A new study suggests that insomnia may be linked to a staggering 12 percent of dementia cases. If you’re used to measuring risk, this is a wake-up call to address your sleep hygiene as a hedge against cognitive decline. Marla Broadfoot dives into the data for Science News.

🗞️ News to lose sleep over

Researchers at Massachusetts General Hospital in Boston analyzed longitudinal data from nearly 6,000 participants in the National Health & Aging Trends Study to determine how sleep disturbances impact long-term cognitive health. The researchers focused on two primary indicators of insomnia, falling asleep and staying asleep — and used statistical modeling to calculate the percentage of dementia cases that could theoretically be prevented if these sleep issues were eliminated. They found that individuals who had trouble falling or staying asleep had a significantly higher risk of cognitive decline. The relationship is complicated: other research suggests sleep problems might be an effect of dementia rather than a cause. Taken together, the findings suggest that, while no cause-and-effect relationship between insomnia and dementia has been established, sleep problems are a modifiable risk factor and should therefore be examined more closely.