This Common Sleep Problem May Raise Dementia Risk By 40%
Most of us know how miserable a sleepless night feels the next morning. But beyond grogginess and brain fog, what does chronic insomnia actually mean for your long-term brain health? A new study suggests the impact is much more serious than we once thought.
Researchers found that chronic insomnia wasn’t just an inconvenience—it was tied to faster cognitive decline, more signs of brain aging, and a significantly higher risk of developing dementia.
The findings reinforce what sleep experts have been saying for years: prioritizing healthy sleep isn’t optional; it’s one of the most powerful tools we have to protect the brain as we age.
What the researchers found
Researchers followed more than 2,700 adults who were cognitively healthy at the start. Some had chronic insomnia—trouble falling or staying asleep at least three nights a week for three months or longer—while others did not.
Over nearly six years, participants completed annual memory and thinking tests, along with brain scans that looked for early signs of aging and Alzheimer’s disease. This allowed the researchers to see not just how well people were performing mentally, but also what was happening in their brains over time.
Here’s what they found:
- Higher dementia risk: People with chronic insomnia were about 40% more likely to develop mild cognitive impairment or dementia during the study period.
- Faster decline: Those with insomnia showed a quicker drop in global cognitive scores compared to good sleepers.
- Brain changes: Participants who reported insomnia and sleeping less than usual had more amyloid buildup, more white matter hyperintensities (a marker of vascular aging in the brain), and worse baseline cognitive scores, roughly equivalent to being four years older in brain age.
Catch more Zzz's for your brain's sake
So why does insomnia take such a toll? Sleep plays a critical role in “housekeeping” for the brain. During deep sleep, the glymphatic system clears away toxins like beta-amyloid proteins. When sleep is chronically disrupted, that cleanup process falters, leaving behind debris that can contribute to neurodegenerative diseases.
At the same time, poor sleep raises inflammation, impairs blood flow, and stresses white matter—all of which accelerate cognitive aging. It’s not just about feeling rested; it’s about giving your brain the nightly maintenance it needs to stay sharp for decades.
Practical ways to protect your sleep (& your brain)
The study’s findings are a wake-up call, but also a reminder that sleep is something we can influence. If you struggle with insomnia, small changes really do add up. Here are a few research-backed strategies to support deeper, more restorative rest:
- Anchor your schedule: Go to bed and wake up at consistent times (yes, even on weekends if you can!). Regularity strengthens circadian rhythms, which regulate sleep and brain health.
- Create a wind-down routine: Dim the lights, step away from screens, and try calming rituals like stretching, journaling, or breathing exercises an hour before bed.
- Light matters: Get bright light exposure in the morning (preferably sunlight) to help set your body clock, and limit artificial light at night.
- Try a magnesium supplement: Magnesium supports sleep by calming the nervous system, relaxing muscles, and regulating circadian rhythms.
- Address stress: Stress is one of the biggest drivers of restless nights, so finding ways to wind down during the day and before bed can make a real difference.
The takeaway
Chronic insomnia isn’t just frustrating; it’s a real risk factor for cognitive decline and dementia. This new study shows that even in adults who are otherwise healthy, poor sleep can accelerate brain aging and chip away at long-term resilience.
But don’t feel discouraged! Sleep is modifiable. By making consistent, intentional changes to your sleep hygiene and seeking support if insomnia persists, you’re not only protecting your nightly rest—you’re investing in your future brain health.
