Little or disturbed sleep can lead to poor memory and cognitive functions during old age, a new study suggests.
The study conducted by researchers at the University of Warwick found that old people with low-quality sleep scored low on cognitive tests than other people who had good quality of sleep for optimal duration.
Data for the study came from 3,968 men and 4,821 women, who enrolled in the English Longitudinal Study of Ageing (ELSA).
Researchers didn't find any link between brain function scores and sleep quality in pre-retirement age participants. However, little or poor quality sleep was strongly associated with memory problems and other brain functions in older people.
"Sleep is important for good health and mental wellbeing" said Professor Francesco Cappuccio, "Optimising sleep at an older age may help to delay the decline in brain function seen with age, or indeed may slow or prevent the rapid decline that leads to dementia."
Researchers found that people who were between 50-64 years of age, short sleep (<6hrs per night) as well as long sleep (>8hrs per night) were associated with poor cognitive abilities.
"Six-eight hours of sleep per night is particularly important for optimum brain function, in younger adults. These results are consistent with our previous research, which showed that 6-8 hours of sleep per night was optimal for physical health, including lowest risk of developing obesity, hypertension, diabetes, heart disease and stroke," Dr Michelle A Miller said, according to a news release.
The study is published in the journal PLOS One and is supported by Economic and Social Research Council (ESRC).
Related studies have shown that poor quality sleep don't just make people cranky, but also accelerate brain ageing, increasing risk of Alzheimer's disease.