The “owls” and “larks” added DNA
People with different chronotypes, that is, “owls” and “larks”, go to bed at different times. And this is not only a matter of habit – “owl” and “larks” largely depends on genes. The other day, Nature Communications published a large-scale study in which features of chronotypes were compared with genetic data. As a result, we managed to find as many as 351 sections in our DNA, which to some extent affects the chronotype; whereas before it was believed that there are only 24 such sites in our genome. If there are certain sequences of nucleotides in these areas, a person is inclined to wake up earlier.
We are talking about DNA segments, and not specific genes, that is, there may be more than one gene, and even with regulatory sequences. Among the genes that have fallen into these areas of the genome are those that control biological clocks, those that affect glucose metabolism, those that affect the response to nicotine and caffeine, and many more. Some of them work in the brain, some kind of – in the retina, some – in other places.
Along the way, the authors of the work noticed that the “soviet” a person is, the higher his genetic predisposition to depression, anxiety and schizophrenia, and the worse he feels. This is due precisely to the chronotype, but not to insomnia and not to the quality of sleep (although it can be assumed that if a person does not just go to bed late and get up late, but also sleep poorly, then the likelihood of neuropsychiatric disorders will only increase)
At the same time, no connection was found between the “genes of the chronotype” and the likelihood of diabetes or obesity. However, it is necessary to clarify here that it is usually said about diabetes and obesity in connection with sleep, when a person randomly disrupts his daily rhythm, when his body simply cannot understand how to live – “lark” or “owl”. That is, probably, it is necessary to distinguish the chronotype, which went by genes, and the one that we impose on ourselves.