What's the Magic Number for Sleep?
Consistently sleeping 7 hours per night was associated with optimal cognitive function and mental health for middle-aged adults, a new study found. Sleep disturbances are common in older age, and previous studies have shown associations between too much or too little sleep and increased risk of cognitive decline, but the ideal amount of sleep for preserving mental health has not been well described, according to the authors of the new paper. In the study published in Nature Aging, the team of researchers from China and the United Kingdom reviewed data from the UK Biobank, a national database of individuals in the United Kingdom that includes cognitive assessments, mental health questionnaires, and brain imaging data, as well as genetic information.
@aronyak The researchers also reviewed brain imaging data and genetic data from 39,692 participants in 2014 to examine the relationships between sleep duration and brain structure and between sleep duration and genetic risk. In addition, 156,884 participants completed an online follow-up mental health questionnaire in 2016-2017 to assess the longitudinal impact of sleep on mental health. Both excessive and insufficient sleep was associated with impaired cognitive performance, evidenced by the U-shaped curve found by the researchers in their data analysis, which used quadratic associations.