Matthew Walker on health: what the evidence says · JRE #1109
SUBJECT: HEALTH
The short answer
Walker claims a study found that one week of 6 hours of sleep per night distorted the activity of 711 genes compared to getting 8 hours. Walker's figure references a 2013 study by Moller-Levet and colleagues, published in the Proceedings of the National Academy of Sciences, which tracked 26 participants through one week of sleep restriction (about 5.7 hours per night) and one week of sufficient sleep (about 8.5 hours per night).
Not a true/false call. Every claim is logged with its sources; read the exhibits below.
The first was that a sizeable 711 genes were distorted in their activity caused by one week of six hours of sleep.
What the evidence says 01 / RECORD
Walker's figure references a 2013 study by Moller-Levet and colleagues, published in the Proceedings of the National Academy of Sciences, which tracked 26 participants through one week of sleep restriction (about 5.7 hours per night) and one week of sufficient sleep (about 8.5 hours per night). Blood transcriptome analysis found that 711 genes were significantly up- or down-regulated after the week of insufficient sleep compared to the week of sufficient sleep, matching the number Walker cites. The affected genes were linked to circadian rhythm regulation, immune and inflammatory responses, oxidative stress, and metabolism. The study has not been retracted and has been cited in hundreds of subsequent papers. Its main limitation is a small sample size (n=26) typical of intensive laboratory sleep studies, which affects how broadly the specific gene list generalizes but does not undermine the reported topline number.