When you reach middle age and older, sleeping too much or too little can have a demonstrable effect on cognitive performance and mental health. So what is the ideal amount of sleep?
As you age, many people experience changes in their sleep patterns, including difficulty falling asleep and staying asleep, and decreased quantity and quality of sleep.
Because sleep is such an important part of how you feel while awake, any disruption to your body’s natural rhythm can have serious effects.
Sleep especially impacts cognitive performance. Sleep too little and you’ll find it hard to concentrate, have impaired judgement and be in a bad mood. But sleep too much, and you will experience similar effects.
Almost a quarter of Australians report having sleep problems, with that number rising to around 34 per cent once people reach age 55.
These effects become even more pronounced as you enter middle age. So what is the ideal amount of sleep for older people?
The answer, it turns out, is seven hours.
In a paper published in the journal Nature Aging, researchers from the UK and China examined data from nearly 500,000 adults aged 38 to 73 years from the UK Biobank.
Participants were asked about their sleeping patterns, mental health and wellbeing, and took part in a series of cognitive tests. Brain imaging and genetic data were available for almost 40,000 of the study participants.
The researchers found that both insufficient and excessive sleep were associated with impaired cognitive performance, such as processing speed, visual attention, memory and problem-solving skills.
They also found higher incidences of anxiety and depression and poorer overall wellbeing if participants regularly slept for more or less than seven hours.
Keeping your sleep consistent was also found to be important for older people. Interrupted sleep patterns are often associated with inflammation in the brain, which can indicate a susceptibility to age-related neurological disorders.
“Getting a good night’s sleep is important at all stages of life, but particularly as we age,” says Professor Barbara Sahakian, co-author of the study.
“Finding ways to improve sleep for older people could be crucial to helping them maintain good mental health and wellbeing and avoiding cognitive decline, particularly for patients with psychiatric disorders and dementias.”
As to exactly why sleep tends to become more disrupted as we age, and why it seems to affect some people more than others, the researchers say the answers still aren’t clear.
“The reasons why older people have poorer sleep appear to be complex, influenced by a combination of our genetic makeup and the structure of our brains,” says Professor Jianfeng Feng, another co-author of the research.
If you enjoy our content, don’t keep it to yourself. Share our free eNews with your friends and encourage them to sign up.