "when the dark happens". It also reduces the length of night to determine reproduction or sleep cycles.

Courtesy: The Independent.
Grateful thanks to The Independent.

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