Ben Franklin may have had it partly right with his belief that "early to rise" makes one "healthy, wealthy and wise." Natural early risers may experience greater overall well-being and better mental health compared with night owls, a new study suggests.
But what Franklin likely didn't know is that your chronotype, or tendency to sleep and rise at a particular time, is heavily dependent on your genes — and there might not be much you can do to change it.
In the new study, published today (Jan. 29) in the journal Nature Communications, researchers identified 351 regions in the human genome associated with being an early bird, only 24 of which were known previously. Those people in the study with the most gene variants associated with early rising tended to go to sleep upward of a half hour sooner than others with fewer of these variants. [5 Surprising Sleep Discoveries]
What's more, the study found that these genomic regions were linked to the body's circadian clock and to the retina, supporting the theory that the brain's ability to detect light through the retina sets the body's clock to a 24-hour cycle of sleep and wakefulness.
"Part of the reason why some people are up with the lark while others are night owls is because of differences in both the way our brains react to external light signals and the normal functioning of our internal clocks," lead study author Samuel Jones, a research fellow studying the genetics of sleeping patterns at the University of Exeter Medical School in the U.K, said in a press statement.
The study tapped into genomic data from nearly 700,000 participants in a U.K.-based nonprofit health project called the U.K. Biobank and the U.S.-based private genome analysis company 23andMe. The 23andMe participants were asked via a health survey whether they were a "morning person" or a "night owl," or somewhere in between.
As such an answer could be subjective, the researchers validated their findings with information from wristband activity trackers worn by more than 85,000 individuals in the UK Biobank project, which revealed with no bias when they went to sleep and woke up.
The researchers found differences in sleep timing but not sleep quality. They also found no increased risk of obesity and diabetes among night owls, contrary to some earlier studies. But they uncovered an apparent causal link between being a night owl and being more prone to depression, anxiety and schizophrenia.
That is, through their statistical analysis, the researchers showed that the more of a night owl someone is, as defined by their genetics, the greater their risk of schizophrenia and the lower their wellbeing. This was not dependent on factors such as poor sleep quality or lack of sleep, they found.
The reason for this link between sleep timing and poor mental health remains unknown but perhaps is due to a combination of factors, said co-lead study author Jacqueline Lane, an instructor and researcher at the Massachusetts General Hospital Center for Genomic Medicine. These factors could include unknown protections offered by the genes in early risers, or the physical stimulation of morning light that early risers receive, or societal advantages of feeling awake in the morning and midday in a culture dominated by a 9-to-5 work cycle, Lane said. [The Science of Jet Lag: 5 Surprising Findings]
"Our current study really highlights the need for further study of how chronotype is causally linked to mental health and, until these studies are done, we can only speculate on the mechanism," Lane told Live Science.
If you are a bona fide night owl who needs to function in an early-riser world, you aren't entirely out of luck, said Nancy Rothstein, a sleep consultant known as The Sleep Ambassador with a focus on business productivity.
Rothstein said you can better prepare for sleep by not consuming caffeine in the afternoon and by tuning out of technology at least an hour before going to bed, so that sweet sleep can arrive soon after you hit the pillow.
"Asking yourself to get to bed a few hours earlier is not always realistic," Rothstein told Live Science. "Your body clock needs to adapt to the change in timing. Fill the hour [before bed] with a shower, reading with a dim light, having a conversation, or doing some gentle stretching," Rothstein said. "Practice a simple mindfulness technique that gets you out of your head and into your breathing and body awareness."
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Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science
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