Could daytime light exposure help protect against dementia?

by Wiley

edited by Stephanie Baum, reviewed by Robert Egan

Stephanie Baum

Scientific Editor

Meet our editorial team
Behind our editorial process

Robert Egan

Associate Editor

Meet our editorial team
Behind our editorial process Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

trusted source

proofread

The GIST Add as preferred source

New research in General Psychiatry has uncovered a link between higher levels of daytime light exposure and a lower risk of dementia.

For the study, investigators measured daytime and nighttime light exposure in 87,577 adults who wore accelerometers on their wrists. Over a median follow-up of 8.1 years, 741 participants developed dementia. Average daytime light exposure above 1,000 lux (a moderately bright light level equivalent to an overcast day outdoors) was associated with a 16% lower dementia risk. Longer exposure to bright daytime light (at least 5,000 lux) was associated with a further reduction in risk.

Less than 0.7 hours per day of bright daytime light was a stronger predictor of dementia than six established dementia risk factors. Nighttime light showed no significant association with dementia risk.

"Daytime light exposure may serve as a novel indicator of dementia risk," said corresponding author Hongliang Feng, Ph.D., of Guangzhou Medical University in China.

More information

Associations between wearable-device-measured daytime and nighttime light exposures and dementia risk: A prospective cohort study, General Psychiatry (2026). DOI: 10.1002/gps3.70039

Key medical concepts

Dementia

Clinical categories

NeurologyHealthy agingCommon illnesses & PreventionPreventive medicine Provided by Wiley Who's behind this story?

Stephanie Baum

Master's in TESOL from The New School. Passionate about language learning and editing science news on biology and space exploration. Full profile →

Robert Egan

Bachelor's in mathematical biology, Master's in creative writing. Well-traveled with unique perspectives on science and language. Full profile →

Citation: Could daytime light exposure help protect against dementia? (2026, June 17) retrieved 17 June 2026 from https://medicalxpress.com/news/2026-06-daytime-exposure-dementia.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.