- Why Is Sleep Important?
- Take our Sleep Habits Test
- Find a sleep counsellor near me
Key points
- Sleep complaints are related to memory abilities and protein tangles in the brain in older women.
- Poor sleep linked to worse visual memory, but only in women with higher genetic risk for Alzheimer’s disease.
- Worse sleep linked to more neuropathology, but only in women with higher genetic risk for Alzheimer’s disease.
- Visual memory tasks may be more sensitive to the effects of poor sleep than verbal memory tasks.
Most of us have walked into a room and forgotten why, or struggled to remember where we last placed our keys. Some forgetfulness is a normal part of getting older. What if there were an everyday behavior that could be an early sign of something more serious for our memory and brain health? A recent research study by Lui and colleagues (2026) suggests that how well we sleep may matter more than we think, particularly for older women at a higher risk for Alzheimer’s disease.
Why Studying Women (and Their Sleep) Matters
We all know that sleep is helpful for attention and mood. But did you know it is also linked to brain changes associated with Alzheimer’s disease? Years before cognitive symptoms of Alzheimer’s disease emerge, a protein called tau can form tangles in brain regions that are important for memory and sleep. The tau tangles are a hallmark of Alzheimer’s disease, and poorer sleep can further their spread in the brain, resulting in memory decline.
Women are more likely to report sleep complaints and develop Alzheimer’s disease compared to men, highlighting the importance of examining these relationships in women. Women also tend to perform better on tests of verbal memory, such as remembering a story, compared to men. Although better memory performance is certainly helpful in our daily life, it can potentially mask early memory changes in women who perform normally on objective verbal memory tests in the clinic. One way to even the playing field is to use visual memory tests, such as remembering details of a picture or where an object was located. Sex differences appear to be smaller in visual memory tasks compared to verbal tasks, which may make visual memory tasks a more sensitive marker of memory decline.
Genetics also plays an important role in brain health and memory abilities. Oftentimes, genetic risk is determined by looking at a specific gene called apolipoprotein (APOE). Recent studies are measuring genetic risk with a polygenic hazard score that accounts for more genetic information than the APOE gene alone. These genetic measures help researchers identify who is most vulnerable to Alzheimer’s disease and who may benefit most from paying attention to their sleep.
Meet the Women of WITS
The Women: Inflammation Tau Study (WITS) is an ongoing study at the University of California San Diego. The study enrolls women 65 and older with a family history of dementia. To date, 63 women have participated. Genetic risk for Alzheimer’s was measured using a polygenic hazard score by combining information from many genes to categorize the women into a high-risk or low-risk group. Each participant filled out a questionnaire about their sleep health and completed verbal and visual memory tests. The verbal task examined their memory for a list of words, whereas the visual task examined their memory for objects and their locations. Tau tangles in the brain, which are considered a marker of Alzheimer’s disease, were detected with a tau positron emission tomography (PET) scan.
Key Findings for the High-risk Group
Interestingly, associations emerged only in women with higher genetic risk for Alzheimer’s disease. In the high-risk group, worse self-reported sleep was related to poorer performance on tasks of visual memory. Similarly, these individuals demonstrated greater levels of tau in limbic areas deep within the brain, which play a critical role in memory abilities and are often affected early in Alzheimer’s disease. In contrast, these relationships were not observed in the low-risk group or with verbal memory in either group.
What This Means for Brain Health and Early Detection
Based on their findings, Lui and colleagues concluded that poor sleep is associated with more tau tangles in certain brain regions and poorer visual memory performance, specifically in older women with higher genetic risk for Alzheimer’s disease
The authors suggest that improving sleep may provide some resilience against Alzheimer’s-related brain changes, although future longitudinal research in larger samples of individuals from diverse backgrounds is needed to confirm this. They also note that visual memory tests may be more sensitive to sleep-related memory impairment in women at elevated risk, and that a simple sleep questionnaire could serve as a quick and cost-effective tool for detecting early brain changes.
- Why Is Sleep Important?
- Take our Sleep Habits Test
- Find a sleep counsellor near me
Together, these findings suggest that the connection between sleep and the brain may be especially important for women at an elevated genetic risk for Alzheimer’s, and that visual memory tests may be picking up on subtle changes that verbal tests are missing. All of this is a reminder that sleep is about more than just feeling well-rested; it may be related to how our brains age over time
References
Lui, K. K., Wang, X., Dratva, M. A., Lifset, E. T., Stiver, J., Heyworth, N. C., Shen, Q., Thomas, M., DeYoung, P. N., Malhotra, A., Sundermann, E. E., & Banks, S. J. (2026). Sleep complaints and genetic risk of Alzheimer’s disease in older women: Associations with memory and tau deposition. The Journal of Prevention of Alzheimer’s Disease, 13(7), 100581. https://doi.org/10.1016/j.tjpad.2026.100581
