If you are one of those people who drops off instantly into a deep sleep every night, then the chances are you inherited the ability from your parents. For those who toss and turn there is no hope: good sleep is encoded in the genes, say researchers.
Hans-Peter Landolt and his team at the University of Zurich compared the sleep patterns and DNA of two groups.
The first contained people who find that caffeine disrupts their sleep. The second group falls asleep easily, even after a strong black coffee late at night.
The difference in sensitivity to caffeine is thought to be related to our ability to process an energy-rich compound, adenosine. ”Caffeine is an antagonist for adenosine sensors, blocking the binding sites and preventing people from feeling sleepy,” said Landolt.
By analysing DNA, Landolt showed that caffeine-insensitive people have a genetic mutation that appears to make the adenosine enzyme less active. ”It seems that when this enzyme is inhibited, people have more deep and intense sleep,” he said.
According to Landolt, about 10% of people have inherited the genetic variation from one of their parents.
The finding, which appears in the Proceedings of the National Academy of Sciences, could help people who have trouble sleeping. ”For certain sleep disorders such as insomnia it may be possible to manipulate the adenosine system and inhibit the enzyme to enable people to have more deep and intense sleep,” he said. — Â