A good night’s sleep linked to better memory, especially in the elderly

Many Americans get less than the recommended amount of sleep. Poor sleep has been linked to a variety of chronic diseases like heart disease, obesity and Type 2 diabetes. Now, recent research suggests that poor sleep can also deteriorate memory performance, especially in older adults.

The National Sleep Foundation‘s inaugural Sleep Health Index report that about 35 percent of American adults experience poor sleep quality. Meanwhile, about 20 percent of them say that they do not feel refreshed when waking up at any day of the week.

A study published in the journal Frontiers in Human Neuroscience found that not getting enough sleep and reduced sleep quality affected how older adults remember information about past events. Further, the findings revealed unexpected racial differences in the sleep patterns associated with diminished memory performance across both young and older African American adults.

The researchers suggest that their findings could help pave the way for new research that focuses on the connection between poor sleep and age-related memory decline. The study was believed to be the first of its kind to focus on the relationship between sleep and memory performance with both age and racial differences.

“The night-to-night variability in the older study participants had a major impact on their performance in tests aimed at evaluating episodic memory,” said principal investigator Audrey Duarte. “The association between sleep and memory has been known, but this study’s novelty is showing that the connection is particularly evident for older adults and black participants, regardless of age.”

Poor sleep and memory

Science has firmly established the importance of a good night’s sleep for memory performance. In fact, previous studies have shown that episodic memory – memory for previously experienced events – is dependent on sleep in both young and older adults. For the current study, researchers from Georgia Institute of Technology investigated not only the age-related differences in the effect of sleep quality on episodic memory, but also race-related differences that are largely unexplored by other studies.

The researchers recruited 81 volunteers from the Atalanta area, each carefully screened to eliminate those who had mild cognitive impairment or other confounding factors. The researchers ended up with 50 participants. Duarte and her colleague Emily Hokett looked at certain lifestyle factors to determine how people sleep normally and how their sleeping patterns change over time. They also wanted to know how the participants’ sleep affected their memory performance.

The researchers gave the participants accelerometers on their wrists to keep track of their sleep duration and sleep quality over a testing period of seven nights. While the devices did not have the capability of measuring brain waves, they allowed sleep parameters to be measured even when the participant is in their own home. The researchers wanted to analyze a more realistic measurement rather than one done in a laboratory setting, which normally lasts for a single night.

After the follow-up period, the researchers asked each participant to visit their laboratory and perform a memory test that measured electroencephalography (EEG) brain wave activity, as they try to remember word pairs shown to them earlier in the test. Unsurprisingly, those who experienced better sleep also showed better performances in the test in most of the older adults. However, the researchers were astonished to find that the link between poor sleep and memory-related brain activity also extended to both old and young African American participants.

To further understand the causes behind poor sleep, Duarte and Hokett asked the participants to answer a standardized questionnaire to measure stress levels. They found that most participants do not get the required sleep they need over race-related stress – sleeping about 36 minutes less than most other adults. This loss of sleep equates to a 12 percent decrease in memory-related brain activity.

The researchers hope to expand on their findings by conducting future research with a larger group of participants, especially in underrepresented minorities. However, the main takeaway is that getting regular and quality sleep is important at any age to ensure proper cognitive performance.  (Related: Get a good night’s rest — your immunity and cardiovascular system need it.)

“You can imagine that many people, students among them, may have variable sleep patterns based on staying up late to study and sleeping in on weekends to catch up,” Duarte said. “This data shows that may not be the greatest strategy for optimizing memory ability.”

Learn more about how sleep – or lack of it – can affect your health at MindBodyScience.news.

Sources include:

ScienceDaily.com

FrontiersIn.org