To Nap or Not to Nap?

Recently, my interest was piqued by a British study suggesting that habitual daytime napping is associated with larger total brain volume, a fundamental indicator of brain health. All of us lose brain cells as we get older, and brain volume begins to shrink in our 30s and 40s, with the rate increasing after age 60. Our brain’s physical changes will also alter our cognitive abilities.¹

Should we take a 15- or 20-minute nap after lunch? The midday “riposo” of Mediterranean countries provides an escape from the afternoon heat and a chance for a restorative nap. There are several examples of highly accomplished people who frequently took naps. Winston Churchill was an avid napper who extolled the benefits of “blessed oblivion.” General Douglas MacArthur took a nap every afternoon, as did John F. Kennedy, and top-ranked tennis pro Novak Djokovic makes short naps part of his sleep, meditation, and training regimen.

The British researchers at University College London analyzed data from the UK Biobank and “found that individuals predisposed to napping had a larger brain volume equivalent to being 2.6 to 6.5 years “younger” than non-nappers.”²  Based on self-reported daytime napping, 57% of the cohort reported that they never or rarely took a daytime nap, 38% said they sometimes took a nap, and 5% stated that they usually had a nap during the day.

Researchers used a methodology known as Mendelian randomization (based on the analysis of genetic markers) and found an association. However, the study does not prove definitively that napping causes larger brain volume (italics mine). In addition, all participants were of white British ancestry; results may differ in other populations.

“Our findings suggest a modest causal association between habitual daytime napping and larger total brain volume. Future studies could focus on the associations between napping and other cognitive or brain outcomes.”³ Researchers did not find a correlation between napping and hippocampal volume (which plays a significant role in learning and memory) or between daytime naps and improved cognitive function (e.g., reaction time and visual memory). Still, they observed a genetic predisposition for daytime napping correlated with a larger total brain volume associated with a lower risk of damage from disease and conditions like dementia.⁴

For many, daytime napping is inhibited by a job that requires them to be awake and alert, unless one can find a quiet corner or a “nap pod” suitable for dozing or refreshing meditation. Doing so may boost your performance and possibly prevent “shrinking.”

1. publichealth.columbia.edu/news/changes-occur-aging-brain-what-happens-when-we-get-older
2. sciencedirect.com/science/article/pii/S235272182300089X
3. Ibid
4. neurologyadvisor.com/news/regular-daytime-napping-brain-volume-cognitive-function/