Gaby
A new study upends the assumption that the youngest and oldest people sleep the least.
But the study found people actually sleep the least in middle age. Sleep duration falls through early adulthood until about age 33, then begins rising again after roughly 53.
To investigate how sleep patterns change across a lifetime and across cultures, scientists analyzed data from 730,187 participants aged 19 to 70 in 63 countries.
In the prime of life, there’s little time for sleep
The study involved researchers from the University of Lyon (France), University College London, the University of East Anglia, the University of Leeds, Bournemouth University, and Lancaster University (UK).
The primary focus of the research was to identify signs of dementia. Volunteers played a mobile game called Sea Hero Quest, designed for neuroscience research, and answered questions in a survey. Some of those questions specifically asked about sleep duration at different life stages.
The data showed the youngest participants slept the longest, according to The Independent. Sleep duration gradually decreases until about age 33, stays roughly steady until 53, and then starts to increase again. The authors suggest the shorter sleep in middle age is likely linked to the demands of raising children and advancing in a career.
Women sleep longer than men, but only by a few minutes
Overall, volunteers averaged 7.01 hours of sleep per night. Sleep duration varied by gender, region, and education level.
The data held another surprise: women slept, on average, 7.5 minutes longer than men.
People in the United Kingdom slept slightly less than the global average. Residents of countries closer to the equator slept even fewer hours.
In Eastern European countries such as Albania, Slovakia, Romania, and the Czech Republic, people slept 20 to 40 minutes more than the average.
The study’s conclusions were published in the journal Nature Communications. The findings on sleep duration allowed the authors to redefine stages of adult life as early adulthood (19–33 years), middle adulthood (34–53 years), and late adulthood (54+ years).
Other research teams have previously suggested that regular nightly sleep should last at least 7 hours. Young people and those with chronic illnesses need to sleep at least 9 hours.
Sleeping less than 7 hours increases the risk of cardiovascular disease, diabetes, and hypertension. It also raises the chance of depression and obesity and disrupts immune-system function.
