A new artificial intelligence tool can decode your brain's age from your sleep, potentially revealing hidden dementia risk years before memory problems start. Researchers found that when the brain appears older than the body's chronological age, the risk of developing dementia rises sharply.
The Research
Scientists at the University of California, San Francisco, and Beth Israel Deaconess Medical Center in Boston developed a machine-learning model that analyzes brain waves during sleep. The model combines 13 microscopic features from EEG recordings to estimate a person's 'brain age.'
The team applied this model to data from about 7,000 adults aged 40 to 94, none of whom had dementia at the start. Over follow-up periods ranging from 3.5 to 17 years, about 1,000 participants developed dementia. The results were published in JAMA Network Open.
The findings were striking: for every 10-year increase between estimated brain age and actual age, the likelihood of developing dementia rose by nearly 40%. Conversely, those whose brain age was younger than their chronological age had a lower risk.
Importantly, these brain-age estimates captured subtle patterns that standard sleep metrics miss. Traditional measures like time in deep sleep or night awakenings did not show a strong link to dementia risk. Senior author Yue Leng, PhD, associate professor of psychiatry at UCSF, explained: 'Broad sleep metrics don't fully capture the complex multidimensional nature of sleep physiology.'
Among the EEG patterns used were delta waves (slow waves of deep sleep) and sleep spindles (bursts of activity that help consolidate memories). One notable feature, called kurtosis—large sudden spikes in EEG signals—was associated with a lower dementia risk, suggesting it may protect cognitive function.
Why It Matters
This tool could transform dementia screening. Since EEG can be recorded non-invasively, even with wearable devices, it may someday allow at-home risk assessment. 'Brain age is calculated from sleep brain waves,' Leng said. 'We know that brain activity during sleep provides a measurable window into how well the brain is aging.'
Early detection is crucial because interventions are most effective in the earliest stages of cognitive decline. This research also hints that improving sleep health might help slow brain aging.
What You Can Do
While there's no magic pill, you can support your brain health by maintaining good sleep hygiene and overall health. First author Haoqi Sun, PhD, noted that 'better body management, such as lowering body mass index and increasing exercise to reduce the likelihood of apnea, may have an impact.' Prioritize regular physical activity, a balanced diet, and address any sleep disorders like sleep apnea.
Source: ScienceDaily Mind & Brain
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