Taiwan study finds good sleep quality may slow memory decline in elderly

台灣研究發現良好睡眠品質可減緩長者記憶力衰退

TAIPEI (Taiwan News) — A study by a medical team at Chang Gung Memorial Hospital found that good sleep quality in older adults helps maintain normal brain function and reduces memory decline.

Lee Shu-hua (李淑花), director of the Psychiatry Department at Linkou Chang Gung Memorial Hospital, said the team analyzed the sleep habits of 72 older adults aged between 66 and 88. During the study, participants underwent magnetic resonance imaging and completed a sleep quality questionnaire.

The study found that individuals with poorer sleep quality had weaker brain repair functions. Poor sleep quality was also observed to disrupt the brain's lymphatic system, which can negatively affect cognitive function, per CNA.

The brain's lymphatic system, which helps remove metabolic waste, is most active during deep sleep, Lee said. Therefore, when sleep quality declines, this clearing function is weakened, leading to the accumulation of toxins.

About 40% to 70% of older adults in Taiwan are affected by sleep problems. Lee noted that chronic insomnia could increase the risk of dementia, depression, and cardiovascular diseases. For sleep issues, most doctors initially recommend treatments that do not involve medication, such as establishing a consistent sleep schedule, staying active during the day, and getting more sunlight.

Liu Keng-hao (劉耕豪), a traditional Chinese medicine doctor at the hospital, said that avoiding stimulating foods before bedtime, reducing screen time, properly supplementing with Omega-3 fatty acids, and engaging in regular exercise can also help improve sleep quality.

Fang Chi-tsun (方基存), a nephrologist at the hospital, said the team also collaborated with the Department of Psychology at the University of Hong Kong to use advanced brain imaging technology to measure the brain's lymphatic system function and analyze its connection to brain structure.

Individuals with poor sleep quality showed lower readings in brain scans related to waste clearance pathways, indicating a reduced ability for the brain to remove waste, Fang said. He added that in those with poor sleep, coordinated activity between different brain regions was not observed.

The hospital’s research finding was published in the medical journal Molecular Psychiatry in October. By the end of this year, adults aged 65 and over will make up 20.7% of Taiwan’s population, according to the National Development Council. The hospital hopes the research will contribute to improved healthcare and cognitive treatment for older adults.