Deep sleep, also known as non-REM slow-wave sleep, can act as a ‘cognitive reserve factor’ that may increase resilience against a protein in the brain called beta-amyloid, which is linked to memory loss caused by dementia, says new research from a team at UC Berkeley. Disrupted sleep has previously been associated with faster accumulation of beta-amyloid protein in the brain. The study reveals that superior amounts of deep, slow-wave sleep can act as a protective factor against memory decline in those with a high risk of Alzheimer’s disease. This is a potentially significant advance that could help alleviate some of dementia’s most devastating outcomes. Researchers say that people should be aware that, despite having a certain level of pathology, there are certain lifestyle factors that will help moderate and decrease the effects.