Sleep, brain function linked in another study

Another study confirms the importance of sleep as it relates to cognition in older adults. Just how sleep affects brain function, however, depends on age, according to the researchers.

Some seniors have worse memory and executive function when they have problems getting high-quality sleep or when they sleep too much or too little, according to a study out of the University of Warwick published in PLOS ONE. The authors reached their conclusions after analyzing sleep and cognitive data from 3,968 men and 4,821 women who took part in the English Longitudinal Study of Aging. Respondents reported on the quality and quantity of sleep over one month.

In adults aged 50 to 64 years, those who slept fewer than six or more than eight hours a night had lower brain function scores. By contrast, in adults aged 65 to 89 years, lower brain function scores were observed only in those who slept more than eight hours.

“Six to eight hours of sleep per night is particularly important for optimum brain function in younger adults,” says Michelle A. Miller, PhD. “These results are consistent with our previous research, which showed that six to eight hours of sleep per night was optimal for physical health, including lowest risk of developing obesity, hypertension, diabetes, heart disease and stroke.”

In the adults aged 50 to 64, sleep quality was not significantly associated with brain function scores, whereas in the adults older than 65, a significant relationship existed between sleep quality and the observed scores.

“Sleep is important for good health and mental wellbeing,” says Francesco Cappuccio, MD, DSc. “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.”

Miller adds: “If poor sleep is causative of future cognitive decline, [then] 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.”

Last month, researchers at the University of Oregon also published research linking sleep and cognition in older adults.

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