Study Links Long Sleep Duration to Increased Alzheimer’s-Related Protein Levels

The research reveals that sleep durations starting at eight-and-a-half to nine hours per night correspond to elevated p-tau181 levels, with a significant increase noted in those sleeping more than ten hours. Vanessa M. Young, PhD, a researcher at the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases and lead author of the study, emphasizes that while a direct cause-and-effect relationship cannot be established, these findings warrant further investigation into sleep habits and brain health.

The study, published on May 19 in the journal Alzheimer's & Dementia, also builds on previous research from 2025 that found a link between sleeping nine hours or more and cognitive decline, particularly in individuals with depression. Although both short and long sleep durations have been associated with Alzheimer's risk, this recent study examined the complex, non-linear relationships between sleep quantity and various Alzheimer’s-related biomarkers.

Dementia currently affects approximately 57 million people worldwide, with Alzheimer’s disease accounting for 60% to 70% of cases. Identifying modifiable risk factors such as sleep could be crucial for developing strategies to diagnose and delay the onset of this disease. By leveraging the Framingham Heart Study's extensive data, the researchers employed advanced modeling techniques to assess the influence of sleep on Alzheimer's biomarkers, specifically focusing on p-tau181.

The study posits that individuals who consistently sleep nine to ten hours or more should consider discussing their sleep habits with healthcare providers. Additional authors of the study are affiliated with various institutions, including Hospitals and universities across Canada, Spain, and Australia.