A new study conducted by researchers from University College London, the University of East Anglia, and the University of Lyon has found that people get less sleep during mid-adulthood compared to early and late adulthood. The research, published in Nature Communications, shows that sleep duration decreases during early adulthood until age 33, before increasing again at age 53.
The study, which involved 730,187 participants from 63 countries, uncovered how sleep patterns change throughout the lifespan and how they vary across different countries.
Study participants were playing the Sea Hero Quest mobile game, a citizen science venture designed for neuroscience research, created by Deutsche Telekom in partnership with Alzheimer’s Research UK, UCL, UEA, and game developers Glitchers. Designed to aid Alzheimer’s research by shedding light on differences in spatial navigational abilities, over four million people have played Sea Hero Quest, contributing to numerous studies across the project as a whole.
In addition to completing tasks testing navigational ability, anyone playing the game is asked to answer questions about demographic characteristics as well as other questions that can be useful to neuroscience research, such as on sleep patterns.
The researchers, led by Professor Hugo Spiers (UCL Psychology & Language Sciences) and Dr. Antoine Coutrot (CNRS, University of Lyon) found that across the study sample, people sleep an average of 7.01 hours per night, with women sleeping 7.5 minutes longer than men on average. They found that the youngest participants in the sample (minimum age 19) slept the most, and sleep duration declined throughout people’s 20s and early 30s before plateauing until their early 50s and increasing again. The pattern, including the newly-identified key time points of age 33 when declining sleep plateaus and 53 for sleep to increase again, was the same for men and women, and across countries and education levels.
The researchers say the decline in sleep during mid-life may be due to the demands of childcare and working life.
Professor Spiers said: “Previous studies have found associations between age and sleep duration, but ours is the first large study to identify these three distinct phases across the life course. We found that across the globe, people sleep less during mid-adulthood, but average sleep duration varies between regions and between countries.”
People who report sleeping the most are in Eastern European countries such as Albania, Slovakia, Romania, and the Czech Republic, reporting 20-40 minutes extra sleep per night, and the least in South East Asian countries including the Philippines, Malaysia, and Indonesia. People in the United Kingdom reported sleeping slightly less than the average. People tended to sleep a bit less in countries closer to the equator.
The researchers found that navigational ability was unaffected by sleep duration for most of the sample, except for among older adults (aged 54-70) whose optimal sleep duration was seven hours, although they caution that the findings among older adults might be impacted by underlying health conditions.
Reference: “Reported sleep duration reveals segmentation of the adult life-course into three phases” by A. Coutrot, A. S. Lazar, M. Richards, E. Manley, J. M. Wiener, R. C. Dalton, M. Hornberger and H. J. Spiers, 13 December 2022, Nature Communications.