Sleep problems may be linked to worse memory and executive function in older people, according to a recent study.

Researchers from the University of Warwick in the United Kingdom found that there is an association between both quality and duration of sleep and brain function which changes with age.

"Sleep is important for good health and mental wellbeing" researcher Francesco Cappuccio said in a statement. "Optimizing 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."

For the study, researchers analyzed sleep and cognitive data from 3,968 men and 4,821 women who took part in the English Longitudinal Study of Ageing. Respondents reported on the quality and quantity of sleep over the period of a month.

Researchers found that in adults aged between 50 and 64 years of age, short sleep and long sleep were associated with lower brain function scores. By contrast, in older adults (65-89 years) lower brain function scores were only observed in long sleepers.

Short sleep was defined as sleeping for less than six hours and long sleep as at least eight hours.

"[Six to eight] hours of sleep per night is particularly important for optimum brain function, in younger adults," researcher Michelle Miller said in a statement. "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".

Researchers found that in the younger pre-retirement aged adults, sleep quality did not have any significant association with brain function scores, whereas in the people at least 65 years of age, there was a significant relationship between sleep quality and the observed scores.

Miller said this study could lead to non-pharmacological improvements in sleep which may provide an alternative low-cost and more accessible Public Health intervention, to delay or slow the rate of cognitive decline."

The findings were recently published in PLOS ONE.