Does working night shifts raise the chances of Alzheimers disease? Research points to a likely connection through ongoing sleep disruption, but it is not proven as a direct cause yet.
Night shifts mess with your bodys natural clock, called the circadian rhythm. This clock tells you when to sleep and wake based on light and dark. When you work at night, your sleep gets chopped up or shorter. Over time, this can build up problems in the brain.
One key issue is proteins like amyloid beta and tau. These build up in the brain and are signs of Alzheimers. A study found that even one bad night of sleep in healthy middle-aged people raises amyloid beta levels. A full week of poor sleep boosts tau too. Experts say long-term bad sleep in middle age might raise Alzheimers risk later on. People with ongoing sleep issues, like from night shifts, could have higher levels of these proteins stuck around.
Deep sleep stages matter a lot. We go through light sleep, deep sleep, and REM sleep several times a night. Less time in deep sleep and REM links to brain changes seen early in Alzheimers. Brain areas that shrink in the disease get hit harder if you skimp on these stages. As we age, sleep quality drops anyway, so night shifts make it worse. Adults should aim for seven hours a night with good quality.
Night shifts are common. About 12 to 35 percent of Americans do them or rotating shifts. These irregular schedules disrupt sleep more than fixed ones. They tie to fatigue, anxiety, depression, and even migraines. While not all studies focus on Alzheimers, the sleep problems from night work match what harms the brain over years.
Naps might help a bit. Nurses on night shifts who took two-hour naps did better on memory tests. Their brain connections, seen on scans, bounced back some from sleep loss. But naps fix things only partway. Chronic night work still poses risks.
Over time, any sleep trouble links to faster thinking decline and higher Alzheimers rates. It is not clear if bad sleep causes the disease or comes with it. Still, fixing sleep could protect the brain.
Sources
https://medicine.washu.edu/news/sleep-alzheimers-link-explained/
https://www.thestreet.com/retirement/spending-less-time-in-2-deep-sleep-stages-may-contribute-to-alzheimers
https://medicalxpress.com/news/2025-12-night-shifts-deadly-disrupted-linked.html
https://pmc.ncbi.nlm.nih.gov/articles/PMC12728237/
https://www.psypost.org/two-hour-naps-during-night-shifts-may-restore-brain-function-and-memory-in-nurses/
https://www.psu.edu/news/health-and-human-development/story/night-waking-impacts-cognitive-performance-regardless-sleep
