On October 2, the 108th Nobel Prize in Physiology or Medicine was awarded to a trio of American scientists for their discoveries into the molecular mechanisms that control our circadian rhythms - in other words, our bodies' 24-hour clock.
The experiments conducted by Jeffrey C. Hall, Michael Rosbash and Michael W. Young explained how plants, animals and humans adapt their biological rhythm so that it is synchronized with the periods of day and night. They are the basis for a new understanding of the importance of maintaining regular cycles of sleep and wakefulness, and of the risks we run by allowing those cycles to become disrupted.
Using fruit flies as a model organism, the Nobel laureates isolated a gene that controls the normal daily biological rhythm. We now know that similar biological clocks are ticking inside almost every cell type in our bodies. These clocks regulate critical functions such as behaviour, hormone levels, sleep, body temperature and metabolism. Whenever there is a mismatch between our internal biological clock and the external environment, our wellbeing is affected.
“Virtually everything in our body, from the secretion of hormones to the preparation of digestive enzymes in the gut, to changes in blood pressure, are influenced in major ways by knowing what time of day these things will be needed,” Clifford Saper, a professor of neuroscience at Harvard Medical School, told Britain’s Guardian newspaper. “The most common misconception is that people think that they do not have to follow the rules of biology, and can just eat, drink, sleep, play or work whenever they want.”
The Nobel laureates’ discovery has helped reveal why light continues to exert such a powerful influence on our behaviour and health. It explains why jet-lag feels so awful: your master clock adapts quickly to changing light levels, but the rest of your body is slower to catch up and does so at different speeds. It also explains the extensive health risks incurred by shift workers, who are more likely to suffer from heart disease, dementia, diabetes and some cancers: “They’re having to override their entire biology,” said Professor Russell Foster, chair of circadian neuroscience at Oxford University.
The science of circadian rhythms teaches the importance of maintaining regular habits to keep our internal cellular clocks running on time. Bright lights before bedtime and spending the whole day in a dimly lit office can dampen the natural circadian cycle, leaving us dozy in the morning and too alert to fall asleep promptly at night. “It’s been overlooked for a long time as a real public health problem,” says new Nobel laureate Michael Rosbash. “All of western society is chronically sleep-deprived.” Perhaps it’s time you put your body clock right, and caught up on some of that lost sleep.