Researchers from the University of Cambridge and Fudan University have stated that 7 hours is the ideal amount of sleep for people in middle age and beyond to avoid cognitive decline and mental health issues. Sleep plays a crucial role in enabling cognitive function and maintaining good mental health. It also helps in preserving brain health by removing waste from cells.
According to research published in the journal "PLOS," our sleep patterns change with age, including difficulties in falling asleep, staying asleep, a decrease in total sleep time, and the depth of sleep. These disturbances are believed to contribute to cognitive decline and psychological disorders in older adults.
Researchers from the UK and China examined health data from half a million individuals aged 38 to 78 from the UK Biobank. The data included surveys about their sleep patterns, mental health, and well-being, and participants engaged in a series of cognitive tests. It also included brain imaging and genetic information for 40,000 of them.
The research team found that both insufficient and excessive sleep were linked to impaired cognitive performance, such as processing speed, visual attention, memory, and problem-solving skills. It was determined that 7 hours of sleep each night is optimal for brain function and good mental health, with individuals reporting anxiety and depression symptoms and generally poorer health if they reported sleeping for longer or shorter durations.
To explain this relationship, the researchers suggested that disruption of slow-wave or "deep" sleep may affect memory strength, while lack of sleep may hinder the brain's ability to eliminate toxins and waste.
