Why Your Genes May Be To Blame For Your Need For Extra Sleep
Since the human genome was mapped in 2000, genetic causes for all sorts of things have been found. One of these is a genetic variation that means that some people find it harder to get out of bed in a morning than others. They need at least an extra thirty minutes in bed than others. Of course, in these dark winter months most people would probably say they could do with an extra half an hour in bed, but most of them will be just trying it on.
The genuine cases, who really do need more sleep, have a variation on gene ABCC9. The variation is found in as many as one in five Europeans.
Researchers from Ludwig Maximilians University and Edinburgh University studied around 10,000 Europeans from various member states, and questioned them about how many hours’ sleep they got each night (on nights when they didn’t have something in particular to get up for the next day). They then took samples of their blood and analysed their DNA.
Those with the variation on ABCC9 needed more than the average, which is eight hours’ sleep per night.
A possible reason for the effect of the variation is that the normal function of gene ABCC9 is to detect energy levels in the body. Perhaps in the variation of the gene, it detects too little energy and makes the body want to sleep more to recover.
One of the researchers, Dr Jim Wilson from the University of Edinburgh’s Centre for Population Health Sciences said: “Humans sleep for approximately one-third of their lifetime. A tendency to sleep for longer or shorter periods often runs in families despite the fact that the amount of sleep people need can be influenced by age, latitude, season and circadian rhythms. These insights into the biology of sleep will be important in unravelling the health effects of sleep behaviour.”
