Sleeping little and not feeling tired ?

For a long time, scientists couldn’t explain why, while for the majority of us 7 to 8 hours of sleep are necessary, some people can sleep 5 to 6 hours or even less and wake up feeling energized and ready to tackle the day. Several clues have been studied in recent years, and as it’s not uncommon for this ability that we all envy to run in families, everything suggests that the answer to this mystery lies in our genes.

Genetics of short sleepers ?

That’s what researchers at the University of California, San Francisco thought in 2009 when they noticed a peculiarity in a family known to one of the researchers. All members of this family need a minimum of 8 hours of sleep, except for the mother and daughter, who are operational for the whole day after 6 hours for one and 6.5 hours for the other.

The researchers then studied the genetics of this family and discovered that these women carried a mutation on a gene whose expression, under normal circumstances, inhibits the expression of other genes involved in regulating our circadian rhythm. This would confirm the hypothesis that something is happening at the genetic level. And after inducing a mutation on the same gene in mice, the observation was the same as in this family: some were awake longer and needed less recovery time.

More recently, other mutations have been identified on other genes, and each time, it seems that these particularities always have an influence on genes regulating the internal clock.

However, there have been new developments since the summer of 2019. This time, the mutation involves the gene encoding the β1-adrenergic receptor, which, when activated, induces a state of alertness. In carriers of this mutation, the receptor would be much more active than in the rest of the population, which would explain why those affected are vigilant for longer periods, and even more quickly, without showing signs of fatigue.

However, it should be noted that genetic mutations do not only result in short sleeper profiles. Other mutations can also explain certain night owl profiles or the need for a longer sleep period in long sleepers… So, it is up to each individual to take the time to identify their own needs and do their best to meet them.

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884988/

2. https://www.cell.com/neuron/fulltext/S0896-6273(19)30652-X 

3. https://www.cell.com/cell/fulltext/S0092-8674(17)30346-X

4. https://www.nature.com/articles/mp2011142