How long older adults sleep can affect their brain health one discovery Published Monday in the journal JAMA Neurology.
Disrupted sleep is common in late life, the study authors write, and is associated with changes in cognitive function Mental ability to learn, think, reason, problem solve, decide, remember and pay attention.
Age-related changes in sleep are also associated with early signal of Alzheimer’s disease, depression And heart disease, so the authors examined possible associations between self-reported sleep duration, demographic and lifestyle factors, subjective and objective cognitive function, and participants’ levels of beta amyloid.
Those in the study who reported shorter sleep duration — defined in the study as six hours or less — had elevated levels of beta amyloid, which is a “very high risk of dementia,” study lead author Jo. Viner, a postdoctoral research fellow at Stanford University in California, via email.
This was compared to participants who reported normal sleep duration, which the study authors defined as seven to eight hours of sleep per night.
Older adults with insufficient sleep also performed moderately to significantly worse on tests commonly used on older adults to assess cognitive abilities, including orientation, attention, memory, language and visual-spatial skills; and identifying mild dementia.
Sleeping too much was also associated with lower executive function, but those with no elevated beta amyloid levels. Participants who reported longer sleep duration (nine or more hours) scored slightly worse on the Digit Symbol Substitution Test than those who reported normal sleep duration. For more than a century, it test has been evaluated Associative learning skills by observing test takers’ ability to correctly match symbols with numbers according to a key on the page within 90 to 120 seconds.
“The main measure is that it’s important to maintain healthy sleep late in life,” Viner said via email. “Additionally, both people who sleep too little and those who get too much sleep have higher[body-mass index]and more depressive symptoms.” The findings suggested that different underlying disease processes may be involved in short and long sleep, Viner said.
beta amyloid 101
Beta amyloid or amyloid-beta “is a protein made during normal brain cell activity, although we are still not sure of its function,” Viner said.
“Amyloid-beta is one of the first detectable markers in the progression of Alzheimer’s disease, Viner said. “In Alzheimer’s disease, amyloid-beta proteins tend to build up throughout the brain, clumping together into plaques. Amyloid plaques are more likely to appear as we age, and many people with amyloid built up in their brains remain healthy. About 30% of healthy 70-year-olds will have a substantial amount of (of) amyloid plaques in their brains.”
When someone has Alzheimer’s disease, that person’s brain cells that retrieve, process and store information degenerate and die. Alzheimer’s Association. The “amyloid hypothesis”, one of the leading theories on the culprit of this destruction, suggests that the accumulation of proteins can disrupt communication between brain cells, eventually killing them.
Previous research has suggested that “sleep may help to both limit the production of amyloid in the brain and support the drainage system that clears it,” said Laura Phipps, head of communications at Alzheimer’s Research UK, who were not involved in the study. Via email.
Phipps said amyloid-beta can begin to form years before obvious Alzheimer’s symptoms appear. “This makes it difficult to tease apart cause-and-effect when studying sleep problems and Alzheimer’s risk, especially if you only look at one-time data.”
Sleep, Depression and Sociology
The current study analyzed 4,417 participants, mostly white and from the United States, Canada, Australia and Japan, with a mean age of 71.3 years.
Both the short and long sleep duration groups reported more depressive symptoms than the normal sleep group. Self-reported caffeine intake was not associated with sleep duration. But the more alcoholic beverages participants drank per day, the more likely they were to fall asleep.
There were also differences between gender, race and ethnicity: being female and having more years of education were both significantly associated with longer sleeping hours each night. And when compared with white participants, who reported an average sleep duration of seven hours and nine minutes, Viner said, black or African American participants reported an average sleep duration of 37.9 minutes less. Asian participants reported 27.3 minutes less than white participants, and Latino or Hispanic white participants reported 15 minutes less.
These findings suggest that sleep disparity may be linked to inequalities in other aspects of life, such as cardiovascular and metabolic health, socioeconomic factors and “racial discrimination and perceived racism” have been related to less sleep in prior studies, the authors said. has written.
Phipps said, “To better understand the order and direction of causality in these relationships, future research will need to build a picture of how sleep patterns, biological processes and cognitive skills change over long periods of time. “
“This new research is from a large, international study on cognitively healthy people, but it relied on participants to report their sleep duration rather than directly measuring it,” she said. “The researchers could not assess sleep quality or time spent in different phases of the sleep cycle, each of which may be an important factor in the link between sleep and cognitive health.”
Whether certain cognitive domains are affected more by duration of excessive sleep than other domains also remains controversial, the authors write.
Older adults concerned about these findings should consider sleep as important to their health as diet and exercise, Viner said.
“While researchers are still working to understand the complex relationship between sleep and our long-term cognitive health, high-quality sleep may be important for many aspects of our health and wellbeing,” Phipps said. “The best evidence suggests that seven to nine hours of sleep is optimal for most adults and anyone who thinks their sleep patterns may be affecting their long-term health should speak to their doctor.”