Research suggests that 7 hours is an ideal sleep duration for middle-aged and elderly individuals, with inadequate or excessive sleeping contributing to reduced mental health and cognitive performance.
Sleep plays an essential role in cognitive and psychological wellbeing, as well as keeping waste products out of our brains. Our sleep patterns change with age; difficulties sleeping may arise in terms of difficulty falling or staying asleep and decreased quality/quantity sleep – believed to contribute to psychiatric disorders and cognitive decline among elders.
Data was collected and analyzed from nearly 500,000 participants aged 38-73 between 1998 and 2009. Each individual was asked questions regarding their mental health, well-being, sleeping patterns and cognitive ability, in addition to participating in cognitive tests. There was also existing genetic and brain imaging data for approximately 40% of these individuals participating.
Through data analysis, it was discovered that both insufficient and excessive sleep contributed to decreased cognitive performance – including problem-solving skills, memory, visual attention and processing speed. Sleeping for seven hours every night proved ideal for optimal cognitive health as well as psychological well-being with individuals experiencing more depression/anxiety symptoms as well as poorer overall well-being if their rest period were longer or shorter than 7 hours per night.
One reason for the correlation between inadequate sleep and cognitive decline may be disruptions to slow-wave deep sleep, and memory consolidation and amyloid build-up, two key proteins implicated in dementia. Poor rest can also limit our brains ability to eliminate toxins.
Researchers discovered a correlation between sleep duration and changes to brain area structures associated with memory and cognitive processing – specifically memory – and greater changes due to sleeping longer than 7 hours or shorter than 7 hours respectively.
Accumulating seven hours of uninterrupted, restorative sleep each night was crucial to both mental health and well-being, and cognitive performance. Prior research also indicated that interrupted sleeping patterns may increase inflammation levels – potentially increasing susceptibility for age-related diseases in elderly individuals.
Though researchers could not definitively establish that either inadequate or excessive sleep caused cognitive issues, their analysis examining people over an extended time frame suggests this theory. Unfortunately for older individuals however, their poorer sleeping may be complicated by genetic makeup and brain structure combinations influencing how well they sleep.
Researchers say their results demonstrate that too little or too much sleep may be a major risk factor for cognitive decline among seniors as they age, supported by studies showing an association between sleep duration and risk of dementia or Alzheimer’s disease, both of which feature cognitive decline as one of their symptoms.
