The link between cognitive decline and sleep

A study published in The Lancet Healthy Longevity looked at cognitive function over 10 years in 8,958 people aged 50 and over in England. The research team investigated how different combinations of sleep and physical activity habits might affect people’s cognitive function over time. 

They found that people who were more physically active but had short sleep – less than six hours on average – had faster cognitive decline overall, meaning that after 10 years their cognitive function was equivalent to peers who did less physical activity.

The study found, in line with previous research, that sleeping between six and eight hours per night and higher levels of physical activity were linked to better cognitive function. 

Those who were more physically active also had better cognitive function regardless of how long they slept at the start of the study. This changed over the 10-year period, with more physically active short sleepers (less than six hours) experiencing more rapid cognitive decline.

This rapid decline was true for those in their 50s and 60s in this group, but for older participants (aged 70 and over) the cognitive benefits of exercise appeared to be maintained, despite short sleep.

You can read the full study here:-

https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(23)00083-1/fulltext