Lack of quality sleep affects memory and executive functions in older people, a new research at the University of Warwick shows.
For the study, the U.K. researchers examined sleep and cognitive function data from 3,968 men and 4,821 women who took part in the English Longitudinal Study of Aging. The participants were told to report on the number of hours and quality of sleep over a period of one month.
The study analysis showed that quality and duration of sleep affects brain function. The impact changes with age.
Researchers found that short sleep (<6hrs per night) and long sleep (>8hrs per night) in adults aged between 50 and 64 years of age were linked to lower brain function scores. However, the lower brain function scores were only seen in older adults, aged between 65-89 years, who slept for longer duration.
"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," said Dr Michelle A Miller in a press release.
The team noted that in the younger (pre-retirement aged) adults, sleep quality did not have any major association with brain function scores. On the other hand, in older adults (>65 years), there was a significant relationship between sleep quality and the observed scores.
"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".
"If poor sleep is causative of future cognitive decline, non-pharmacological improvements in sleep may provide an alternative low-cost and more accessible Public Health intervention, to delay or slow the rate of cognitive decline," concluded Dr Miller.
The research was published in the journal PLOS ONE.
