Heart damage linked to sleeping in low light, study finds

Key Points:

• A new study published in the European Heart Journal found that even small amounts of light exposure during sleep can thicken heart muscle walls and reduce heart function, increasing the risk of future heart disease.
• Researchers analyzed over 11,000 individuals from the UK Biobank and discovered that exposure to more than 3 lux of light at night led to cardiac remodeling, including thickening of the left ventricle and reduced heart muscle flexibility.
• Approximately 24% to 49% of the heart damage was linked to shorter sleep duration caused by nighttime light exposure, while other factors like stress and biological changes may account for the remaining risk.
• Experts recommend minimizing bedroom light to under 1 lux using blackout curtains, sleep masks, and dim, warm-colored bedside lights to protect heart health and improve sleep quality.
• Some limitations of the study include a short one-week measurement period and the use of wrist sensors to estimate light exposure, with experts calling for further research to confirm causality.